JP7616062B2 - Balloon catheter for foreign body removal - Google Patents

Description

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

For example, a method using a balloon catheter for removing foreign bodies is known as a method for removing gallstones that have formed 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 using 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 referred to as the ERCP (endoscopic retrograde cholangiopancreatography) approach.

In the endoscopic gallstone removal technique using the ERCP approach, as shown in Fig. 8, the tip of the endoscope 900 is placed near the duodenal papilla 940, which is the entrance of the bile duct 930, and the catheter tube 902 of the 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, the 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 (in the direction of the arrow in Fig. 9), so that the 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.

JP 2019-10297 A

However, in cases such as duodenal stenosis, it may not be possible to insert a balloon catheter from the duodenal papilla into the bile duct, making the ERCP approach difficult.

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 when approaching via commonly used routes such as the ERCP approach is difficult.

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 a simple and convenient balloon catheter for removing foreign bodies to be realized 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 an approach using a commonly used route such as the ERCP approach is difficult.

The balloon catheter for removing foreign bodies according to the present invention has a tapered distal end of the catheter tube, which improves the guidewire tracking ability and dilation (expansion) performance of the body tissue. This allows the distal end of the balloon catheter for removing foreign bodies to easily and quickly place the balloon at the target site through a puncture hole provided in the body tissue, such as the stomach wall or bile duct wall.

In the balloon catheter for removing foreign bodies according to the present invention, a reinforcing tube that improves the rigidity of the catheter tube is inserted into the guidewire lumen, 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 toward the distal end. This ensures that the pushing force acting at the proximal end is transmitted all the way to the distal end, making it possible to move the balloon toward the distal end with the desired force.

The balloon catheter for removing foreign bodies according to the present invention is designed so that the distal end of the catheter tube can be positioned offset from the center of the balloon by expanding the balloon eccentrically relative to the axis of the catheter tube. This makes it difficult for the 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.

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 a larger outer diameter than the thin-diameter section, and the reinforcing tube is inserted into the thick-diameter section. This makes 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.

The balloon catheter for removing foreign bodies according to the present invention is also characterized in that the reinforcing tube is made of polyether ether ketone. This makes it possible to improve the rigidity of the catheter tube with a simple configuration in which a reinforcing tube made of polyether ether ketone is inserted into the guidewire lumen.

The balloon catheter for removing foreign bodies according to the present invention is characterized in that, with the balloon inflated, the catheter tube is pushed from the proximal end to the distal end, 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 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 to place a balloon in the bile duct through a puncture hole provided in body tissue such as the stomach wall or bile duct wall, and push foreign bodies such as gallstones formed in the bile duct out of the bile duct, even when the ERCP approach is difficult.

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. FIG. 2 is an enlarged side view of the vicinity of region X in FIG. 1 . 2 is a cross-sectional view showing a cross section taken along line AA in FIG. 1. FIG. 2 is a schematic axial cross-sectional view of the vicinity of region Y in FIG. 2 is a schematic axial cross-sectional view of the vicinity of region Z in FIG. 1 . 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. 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. 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. 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. FIG. 9 is an enlarged view of the duodenal papilla and the vicinity of the bile duct in FIG. 8 .

Below, an embodiment of the present invention is explained with reference to the drawings.

Figure 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 Figure 1 is used, for example, via an endoscope, and is configured to include a catheter tube 200, a balloon 300, a branching section 400, and three branch tubes 500a to 500c.

In the following description, the extension direction of the balloon catheter 100 for removing foreign bodies is defined as the axial direction, the balloon 300 side of the balloon catheter 100 for removing foreign bodies is defined as the distal end side, and the three branch tubes 500a to 500c side of the balloon catheter 100 for removing foreign bodies is defined as the proximal end side.

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 a long shape in the axial direction.

The catheter tube 200 has a thin-diameter section 210 at the distal end side where it is inserted into the body via an endoscope, and a thick-diameter section 215 at the proximal end side of the thin-diameter section 210. The total length of the catheter tube 200 is, for example, 500 to 2500 mm, and the axial dimension of the thin-diameter section 210 is 30 to 800 mm. The outer diameter of the thin-diameter section 210 is 50 to 95% of the outer diameter of the thick-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, thermoplastic resin or thermoplastic elastomer is suitable, and for example, polyamide resin or polyamide-based elastomer can be used.

One or more contrast rings 250 are attached to the narrow-diameter portion 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 mounting 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 this makes it possible to confirm the position of the balloon 300. The contrast rings 250 can be made of metals such as gold, platinum, and tungsten.

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

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 that tapers from the most distal end to an axial dimension L1, for example, 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 axial dimension L1 of tapered portion 211 is not particularly limited, but is, for example, 0.5 to 20 mm. Furthermore, tapered portion 211 may be tapered to a point, and there are no particular limitations on the inclination angle of tapered portion 211 or the outer diameter of the most distal end.

The method of 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. In addition, the most distal end of the catheter tube 200 may be formed in a tapered shape by molding a member including the tapered portion 211 and joining the manufactured member to the distal end of the catheter tube 200.

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

The balloon lumen 220 is a lumen used as a flow path for sending a fluid such as air into the inside of the balloon 300 to expand and contract the balloon 300. The balloon lumen 220 penetrates from the proximal end of the catheter tube 200 to a fluid flow port (not shown). The fluid flow port is an opening provided in the narrow diameter portion 210 of the catheter tube 200 that opens into the inside of the balloon 300. As described below, the balloon lumen 220 is also connected to a branch pipe 500a at the branch portion 400.

The guidewire lumen 230 is a lumen used as a path for inserting the guidewire 235. The guidewire lumen 230 penetrates from the proximal end of the catheter tube 200 to the 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 described below, the guidewire lumen 230 is also connected to the branch tube 500b at the bifurcation 400.

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

The cross-sectional shapes of balloon lumen 220, guidewire lumen 230, and contrast agent lumen 240 may be any shape that can be efficiently arranged within catheter tube 200, but since a reinforcing tube 216 is inserted into guidewire lumen 230 and a guidewire 235 inserted into reinforcing tube 216 generally has a circular cross-sectional shape, it is preferable that the cross-sectional shape of guidewire lumen 230 is approximately circular. In addition, the cross-sectional areas of balloon lumen 220, guidewire lumen 230, and contrast agent lumen 240 are not particularly limited, but it is preferable that the cross-sectional area of guidewire lumen 230 be set relatively larger than the cross-sectional areas of balloon lumen 220 and contrast agent lumen 240; for example, the cross-sectional area of balloon lumen 220 is 0.03 to 1.0 mm ² , the cross-sectional area of guidewire lumen 230 is 0.5 to 6.0 mm ² , and the cross-sectional area of contrast agent lumen 240 is 0.08 to 4.0 mm ² .

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 portion 215, i.e., over the range from the proximal end to the distal end of the large diameter portion 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.

The reinforcing tube 216 is preferably a tube with 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 size that allows the reinforcing tube 216 to be inserted in close contact with the inner 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 size that allows the guidewire 235 to be inserted. The material of the reinforcing tube 216 is not particularly limited, but thermoplastic resins are suitable from the viewpoint of moldability and rigidity, and polyether ether ketone (PEEK), which has high rigidity, is particularly preferred.

With reference to Figures 3 to 5, the reinforcing tube 216 inserted into the guidewire lumen 230 will be described.

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

Note that the cross-sectional view of the catheter tube 200 in Figure 3 is an example, and the cross-sectional shape of each of the lumens 220-240 is not limited to the shape shown in Figure 3. Although a three-lumen type catheter tube is illustrated as an example in Figure 3, a two-lumen type catheter tube having two lumens used as, for example, the balloon lumen 220 and the guidewire lumen 230 may also be used. Also, here, the reinforcing tube 216 is inserted only into the guidewire lumen 230, but the reinforcing tube 216 may also be inserted into one or both of the balloon lumen 220 and the contrast medium lumen 240.

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

As shown in FIG. 4, the thin-diameter section 210 and the thick-diameter section 215 each have three lumens formed therein: a balloon lumen 220, a guidewire lumen 230, and a contrast agent lumen 240. The lumens 220-240 inside the thin-diameter section 210 communicate with the lumens 220-240 inside the thick-diameter section 215. The outer diameter of the thin-diameter section 210 is smaller than the outer diameter of the thick-diameter section 215, and the cross-sectional area of each of the lumens 220-240 inside the thin-diameter section 210 is also smaller than the cross-sectional area of each of the lumens 220-240 inside the thick-diameter section 215. The reinforcing tube 216 is inserted into the guidewire lumen 230 inside the thick-diameter section 215, and the distal end of the reinforcing tube 216 is located near the distal end of the thick-diameter section 215 and near the boundary between the thin-diameter section 210 and the thick-diameter section 215. The reinforcing tube 216 has, for example, an outer diameter that is approximately the same as or slightly smaller than the inner diameter of the large diameter portion 215 and is larger than the inner diameter of the small diameter portion 210, so that it can be inserted into the large diameter portion 215 but cannot be inserted into the small diameter portion 210.

Figure 5 is a schematic axial cross-sectional view of the vicinity of region Z in Figure 1. Figure 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 the state in which three lumens, the balloon lumen 220, the guidewire lumen 230, and the contrast agent lumen 240, are provided inside the catheter tube 200. Note that the capacitance tag 700 illustrated in Figure 1 is omitted in Figure 5.

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

4 and 5, the reinforcing tube 216 is inserted into the guidewire lumen 230 from near the boundary between the thin diameter section 210 and the thick diameter section 215 to near the boundary between the thick diameter section 215 and the branch tube 500b, i.e., over the entire thick diameter section 215. There is no particular limitation on the method of inserting the reinforcing tube 216 into the thick diameter section 215 of the catheter tube 200, but for example, it is possible to insert the reinforcing tube 216 into the thick diameter section 215 before connecting the guidewire lumen 230 of the catheter tube 200 to the branch tube 500c.

Specifically, a catheter tube 200 having a thin-diameter portion 210 at the distal end and a thick-diameter portion 215 at the proximal end is prepared, and a reinforcing tube 216 is inserted into the guidewire lumen 230 that opens to the proximal end face of the thick-diameter portion 215 at the proximal end, and the reinforcing tube 216 is pushed toward the distal end. When the distal end of the pushed-in reinforcing tube 216 reaches the vicinity of the boundary between the thin-diameter portion 210 and the thick-diameter portion 215, it cannot enter the thin-diameter portion 210, which has a small cross-sectional area, and is in a state of abutting against the distal end of the thin-diameter portion 210. In this state, the reinforcing tube 216 protruding from the proximal end face of the thick-diameter portion 215 is cut to match the proximal end face of the thick-diameter portion 215, thereby realizing a state in which the reinforcing tube 216 is inserted into the guidewire lumen 230 over the entire thick-diameter portion 215. In the embodiment of the present invention, the reinforcing tube 216 is prevented from slipping out of the guidewire lumen 230 by connecting a branch tube 500b to the reinforcing tube 216 as described below, and therefore 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.

The balloon 300 is a cylindrical thin film that can be expanded by introducing a fluid into the balloon 300, 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 into the balloon 300 through the balloon lumen 220 and the fluid outlet port of the catheter tube 200. In an embodiment of the present invention, it is possible to remove foreign bodies from the body by pushing out foreign bodies such as gallstones with the distal end side of the inflated balloon 300.

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 more preferably 1 to 5 MPa. Specific examples of elastic materials suitable for forming the balloon 300 include natural rubber, silicone rubber, and polyurethane elastomer.

The balloon 300 is generally cylindrical, and has joints 310, 320 formed at the distal and proximal ends to be joined to the outer circumferential surface of the catheter tube 200. The joints 310, 320 refer to the portions where the balloon 300 is joined to the outer circumferential surface of the catheter tube 200 in a cylindrical shape, and the axial dimensions of the joints 310, 320 are, for example, 0.5 to 5.0 mm. The method for joining the joints 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.

Between the joints 310 and 320 of the balloon 300, an expansion section 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 section 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 section 330 is, for example, 5 to 20 mm, and the membrane thickness is, for example, 0.10 to 0.50 mm.

In addition, an offset sheet 340 is attached to a part of the expansion section 330 so that the expansion section 330 expands eccentrically relative to the axis 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.

Because 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 that is eccentric with respect to the axis of the catheter tube 200.

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 side 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 of the width. 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.

In the embodiment of the present invention, the balloon 300 is inflated into a shape that is eccentric with respect to the axis of the catheter tube 200 by attaching the offset sheet 340. However, the balloon 300 may be made to inflate 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 portion of the outer peripheral surface of the catheter tube 200.

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

The branch tube 500a is a balloon branch tube, and a balloon hub 600a equipped with, for example, a two-way stopcock is connected to the proximal end of the branch tube 500a. The balloon hub 600a and the branch tube 500a are connected to 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 tube 500a, the balloon lumen 220, and the fluid flow port.

The 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 the branch tube 500b. The guidewire hub 600b and the branch tube 500b are connected to the inner cavity of the reinforcing tube 216 inserted into the guidewire lumen 230 at the bifurcation 400, and the guidewire 235 can be protruded from the guidewire hub 600b to the outside through the branch tube 500b, the reinforcing tube 216, the guidewire lumen 230, and the guidewire insertion hole 231 provided at the most distal end of the catheter tube 200.

The branch tube 500c is a branch tube for contrast imaging, and a lure-lock type hub for contrast imaging 600c is connected to the proximal end of the branch tube 500c. The hub for contrast imaging 600c and the branch tube 500c are connected to the contrast medium lumen 240 at the branching portion 400, so that the contrast medium can be ejected from the hub for contrast imaging 600c to the outside through the branch tube 500c, the contrast medium lumen 240, and the contrast medium outlet.

A capacitance tag 700 is attached to the outer periphery of the catheter tube 200 on the distal end side of the branching section 400. The capacitance tag 700 contains 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.

As described above, the balloon catheter 100 for removing foreign bodies in the embodiment of the present invention has a first characteristic in that a tapered portion 211 is formed at the distal end of the catheter tube 200, a second characteristic in that a reinforcing tube 216 for improving the rigidity of the catheter tube 200 is inserted into the guidewire lumen 230, and a third characteristic in that the balloon 300 is configured to inflate eccentrically relative to the axis of the catheter tube 200.

Focusing on the above-mentioned first to third features, an example of use of the balloon catheter 100 for removing foreign bodies according to an 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 patient's stomach wall and intrahepatic bile duct wall (liver) and the balloon catheter 100 for removing foreign bodies is inserted into the bile duct through the puncture holes in a case where it has been confirmed that the ERCP approach is difficult due to circumstances such as the occurrence of stenosis in the patient's duodenum.

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, the tip of an ultrasonic endoscope 800 is inserted into the body, and an intrahepatic bile duct 820 is depicted as an ultrasonic image from the stomach 810 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. After that, 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).

Next, with the balloon 300 placed in the bile duct 830, a contrast agent is sprayed, and the state of the inside of the bile duct 830 and the gallstones 850 is confirmed by X-ray contrast images, after which the balloon 300 is inflated. Then, by pushing the proximal end of the catheter tube 200 toward the distal end (in 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 (in the direction of the arrow in FIG. 6), and the distal end side of the inflated balloon 300 pushes the gallstones 850 out of the bile duct 830 from the duodenal papilla 840, thereby removing them.

As described above, the balloon catheter 100 for removing foreign bodies according to 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 the body lumen 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.

In contrast, in the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, the most distal end of the catheter tube 200 is tapered, so that the most distal end of the catheter tube 200 can proceed while expanding the path without damaging internal body tissue such as the wall surrounding the puncture hole. That is, the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention has a first feature in which the most distal end of the catheter tube 200 is tapered, and thus realizes a configuration that improves guidewire tracking ability and dilation performance when proceeding along the guidewire 235.

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 in which a balloon catheter is inserted 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 and 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 of the balloon 300. However, in conventional balloon catheters, 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 of the balloon.

In contrast, in the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, a reinforcing tube 216 for improving the rigidity of the catheter tube 200 is inserted into the guidewire lumen 230, and 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, so that the balloon 300 can be moved toward the distal end with the desired force. That is, the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention has a second feature in which a reinforcing tube 216 for improving 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.

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 of the inflated balloon 300, unlike the conventional ERCP approach in which the gallstones are scraped out by the proximal end of the balloon. However, when using a conventional balloon catheter to push out gallstones present at the distal end 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 able to be moved toward the distal end, and the gallstones may not be able to be pushed out of the bile duct at the distal end of the balloon.

In contrast, in the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, the balloon 300 expands eccentrically with respect to the axis of the catheter tube 200, so that the most distal end of the catheter tube 200 can be positioned at a position offset from the center of the balloon 300. That is, in the balloon catheter 100 for removing foreign bodies according to the embodiment of the present invention, due to the third feature that the balloon 300 expands eccentrically with respect to the axis of the catheter tube 200, the most distal end of the catheter tube 200 can be positioned 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.

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 positioned 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 positioned at a position offset from the axis of the catheter tube 200.

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 (in the direction of the arrow in FIG. 7A) with the distal end of the catheter tube 200, on which 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 be moved toward the distal end, making it impossible to push out the gallstone 850 at the distal end of the balloon 300.

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 most distal end of the catheter tube 200, where the tapered portion 211 is formed, positioned to the side of the moving direction of the balloon 300. In this case, the most distal end of the catheter tube 200 does not hit the gallstone 850, and the distal end side of the balloon 300 can be successfully pressed against the gallstone 850, and the gallstone 850 can be reliably pushed out by the distal end side of the balloon 300.

The above-described embodiments 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 embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

For example, in the above-mentioned embodiment, the balloon catheter 100 for removing foreign bodies is inserted through a puncture hole in the stomach wall and the intrahepatic bile duct wall (liver) of a patient, and used to expel (remove) foreign bodies such as gallstones from the bile duct by inserting the balloon catheter 100 from the intrahepatic bile duct into the bile duct through the puncture hole. However, 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 provided in body tissue in cases where an approach via a commonly used route such as the ERCP approach is difficult.

100 Balloon catheter for removing foreign bodies 200, 902 Catheter tube 210 Thin section 211 Tapered section 215 Thick section 216 Reinforcing tube 220 Balloon lumen 230 Guidewire lumen 231 Guidewire insertion hole 235 Guidewire 240 Contrast medium lumen 250 Contrast ring 300 Balloon 310, 320 Joint 330 Expansion section 340 Offset sheet 400 Branch section 500a to 500c Branch duct 600a Balloon hub 600b Guidewire hub 600c Contrast hub 700 Capacitor tag 800, 900 Endoscope 810 Stomach 820 Intrahepatic bile duct 830, 930 Bile duct 840, 940 Duodenal papilla 850, 950 Gallstones

Claims (3)

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