Balloon catheter for foreign body removal

Abstract

In order to provide a balloon catheter for foreign matter removal which is capable of successfully removing foreign matter in the body to the outside even when an approach along a generally used route is difficult, and has a simple structure and good usability, this balloon catheter 100 for foreign matter removal has: a catheter tube 200 which is made of a flexible material and in which a balloon lumen 220 and a guide wire lumen 230 are formed in the axial direction; and a balloon 300 which is disposed near the distal end of the catheter tube 200 and is expanded with a fluid delivered from a fluid outlet. The most distal end of the catheter tube 200 has a tapered shape. A reinforcement tube 216 for improving the rigidity of the catheter tube 200 is inserted in the guide wire lumen 230. The balloon 300 expands eccentrically to the axial center of the catheter tube 200.

Description

[Technical field]

[0001] The present invention relates to a balloon catheter for removing foreign bodies, which is used for removing foreign bodies from the body, such as gallstones formed in the bile duct. [Background technology]

[0002] For example, a method using a balloon catheter for removing foreign bodies is known as a method for removing gallstones generated in the bile duct. For example, the following Patent Document 1 discloses a method in which a balloon catheter for removing foreign bodies is inserted into the bile duct from the duodenal papilla, and gallstones are scraped out of the bile duct from the duodenal papilla by a balloon provided at the distal end of the catheter tube. In this specification, the method of inserting a balloon catheter for removing foreign bodies into the bile duct from the duodenal papilla is called the ERCP (endoscopic retrograde cholangiopancreatography) approach.

[0003] In the endoscopic gallstone removal by the ERCP approach, as shown in Fig. 8, the tip of an endoscope 900 is placed near a duodenal papilla 940, which is the entrance of a bile duct 930, and a catheter tube 902 of a balloon catheter for removing foreign bodies is inserted from the duodenal papilla 940 into the bile duct 930 via the endoscope 900. Then, as shown in Fig. 9, a balloon 903 is positioned deep inside the bile duct 930, and the balloon 903 is inflated, and the catheter tube 902 is pulled back from inside the bile duct 930 toward the duodenal papilla 940 (the direction of the arrow in Fig. 9), so that a gallstone 950 present on the proximal end side of the balloon 903 can be scraped out of the bile duct 930 from the duodenal papilla 940. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-10297 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in cases such as duodenal stenosis, it may be difficult to insert a balloon catheter into the bile duct from the duodenal papilla, making the ERCP approach difficult.

[0006] The present invention aims to provide a balloon catheter for removing foreign bodies that is simply configured and highly convenient, and that is capable of effectively expelling foreign bodies, such as gallstones, that have formed in the bile duct from the body, even in cases where approach via a commonly used route such as the ERCP approach is difficult. [Means for solving the problem]

[0007] In order to achieve the above object, the balloon catheter for removing foreign bodies according to the present invention is a balloon catheter for removing foreign bodies used for removing foreign bodies from a body, comprising: a catheter tube made of a flexible material, the catheter tube having a balloon lumen formed therein along an axial direction, through which a fluid flows that is led out from a fluid lead-out port provided in the vicinity of a distal end, and a guidewire lumen through which a guidewire that is led out from a guidewire insertion hole provided at the most distal end is inserted; a balloon disposed near the distal end of the catheter tube and inflated by the fluid discharged from the fluid outlet; The distal end of the catheter tube is tapered, A reinforcing tube for improving the rigidity of the catheter tube is inserted into the guidewire lumen, The balloon is inflated eccentrically with respect to the axis of the catheter tube, which allows for the realization of a balloon catheter for removing foreign bodies that is simply configured and highly convenient, and that can effectively expel foreign bodies such as gallstones from the body through a puncture hole provided in body tissue such as the stomach wall or bile duct wall, even in cases where it is difficult to approach via a commonly used route such as an ERCP approach.

[0008] The balloon catheter for removing foreign bodies according to the present invention has a distal end of the catheter tube formed in a tapered shape, and has a configuration that improves guidewire tracking performance when proceeding along a guidewire and dilation (expansion) performance of body tissues. This allows the distal end of the balloon catheter for removing foreign bodies to easily and quickly place the balloon at a target site through a puncture hole provided in body tissues such as the stomach wall or bile duct wall.

[0009] In the balloon catheter for removing foreign bodies according to the present invention, a reinforcing tube for improving the rigidity of the catheter tube is inserted into the guidewire lumen, thereby realizing a configuration that improves the pushability of the catheter tube. Note that the pushability of the catheter tube means the pushing ability to transmit the pushing force acting at the proximal end to the distal end when the catheter tube is pushed axially from the proximal end to the distal end. This ensures that the pushing force acting at the proximal end is transmitted to the distal end, making it possible to move the balloon toward the distal end with a desired force.

[0010] In the balloon catheter for removing foreign bodies according to the present invention, the balloon is inflated eccentrically with respect to the axis of the catheter tube, so that the most distal end of the catheter tube can be positioned at a position offset from the center of the balloon, which makes it difficult for the most distal end of the catheter tube to come into contact with a foreign body, while ensuring that the balloon can come into contact with the foreign body and push it out.

[0011] In addition, the balloon catheter for removing foreign bodies according to the present invention is characterized in that the catheter tube is composed of a thin diameter section on the distal end side and a thick diameter section on the proximal end side having an outer diameter larger than that of the thin diameter section, and the reinforcing tube is inserted into the thick diameter section, thereby making it possible to improve the rigidity of the thick diameter section on the distal end side of the catheter tube while maintaining the flexibility of the thin diameter section on the distal end side of the catheter tube.

[0012] In addition, the balloon catheter for removing foreign bodies according to the present invention is characterized in that the reinforcing tube is made of polyether ether ketone, thereby making it possible to improve the rigidity of the catheter tube with a simple structure in which the reinforcing tube made of polyether ether ketone is inserted into the guidewire lumen.

[0013] The balloon catheter for removing foreign bodies according to the present invention is characterized in that, with the balloon in an inflated state, the catheter tube is pushed from the proximal end side to the distal end side, and the balloon moves through the bile duct toward the duodenal papilla, thereby pushing foreign bodies in the bile duct out of the bile duct at the distal end side of the balloon. This makes it possible to realize a balloon catheter for removing foreign bodies with a simple configuration and excellent convenience, which can be used even when the ERCP approach is difficult, by placing a balloon in the bile duct through a puncture hole provided in body tissue such as the stomach wall or bile duct wall, and pushing foreign bodies such as gallstones formed in the bile duct out of the bile duct at the distal end side of the balloon toward the duodenal papilla. [Brief description of the drawings]

[0014] [Figure 1] 1 is a plan view showing an example of the configuration of a balloon catheter for removing foreign bodies according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is an enlarged side view of the vicinity of region X in FIG. [Diagram 3] 2 is a cross-sectional view showing a cross section AA of FIG. 1. [Figure 4] FIG. 2 is a schematic axial cross-sectional view of the vicinity of region Y in FIG. [Diagram 5] 2 is a schematic axial cross-sectional view of the vicinity of region Z in FIG. 1. [Figure 6] FIG. 2 is a schematic diagram for explaining an example of use of the foreign body removal balloon catheter according to the embodiment of the present invention for removing gallstones from a bile duct. [Figure 7A] FIG. 13 is a schematic diagram showing a comparative example of the embodiment of the present invention, in which the center of a balloon is positioned so as to coincide with the axis of a catheter tube. [Figure 7B] FIG. 2 is a schematic diagram showing an embodiment of the present invention in which the center of a balloon is disposed at a position offset from the axis of a catheter tube. [Figure 8] FIG. 1 is a schematic diagram for explaining an example of the use of a balloon catheter for removing foreign bodies according to the prior art to remove gallstones from a bile duct. [Figure 9] FIG. 9 is an enlarged view of the duodenal papilla and the vicinity of the bile duct in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] Fig. 1 is a plan view showing an example of the configuration of a balloon catheter for removing foreign bodies according to an embodiment of the present invention. The balloon catheter for removing foreign bodies 100 shown in Fig. 1 is used, for example, via an endoscope, and includes a catheter tube 200, a balloon 300, a branching section 400, and three branch tubes 500a to 500c.

[0017] In the following description, the extension direction of the foreign body removal balloon catheter 100 is defined as the axial direction, the balloon 300 side of the foreign body removal balloon catheter 100 is defined as the distal end side, and the three branch tubes 500a to 500c side of the foreign body removal balloon catheter 100 is defined as the proximal end side.

[0018] The catheter tube 200 is a tube made of a flexible material. In Fig. 1, the catheter tube 200 is not shown in the middle, but in reality, the catheter tube 200 is connected and has an elongated shape in the axial direction.

[0019] The catheter tube 200 has a small diameter section 210 at the distal end side that is inserted into the body via an endoscope, and a large diameter section 215 at the proximal end side of the small diameter section 210. The total length of the catheter tube 200 is, for example, 500 to 2500 mm, and the axial dimension of the small diameter section 210 is 30 to 800 mm. The outer diameter of the small diameter section 210 is 50 to 95% of the outer diameter of the large diameter section 215, for example, 1.0 to 4.2 mm. The material of the catheter tube 200 is not particularly limited as long as it is flexible, but from the viewpoint of moldability, a thermoplastic resin or a thermoplastic elastomer is suitable, and for example, a polyamide resin or a polyamide-based elastomer can be used.

[0020] One or more contrast rings 250 are attached to the small diameter section 210 of the catheter tube 200. For example, two contrast rings 250 are attached to the catheter tube 200 shown in Fig. 1 near the attachment position of the balloon 300, but the shape of the contrast rings 250, the position at which the contrast rings 250 are attached, the number of contrast rings 250, etc. are not particularly limited. The contrast rings 250 are used to confirm the position of the distal end of the catheter tube 200 by X-ray imaging when the distal end is inserted into the body, and thus the position of the balloon 300 can be confirmed. The contrast rings 250 can be made of a metal such as gold, platinum, or tungsten.

[0021] A tapered section 211 formed in a tapered shape is provided at the most distal end of the small diameter section 210 of the catheter tube 200. The tapered section 211 is provided in order to improve the dilation performance when passing through a puncture hole provided in body tissue such as the stomach wall or a body lumen.

[0022] Fig. 2 is an enlarged side view of the vicinity of region X in Fig. 1. As shown in Fig. 2, tapered portion 211 has an inclination such that it tapers from the most distal end to a dimension L1 in the axial direction, and is formed so that the outer diameter of the most distal end is smaller than the outer diameter of the straight body portion of thin-diameter portion 210. The dimension L1 in the axial direction of tapered portion 211 is not particularly limited, but is, for example, 0.5 to 20 mm. In addition, tapered portion 211 may have a tapered shape, and the inclination angle of tapered portion 211, the dimension of the outer diameter of the most distal end, and the like are not particularly limited.

[0023] The method for providing the tapered portion 211 formed in a tapered shape is not particularly limited, but for example, the tapered portion 211 can be formed in a tapered shape by processing the most distal end of the catheter tube 200 using a molding die or the like. Alternatively, the most distal end of the catheter tube 200 may be formed in a tapered shape by forming a member including the tapered portion 211 and joining the member thus formed to the distal end of the catheter tube 200.

[0024] The catheter tube 200 is a multi-lumen tube. Inside the catheter tube 200, as shown in Fig. 3, for example, a balloon lumen 220, a guidewire lumen 230, and a contrast medium lumen 240 are formed, and the lumens 220 to 240 are isolated from each other.

[0025] The balloon lumen 220 is a lumen used as a flow path for sending a fluid such as air into the balloon 300 in order to expand and contract the balloon 300. The balloon lumen 220 penetrates from the proximal end of the catheter tube 200 to a fluid communication port (not shown). The fluid communication port is an opening provided in the small diameter portion 210 of the catheter tube 200 that opens into the inside of the balloon 300. As will be described later, the balloon lumen 220 communicates with a branch pipe 500a at the branch portion 400.

[0026] The guidewire lumen 230 is a lumen used as a path for inserting a guidewire 235. The guidewire lumen 230 penetrates from the proximal end of the catheter tube 200 to a guidewire insertion hole 231 at the distal end. The guidewire insertion hole 231 is an opening that opens at the distal end of the catheter tube 200. As will be described later, the guidewire lumen 230 communicates with a branch tube 500b at the bifurcation portion 400.

[0027] The contrast medium lumen 240 is a lumen used as a flow path of the contrast medium in X-ray imaging. The contrast medium lumen 240 penetrates from the proximal end of the catheter tube 200 to a contrast medium outlet (not shown). The contrast medium outlet is an opening provided in the small diameter portion 210 of the catheter tube 200. The foreign body removal balloon catheter 100 according to the embodiment of the present invention is particularly suitable for pushing out gallstones in the bile duct located in front of it with the balloon 300. For example, by providing a contrast medium outlet on the distal end side of the balloon 300, it becomes possible to eject the contrast medium toward the gallstones in the bile duct. In addition, as described later, the contrast medium lumen 240 communicates with a branch duct 500c at the bifurcation portion 400.

[0028] The cross-sectional shapes of the balloon lumen 220, the guidewire lumen 230, and the contrast agent lumen 240 may be any shape that allows efficient arrangement within the catheter tube 200, but since a reinforcing tube 216 is inserted into the guidewire lumen 230 and a guidewire 235 inserted into the reinforcing tube 216 generally has a circular cross-sectional shape, it is preferable that the cross-sectional shape of the guidewire lumen 230 is approximately circular. Furthermore, the cross-sectional areas of the balloon lumen 220, the guidewire lumen 230, and the contrast agent lumen 240 are not particularly limited, but it is preferable that the cross-sectional area of ​​the guidewire lumen 230 is set relatively large compared to the cross-sectional areas of the balloon lumen 220 and the contrast agent lumen 240. For example, the cross-sectional area of ​​the balloon lumen 220 is 0.03 to 1.0 mm 2 The cross-sectional area of ​​the guidewire lumen 230 is 0.5 to 6.0 mm 2The cross-sectional area of ​​the contrast medium lumen 240 is 0.08 to 4.0 mm 2 It is.

[0029] In addition, a reinforcing tube 216 that improves the pushability of the catheter tube 200 is inserted into the guidewire lumen 230 over the entire large-diameter section 215, i.e., over the range from the proximal end to the distal end of the large-diameter section 215. By inserting the reinforcing tube 216 into the guidewire lumen 230 so as to extend in the axial direction, the rigidity of the catheter tube 200, particularly the axial rigidity and bending rigidity of the catheter tube 200, is increased, and the pushability of the catheter tube 200 can be improved.

[0030] The reinforcing tube 216 is preferably a tube having a circular cross section because the guidewire 235 inserted into the reinforcing tube 216 generally has a circular cross section. The outer diameter of the reinforcing tube 216 is approximately the same as the inner diameter of the guidewire lumen 230, and is a dimension that allows the reinforcing tube 216 to be inserted in close contact with the inner circumferential surface of the guidewire lumen 230. The inner diameter of the reinforcing tube 216 is larger than the outer diameter of the guidewire 235, and is a dimension that allows the guidewire 235 to be inserted. The material of the reinforcing tube 216 is not particularly limited, but a thermoplastic resin is suitable from the viewpoint of moldability and rigidity, and among them, it is particularly preferable to use polyether ether ketone (PEEK), which has high rigidity.

[0031] The reinforcing tube 216 inserted into the guidewire lumen 230 will be described with reference to FIGS.

[0032] Fig. 3 is a cross-sectional view showing the AA cross section of Fig. 1. As shown in Fig. 3, a balloon lumen 220, a guidewire lumen 230, and a contrast medium lumen 240 are formed in a large diameter section 215 of a catheter tube 200, and a reinforcing tube 216 is inserted into the guidewire lumen 230.

[0033] It should be noted that the cross-sectional view of the catheter tube 200 in Fig. 3 is an example, and the cross-sectional shape of each of the lumens 220 to 240 is not limited to the shape shown in Fig. 3. Although a three-lumen type catheter tube is illustrated as an example in Fig. 3, a two-lumen type catheter tube having two lumens used as, for example, the balloon lumen 220 and the guidewire lumen 230 may be used. In this example, the reinforcing tube 216 is inserted only into the guidewire lumen 230, but the reinforcing tube 216 may be inserted into one or both of the balloon lumen 220 and the contrast medium lumen 240.

[0034] Fig. 4 is a schematic axial cross-sectional view of the vicinity of region Y in Fig. 1. Fig. 4 illustrates the vicinity of the boundary between the small diameter section 210 and the large diameter section 215 of the catheter tube 200, and illustrates a state in which three lumens, a balloon lumen 220, a guidewire lumen 230, and a contrast agent lumen 240, are provided inside the catheter tube 200.

[0035] 4, three lumens, namely, balloon lumen 220, guidewire lumen 230, and contrast medium lumen 240, are formed inside thin diameter section 210 and thick diameter section 215, and each of lumens 220-240 inside thin diameter section 210 communicates with each of lumens 220-240 inside thick diameter section 215. The outer diameter of thin diameter section 210 is smaller than the outer diameter of thick diameter section 215, and the cross-sectional area of ​​each of lumens 220-240 inside thin diameter section 210 is also smaller than the cross-sectional area of ​​each of lumens 220-240 inside thick diameter section 215. Reinforcing tube 216 is inserted into guidewire lumen 230 inside thick diameter section 215, and the distal end of reinforcing tube 216 is located near the distal end of thick diameter section 215 and near the boundary between thin diameter section 210 and thick diameter section 215. Reinforcing tube 216 has, for example, an outer diameter that is approximately the same as or slightly smaller than the inner diameter of thick diameter portion 215 and larger than the inner diameter of thin diameter portion 210, and can be inserted into thick diameter portion 215 but cannot be inserted into thin diameter portion 210.

[0036] Fig. 5 is a schematic axial cross-sectional view of the vicinity of region Z in Fig. 1. Fig. 5 illustrates the connection between the large diameter portion 215 of the catheter tube 200 and each of the branch tubes 500a to 500c, i.e., the vicinity of the branch portion 400, and illustrates a state in which three lumens, the balloon lumen 220, the guidewire lumen 230, and the contrast medium lumen 240, are provided inside the catheter tube 200. Note that the capacitance tag 700 illustrated in Fig. 1 is omitted in Fig. 5.

[0037] As shown in Fig. 5, three lumens, namely, balloon lumen 220, guidewire lumen 230, and contrast medium lumen 240, are formed inside large diameter portion 215, and each of lumens 220-240 inside large diameter portion 215 communicates with each of branch tubes 500a-500c. Reinforcing tube 216 is inserted into guidewire lumen 230 inside large diameter portion 215, and the proximal end of reinforcing tube 216 is located near the proximal end of large diameter portion 215 and near the boundary between large diameter portion 215 and branch tube 500b. Note that the method for communicating each of lumens 220-240 with each of branch tubes 500a-500c is not particularly limited, but Fig. 5 shows, as an example, a state in which the distal ends of each of branch tubes 500a-500c are inserted into each of lumens 220-240 to communicate with each other.

[0038] 4 and 5, the reinforcing tube 216 is inserted into the guidewire lumen 230 from near the boundary between the small diameter section 210 and the large diameter section 215 to near the boundary between the large diameter section 215 and the branch pipe 500b, i.e., over the entire large diameter section 215. There are no particular limitations on the method for inserting the reinforcing tube 216 into the large diameter section 215 of the catheter tube 200, but for example, it is possible to insert the reinforcing tube 216 into the large diameter section 215 before communicating the guidewire lumen 230 of the catheter tube 200 with the branch pipe 500c.

[0039] Specifically, a catheter tube 200 having a small diameter portion 210 on the distal end side and a large diameter portion 215 on the proximal end side is prepared, and a reinforcing tube 216 is inserted into a guidewire lumen 230 that opens to the proximal end face of the large diameter portion 215 on the proximal end side, and the reinforcing tube 216 is pushed toward the distal end side. When the distal end of the pushed reinforcing tube 216 reaches the vicinity of the boundary between the small diameter portion 210 and the large diameter portion 215, it cannot enter the inside of the small diameter portion 210 having a small cross-sectional area, and is in a state of abutting against the distal end of the small diameter portion 210. In this state, the reinforcing tube 216 protruding from the proximal end face of the large diameter portion 215 is cut to match the proximal end face of the large diameter portion 215, thereby realizing a state in which the reinforcing tube 216 is inserted into the guidewire lumen 230 over the entire large diameter portion 215. In the embodiment of the present invention, since the reinforcing tube 216 is prevented from slipping out of the guidewire lumen 230 by connecting the branch tube 500b to the reinforcing tube 216 as described below, the reinforcing tube 216 and the guidewire lumen 230 are not directly fixed to each other. However, if necessary, the reinforcing tube 216 and the guidewire lumen 230 may be fixed to each other by means of adhesion using an adhesive or the like.

[0040] The balloon 300 is a cylindrical thin film that can be expanded by introducing a fluid thereinto, and is attached to the small diameter section 210 of the catheter tube 200 so as to cover a fluid outlet port (not shown). The balloon 300 is made of an elastic material, and is expanded by introducing a fluid thereinto through the balloon lumen 220 and the fluid outlet port of the catheter tube 200. In the embodiment of the present invention, it is possible to remove foreign matter from within the body by pushing out foreign matter such as gallstones with the distal end side of the inflated balloon 300.

[0041] The elastic material forming the balloon 300 preferably has a 100% modulus (a value measured in accordance with JIS K 6251) of 0.1 to 10 MPa, and particularly preferably 1 to 5 MPa. Specific examples of elastic materials suitable for forming the balloon 300 include natural rubber, silicone rubber, and polyurethane elastomer.

[0042] The balloon 300 is generally cylindrical, and has bonding parts 310, 320 formed on the distal end and proximal end to be bonded to the outer circumferential surface of the catheter tube 200. The bonding parts 310, 320 refer to the parts where the balloon 300 is bonded to the outer circumferential surface of the catheter tube 200 in a cylindrical shape, and the axial dimension of the bonding parts 310, 320 is, for example, 0.5 to 5.0 mm. The method for bonding the bonding parts 310, 320 of the balloon 300 to the outer circumferential surface of the catheter tube 200 is not particularly limited, and may be, for example, adhesion using an adhesive, heat fusion, welding with a solvent, ultrasonic welding, or the like.

[0043] Between the joints 310 and 320 of the balloon 300, an expansion part 330 is formed that is not joined to the outer circumferential surface of the catheter tube 200 and expands when a fluid is introduced therein. The expansion part 330 of the balloon 300 preferably has a maximum outer diameter in an expanded state of 200 to 1500% of the outer diameter in a deflated state. If this ratio is too small, the balloon 300 may not expand to a sufficient size, and if it is too large, the balloon 300 may get in the way when the catheter tube 200 is inserted into the body. The axial dimension of the expansion part 330 is, for example, 5 to 20 mm, and the membrane thickness is, for example, 0.10 to 0.50 mm.

[0044] In addition, an offset sheet 340 is attached to a part of the expansion section 330 so that the expansion section 330 expands eccentrically with respect to the axial center of the catheter tube 200. The offset sheet 340 has, for example, an elongated shape in which the axial dimension of the offset sheet 340 is set longer than the axial dimension of the expansion section 330. The offset sheet 340 is attached to a part of the expansion section 330 along the axial direction, and both ends of the offset sheet 340 are fixed to the joints 310, 320 or the outer circumferential surface of the catheter tube 200.

[0045] Since the part of the expansion section 330 to which the offset sheet 340 is attached is fixed to the catheter tube 200, the expansion section 330 on the side to which the offset sheet 340 is attached is in a state in which it is difficult to expand or cannot expand at all. As a result, the expansion section 330 on the side to which the offset sheet 340 is not attached expands unevenly, and expands into a shape eccentric with respect to the axis of the catheter tube 200.

[0046] The material of the offset sheet 340 is not particularly limited, and for example, the same resin as that of the catheter tube 200 can be used. The fixing method of the offset sheet 340 is not particularly limited, and for example, adhesion, heat fusion, high frequency fusion, etc. are possible. As an example, an offset sheet 340 with an adhesive applied to the back surface is used, and the offset sheet 340 is adhered to a part of the circumferential direction of the balloon 300 including the expansion part 330 and a part of the catheter tube 200. The width of the offset sheet 340 is, for example, 1 / 2 or less of the circumferential length of the outer circumferential surface of the catheter tube 200, and preferably 1 / 3 to 1 / 5. If this width is too small, it is difficult to inflate the balloon 300 in an eccentric state, and if this width is too large, it is difficult for the balloon 300 to inflate at all.

[0047] In the embodiment of the present invention, the balloon 300 is inflated into a shape eccentric with respect to the axis of the catheter tube 200 by attaching the offset sheet 340. However, the balloon 300 may be inflated in an eccentric state with respect to the axis of the catheter tube 200 by using a configuration other than the above, for example, by providing the expansion portion 330 so as to be offset to a part of the outer circumferential surface of the catheter tube 200.

[0048] The branching section 400 is a member provided at a connection section that connects the catheter tube 200 and the branch tubes 500a to 500c. In the branching section 400, the balloon lumen 220 communicates with the branch tube 500a, the inner cavity of the reinforcing tube 216 inserted in the guidewire lumen 230 communicates with the branch tube 500b, and the contrast medium lumen 240 communicates with the branch tube 500c. The method for connecting each lumen 220 to 240 in the catheter tube 200 or the inner cavity of the reinforcing tube 216 with each branch tube 500a to 500c is not particularly limited, and for example, a method of tapering the distal end of each branch tube 500a to 500c, inserting the tapered portion into the corresponding lumen 220 to 240, and fixing with an adhesive can be used. At this time, it is preferable to cover and protect the connection parts connecting the catheter tube 200 and the branch pipes 500a-500c with the branch part 400, which is a cylindrical cover member made of a polymeric material such as synthetic resin. The material of the branch pipes 500a-500c is not particularly limited, and for example, a polymeric material such as synthetic resin can be used.

[0049] The branch pipe 500a is a balloon branch pipe, and a balloon hub 600a equipped with, for example, a two-way stopcock is connected to the proximal end of the branch pipe 500a. The balloon hub 600a and the branch pipe 500a communicate with the balloon lumen 220 at the branching portion 400, so that a fluid can be introduced into the balloon 300 from the balloon hub 600a through the branch pipe 500a, the balloon lumen 220, and the fluid communication port.

[0050] Branch tube 500b is a guidewire branch tube, and a guidewire hub 600b of, for example, a luer lock type is connected to the proximal end of branch tube 500b. Guidewire hub 600b and branch tube 500b communicate with the inner cavity of reinforcing tube 216 inserted into guidewire lumen 230 at bifurcation 400, so that guidewire 235 can be protruded to the outside from guidewire hub 600b through branch tube 500b, reinforcing tube 216, guidewire lumen 230, and guidewire insertion hole 231 provided at the distal end of catheter tube 200.

[0051] Branch tube 500c is a branch tube for imaging, and a lure-lock type hub for imaging 600c is connected to the proximal end of branch tube 500c. Hub for imaging 600c and branch tube 500c communicate with contrast medium lumen 240 at branching portion 400, and contrast medium can be ejected from hub for imaging 600c through branch tube 500c, contrast medium lumen 240, and a contrast medium outlet port to the outside.

[0052] A capacitance tag 700 is attached to the outer periphery of the catheter tube 200 on the distal end side of the branching portion 400. The capacitance tag 700 describes information specific to the balloon catheter 100 for removing foreign bodies, such as the relationship between the outer diameter of the balloon 300 and the internal pressure or gas volume of the balloon 300.

[0053] As described above, the foreign body removal balloon catheter 100 in the embodiment of the present invention has a first feature in that the tapered section 211 is formed at the distal end of the catheter tube 200, a second feature in that the reinforcing tube 216 for improving the rigidity of the catheter tube 200 is inserted into the guidewire lumen 230, and a third feature in that the balloon 300 is configured to inflate eccentrically with respect to the axis of the catheter tube 200.

[0054] Focusing on the above-mentioned first to third features, an example of use of the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention will be described below with reference to Fig. 6. Note that the example of use described below is an example in which puncture holes are made in the stomach wall and intrahepatic bile duct wall (liver) of a patient in a case where it has been confirmed that the ERCP approach is difficult due to circumstances such as stricture in the patient's duodenum, and the balloon catheter 100 for removing foreign bodies is inserted into the bile duct through the puncture holes.

[0055] As shown in Fig. 6, when a gallstone 850 is removed from a bile duct 830 using a foreign body removal balloon catheter 100 according to an embodiment of the present invention, first, the tip of an endoscope 800, which is an ultrasonic endoscope, is inserted into the body, and an intrahepatic bile duct 820 is depicted as an ultrasonic image from a stomach 810 to the intrahepatic bile duct 820 to confirm the position of the intrahepatic bile duct 820. Next, while observing the ultrasonic image, a puncture needle is inserted into the intrahepatic bile duct 820 from a digestive tract wall such as a stomach wall, and a guide wire (not shown in Fig. 6) inserted into the foreign body removal balloon catheter 100 via the endoscope 800 is inserted from the intrahepatic bile duct 820 to the bile duct 830 through the puncture hole. Thereafter, the foreign body removal balloon catheter 100 is inserted into the body with the balloon 300 contracted, and the distal end of the catheter tube 200 is inserted from the intrahepatic bile duct 820 to the bile duct 830 through the puncture hole while being aligned with the guide wire (not shown in Fig. 6).

[0056] Next, a contrast medium is sprayed while the balloon 300 is placed in the bile duct 830, and the state of the inside of the bile duct 830 and the gallstone 850 is confirmed by an X-ray contrast image, and then the balloon 300 is inflated. Then, by pushing the proximal end of the catheter tube 200 toward the distal end (the direction of the arrow in FIG. 6) while the balloon 300 is inflated, the balloon 300 moves inside the bile duct 830 toward the duodenal papilla 840 (the direction of the arrow in FIG. 6), and the distal end side of the inflated balloon 300 pushes the gallstone 850 out of the bile duct 830 from the duodenal papilla 840, thereby removing it.

[0057] As described above, the foreign body removal balloon catheter 100 in the embodiment of the present invention is preferably used when the ERCP approach is difficult, and is used, for example, by inserting the distal end of the catheter tube 200 from the intrahepatic bile duct to the bile duct through puncture holes provided in the stomach wall and the intrahepatic bile duct wall. However, the puncture holes and body lumens such as the intrahepatic bile duct are very narrow, and it is not easy to insert the distal end of the catheter tube of a conventional balloon catheter into the puncture hole or to advance it through the body lumen.

[0058] In contrast, in the foreign body removal balloon catheter 100 according to the embodiment of the present invention, the distal end of the catheter tube 200 is tapered so that the distal end of the catheter tube 200 can proceed while expanding the path without damaging body tissue such as the peripheral wall of the puncture hole. That is, the foreign body removal balloon catheter 100 according to the embodiment of the present invention has a first feature in which the distal end of the catheter tube 200 is tapered, thereby realizing a configuration that improves guidewire tracking ability and dilation performance when proceeding along the guidewire 235.

[0059] As described above, when removing gallstones using the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, unlike the conventional ERCP approach of inserting a balloon catheter into the bile duct in a retrograde manner, the balloon catheter 100 for removing foreign bodies is inserted into the bile duct in an antegrade manner, and the balloon 300 is inflated while the proximal end of the catheter tube 200 is pushed toward the distal end to move the balloon 300 toward the distal end, and the gallstones are pushed out of the bile duct from the duodenal papilla at the distal end side of the balloon 300. However, in the conventional balloon catheter, the pushing force applied to the proximal end of the catheter tube may not be reliably transmitted to the distal end of the catheter tube. As a result, the balloon may not be moved toward the distal end with the desired force, and the gallstones may not be pushed out of the bile duct at the distal end side of the balloon.

[0060] In contrast, in the foreign body removal balloon catheter 100 according to the embodiment of the present invention, the reinforcing tube 216 that improves the rigidity of the catheter tube 200 is inserted into the guidewire lumen 230, so that the pushing force applied to the proximal end of the catheter tube 200 is reliably transmitted to the distal end of the catheter tube 200, and the balloon 300 can be moved toward the distal end with a desired force. That is, the foreign body removal balloon catheter 100 according to the embodiment of the present invention has a second feature in which the reinforcing tube 216 that improves the rigidity of the catheter tube 200 is inserted into the guidewire lumen 230, thereby realizing a configuration that improves pushability (pushability) in which the pushing force applied to the proximal end of the catheter tube 200 is transmitted to the distal end of the catheter tube 200.

[0061] As described above, when removing gallstones using the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, the gallstones are pushed out by the distal end side of the inflated balloon 300, unlike the conventional ERCP approach in which the gallstones are scraped out by the proximal end side of the balloon. However, when using a conventional balloon catheter to push out gallstones present at the distal end side of the balloon, the most distal end of the catheter tube may hit the gallstones when moving the balloon toward the distal end, hindering the movement of the catheter tube toward the distal end. As a result, the balloon may not be moved toward the distal end, and the gallstones may not be pushed out of the bile duct at the distal end side of the balloon.

[0062] In contrast, in the foreign body removal balloon catheter 100 according to the embodiment of the present invention, the balloon 300 expands eccentrically with respect to the axial center of the catheter tube 200, so that the distal end of the catheter tube 200 can be positioned at a position offset from the center of the balloon 300. That is, due to the third feature that the balloon 300 expands eccentrically with respect to the axial center of the catheter tube 200, the foreign body removal balloon catheter 100 according to the embodiment of the present invention can position the distal end of the catheter tube 200 at a position that does not get in the way when the balloon 300 hits a gallstone, and a configuration is realized that enables the balloon 300 to reliably hit the gallstone and push it out.

[0063] The third feature will be described in more detail with reference to Figures 7A and 7B. Figure 7A is a diagram of a comparative example for the embodiment of the present invention, and is a schematic diagram showing a case where the center of the balloon 300 is disposed at a position that coincides with the axis of the catheter tube 200. On the other hand, Figure 7B is a diagram of the embodiment of the present invention, and is a schematic diagram showing a case where the center of the balloon 300 is disposed at a position offset from the axis of the catheter tube 200.

[0064] As shown in Fig. 7A, when the center of the balloon 300 coincides with the axis of the catheter tube 200, the balloon 300 moves toward the distal end (the direction of the arrow in Fig. 7A) with the distal end of the catheter tube 200, where the tapered portion 211 is formed, positioned approximately at the center of the balloon 300. In this case, the distal end of the catheter tube 200 hits the gallstone 850, preventing the catheter tube 200 from moving toward the distal end, and the balloon 300 cannot move toward the distal end, making it impossible to push out the gallstone 850 at the distal end of the balloon 300.

[0065] On the other hand, as shown in Fig. 7B, when the center of the balloon 300 is positioned offset from the axis of the catheter tube 200, the balloon 300 moves in the distal end direction (the direction of the arrow in Fig. 7B) with the distal end of the catheter tube 200, where the tapered portion 211 is formed, positioned to the side with respect to the moving direction of the balloon 300. In this case, the distal end side of the balloon 300 can be successfully pressed against the gallstone 850 without the distal end of the catheter tube 200 hitting the gallstone 850, and the gallstone 850 can be reliably pushed out by the distal end side of the balloon 300.

[0066] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, the elements disclosed in the above-described embodiments are intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0067] For example, in the above-mentioned embodiment, the balloon catheter 100 for removing foreign bodies is described as being used to make puncture holes in the stomach wall and the intrahepatic bile duct wall (liver) of a patient, and is inserted from the intrahepatic bile duct into the bile duct through the puncture holes to discharge (remove) foreign bodies such as gallstones from the bile duct, but the balloon catheter for removing foreign bodies according to the present invention is not limited to this, and can be used in other cases as a balloon catheter for removing foreign bodies. However, the balloon catheter for removing foreign bodies according to the present invention is particularly suitable for use in an approach via a puncture hole made in body tissue in cases where an approach via a commonly used route such as an ERCP approach is difficult. [Explanation of symbols]

[0068] 100 Balloon catheter for removing foreign bodies 200, 902 Catheter tube 210 Thin section 211 Tapered section 215 Large diameter part 216 Reinforcing tube 220 balloon lumens 230 Guidewire lumen 231 Guidewire insertion hole 235 Guidewire 240 Contrast Lumen 250 Contrast Ring 300 Balloon 310, 320 joint 330 Expansion section 340 Offset Sheet 400 Branch 500a~500c Branch pipe 600a balloon hub 600b Guidewire Hub 600c Imaging Hub 700 capacity tag 800, 900 Endoscope 810 Stomach 820 Intrahepatic bile duct 830, 930 Bile duct 840, 940 duodenal papilla 850, 950 Gallstones

Claims

1. A balloon catheter for removing foreign bodies used to remove foreign bodies from the body, comprising: a catheter tube made of a flexible material, the catheter tube having a balloon lumen formed therein along an axial direction, through which a fluid flows that is led out from a fluid lead-out port provided in the vicinity of a distal end, and a guidewire lumen through which a guidewire that is led out from a guidewire insertion hole provided at the most distal end is inserted; a balloon disposed near the distal end of the catheter tube and inflated by the fluid discharged from the fluid outlet; The distal end of the catheter tube is tapered, A reinforcing tube for improving the rigidity of the catheter tube is inserted into the guidewire lumen, the catheter tube is composed of a small diameter portion on the distal end side and a large diameter portion on the proximal end side having an outer diameter larger than that of the small diameter portion, the reinforcing tube being inserted into the large diameter portion, 1. A balloon catheter for removing foreign bodies, wherein the balloon is inflated eccentrically with respect to the axis of the catheter tube.

2. 2. The balloon catheter for removing foreign bodies according to claim 1, wherein the reinforcing tube is made of polyether ether ketone.

3. 3. The balloon catheter for removing foreign bodies according to claim 1, wherein the catheter tube is pushed from the proximal end to the distal end while the balloon is in an inflated state, so that the balloon moves within the bile duct toward the duodenal papilla, thereby pushing foreign bodies within the bile duct out of the bile duct with the distal end of the balloon.

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