Bile suction catheter

Abstract

To provide a bile aspiration catheter capable of optimally aspirating and removing bile accumulated in the depth of a bile duct.SOLUTION: A catheter 1 for being inserted into a bile duct to aspirate bile, comprises a shaft 2 extending in a longitudinal direction from a proximal side to a distal side, a first lumen 4 provided in the shaft 2, extending in the longitudinal direction, and having a liquid discharge port 5 at the distal end, and a second lumen 7 provided in the shaft 2, extending in the longitudinal direction, and having a liquid aspiration port 8 at the distal end. The liquid discharge port 5 is located 3 mm or more and 10 mm or less distal to the liquid aspiration port 8, and the shaft 2 has an outer diameter within a range of at least 250 mm or less from the distal end to the proximal side, of 4.0 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bile aspiration catheter. [Background technology]

[0002] When the bile duct is blocked by gallstones or tumors, or when bile flow is obstructed within the bile duct, bile can stagnate within the bile duct, causing bacterial infection. Bacterial infection of the bile can lead to cholangitis, and if the bacteria-containing bile passes through the liver and enters the bloodstream, it can cause sepsis. In such cases, procedures to drain bile from the bile duct are necessary, and methods such as percutaneous transhepatic biliary drainage (PTCD) and endoscopic biliary drainage (ERBD) are performed.

[0003] As an example of a catheter that is inserted into a bile duct, Patent Document 1 discloses a bile duct drainage catheter that includes a catheter tube whose distal end is inserted into the bile duct. The catheter tube has a main body that has a substantially constant outer diameter along the longitudinal direction, a first tapered section that continues to the distal end of the main body and whose outer diameter tapers toward the distal end, a thin straight body section that continues to the distal end of the first tapered section and has a substantially constant outer diameter along the longitudinal direction, and a second tapered section that continues to the distal end of the thin straight body section and whose outer diameter tapers toward the distal end, the thin straight body section having an outer diameter that is 20 to 80% of the outer diameter of the main body and a length of 30 to 250 mm. Patent Document 2 discloses an elongated medical member that includes a long insertion section provided with multiple lumens through which working treatment tools for performing a predetermined medical procedure can be inserted, and a guide section that extends from the tip of the insertion section and guides the insertion section, with an opening formed on the tip surface of the guide section, and fluid supply lumens formed in the insertion section and the guide section. Patent Document 2 also describes that bile in the bile duct may be aspirated from the opening at the tip of the insertion section. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-329314 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-251140 Summary of the Invention [Problem to be solved by the invention]

[0005] When aspirating bile from the bile duct using a catheter, it is desirable to be able to aspirate not only the bile from the common bile duct at the entrance of the bile duct but also from the intrahepatic bile duct deep inside the bile duct, thereby reducing the amount of bile left behind in the bile duct. The present invention has been made in view of the above circumstances, and its object is to provide a bile aspirating catheter that can suitably aspirate and remove bile that has accumulated deep inside the bile duct. [Means for solving the problem]

[0006] The bile aspiration catheter of the present invention, which has been able to solve the above-mentioned problems, is a catheter for insertion into a bile duct to aspirate bile, and is characterized in that it has a shaft extending longitudinally from the proximal side to the distal side, a first lumen provided in the shaft, extending longitudinally, and having a liquid discharge port at its distal end, and a second lumen provided in the shaft, extending longitudinally, and having a liquid suction port at its distal end, the liquid discharge port being located 3 mm to 10 mm distal to the liquid suction port, and the shaft has an outer diameter of 4.0 mm or less within a range of at least 250 mm proximal to the distal end.

[0007] The bile aspiration catheter of the present invention has a narrow outer diameter of 4.0 mm or less at the distal shaft portion inserted into the bile duct, allowing it to be inserted deep into the bile duct, for example, through the common bile duct and into the intrahepatic bile duct. After the distal shaft portion is inserted into the bile duct, bile accumulated in the bile duct can be diluted by discharging a cleaning liquid into the bile duct from the liquid outlet. This reduces the viscosity of bile accumulated in the bile duct, making it easier to aspirate the bile through the liquid suction port. Furthermore, by positioning the liquid outlet 3 mm to 10 mm distal to the liquid suction port, deliverability can be improved, facilitating cleaning deeper into the bile duct and facilitating aspirating bile accumulated deep within the bile duct, thereby reducing the amount of bile left behind. For example, if the liquid outlet and liquid suction port were located at the same longitudinal position, the outer diameter of the shaft would be large, potentially reducing deliverability. However, by positioning the liquid outlet 3 mm or more distal to the liquid suction port, the shaft can be easily inserted deeper into the bile duct. On the other hand, if the liquid discharge port and the liquid suction port are positioned apart in the longitudinal direction, undiluted bile will be aspirated rather than the diluted bile near the liquid discharge port, reducing the efficiency of aspirating. However, by positioning the liquid discharge port 3 to 10 mm distal to the liquid suction port, bile diluted with the cleaning fluid from the liquid discharge port can be efficiently aspirated. Furthermore, by positioning the liquid discharge port 10 mm or less distal to the liquid suction port, the length of the portion distal to the liquid suction port does not become too long, making it easier to ensure the rigidity of the distal end of the shaft and improving deliverability.

[0008] The shaft preferably has a first section having a predetermined length proximal to the liquid suction port and a second section proximal to the first section, and the outer diameter of the shaft in the second section is larger than the outer diameter of the shaft in the first section. This configuration of the shaft facilitates insertion of the shaft deep into the bile duct. That is, the shaft having the second section increases the rigidity of the shaft in this section, improving the deliverability of the catheter. Meanwhile, the shaft having the first section facilitates insertion of the shaft into the intrahepatic bile duct, which has a narrow internal space.

[0009] It is preferable that the inner diameter of the first lumen in the second section is larger than the inner diameter of the first lumen in the first section, and the inner diameter of the second lumen in the second section is larger than the inner diameter of the second lumen in the first section. This ensures the deliverability of the distal section of the shaft inserted into the bile duct, while increasing the inner diameters of the proximal sections of the first lumen and second lumen allows for more effective ejection of the cleaning solution and aspirating of bile.

[0010] In this case, the length of the first section is preferably 50 mm or more and 200 mm or less, and the outer diameter of the shaft in the first section is preferably 2.5 mm or less.

[0011] In a cross section perpendicular to the longitudinal direction of the shaft, the cross-sectional area of ​​the second lumen is preferably larger than that of the first lumen. This makes it less likely that gallstones or the like will clog the second lumen when aspirating bile. It also makes it easier to forcefully eject the cleaning liquid from the liquid outlet of the first lumen, making it easier to clean deeper inside the bile duct.

[0012] The outer edge of the liquid suction port preferably has a sloped portion, and the distal end of the sloped portion is preferably located closer to the first lumen than the proximal end of the sloped portion. If the liquid suction port is formed in this manner, the size of the liquid suction port can be made larger, making it easier to suction bile.

[0013] The shaft preferably has a tapered portion distal to the liquid suction port, the outer diameter of which decreases toward the distal end, making it easier to insert the shaft into a bile duct, particularly an intrahepatic bile duct.

[0014] The liquid discharged from the liquid discharge port is preferably physiological saline. Also, the first lumen preferably doubles as a guidewire lumen.

[0015] The bile aspiration catheter of the present invention can be suitably used by being inserted into the intrahepatic bile duct, and is therefore effective as a bile aspiration catheter for the intrahepatic bile duct. [Effects of the Invention]

[0016] The bile aspiration catheter of the present invention can be inserted deep into the bile duct, for example, through the common bile duct to the intrahepatic bile duct. This facilitates flushing deeper into the bile duct and also makes it easier to aspirate bile that has accumulated deep inside the bile duct, thereby reducing the amount of bile left behind. [Brief explanation of the drawings]

[0017] [Figure 1] 1 shows an example of a bile aspiration catheter according to an embodiment of the present invention, and is an overall side view of the bile aspiration catheter. [Figure 2] FIG. 2 illustrates a side view of the distal portion of the bile aspiration catheter shown in FIG. 1. [Figure 3] 2 illustrates a perspective view of the distal end of the bile aspiration catheter shown in FIG. 1. [Figure 4] 3 shows a longitudinal cross-sectional view of the distal end of the bile aspiration catheter shown in FIG. 2. [Figure 5] FIG. 2 shows a VV cross-sectional view of the bile suction catheter shown in FIG. 1. [Figure 6] 3 illustrates a variation of a side view of the distal portion of the bile aspiration catheter shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0018] The bile suction catheter of the present invention will be specifically described below based on the following embodiments, but the present invention is not limited to the following embodiments and can be modified appropriately within the scope of the above and below-described purposes, and all such modifications are within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, reference should be made to the specification and other drawings. The dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to helping understand the features of the present invention.

[0019] A bile aspiration catheter according to an embodiment of the present invention will be described with reference to Figures 1 to 6. Figure 1 shows an example of a bile aspiration catheter according to an embodiment of the present invention, and is an overall side view of the bile aspiration catheter, Figure 2 shows a side view of the distal portion of the bile aspiration catheter shown in Figure 1, Figure 3 shows a perspective view of the distal end portion of the bile aspiration catheter shown in Figure 1, Figure 4 shows a longitudinal cross-sectional view of the distal end portion of the bile aspiration catheter shown in Figure 2, Figure 5 shows a VV cross-sectional view of the bile aspiration catheter shown in Figure 1, and Figure 6 shows a modified side view of the distal portion of the bile aspiration catheter shown in Figure 2.

[0020] The bile aspiration catheter 1 is a catheter used for inserting into the bile duct and aspirating bile. The bile aspiration catheter 1 of the present invention is capable of aspirating bile accumulated in the bile duct while supplying a liquid into the bile duct to clean the inside of the bile duct, and is particularly suitable for use by inserting into the intrahepatic bile duct, which is located in a deep part of the bile duct. Hereinafter, the bile aspiration catheter will be simply referred to as a "catheter."

[0021] The catheter 1 has a shaft 2 extending in the longitudinal direction. In the catheter 1, the longitudinal direction is determined based on the extension direction of the shaft 2. The catheter 1 has a proximal side and a distal side as one side and the other side of the longitudinal direction. The proximal side refers to the direction toward the user of the catheter 1, i.e., the operator's hand, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. The shaft 2 has a radial direction that is perpendicular to the longitudinal direction. In Figure 1, the right side of the figure corresponds to the proximal side, and the left side of the figure corresponds to the distal side.

[0022] The shaft 2 has a first lumen 4 with a liquid outlet 5 at its distal end and a second lumen 7 with a liquid suction port 8 at its distal end. The first lumen 4 and the second lumen 7 each extend longitudinally and are arranged radially side by side. The shaft 2 has a first tube 3 and a second tube 6, with the inner lumen of the first tube 3 serving as the first lumen 4 and the inner lumen of the second tube 6 serving as the second lumen 7. The first tube 3 and the second tube 6 are arranged side by side, with the liquid outlet 5 formed at the distal end of the first tube 3 and the liquid suction port 8 formed at the distal end of the second tube 6. The first tube 3 and the second tube 6 are preferably integrated by welding or bonding to each other, or the first tube 3 and the second tube 6 are preferably arranged within the lumen of a protective tube 9, which integrates the first tube 3 and the second tube 6. Although not shown in the drawings, two lumens may be formed in a single tube to serve as the first and second lumens.

[0023] When the catheter 1 is in use, a liquid (cleansing liquid) to be supplied into the bile duct flows through the first lumen 4 of the first tube 3, and the liquid is discharged into the bile duct from the liquid discharge port 5 at the distal end of the first tube 3. Therefore, it is preferable that the first tube 3 has a proximal opening, and that a liquid supply unit be provided in communication with the proximal opening of the first tube 3. Examples of the liquid supply unit include a syringe and a pump.

[0024] Bile and other fluids accumulated in the bile duct are sucked through the liquid suction port 8 at the distal end of the second tube 6 and discharged from the bile duct through the second lumen 7 of the second tube 6. Therefore, the second tube 6 preferably has a proximal opening, and a liquid suction unit is provided in communication with the proximal opening of the second tube 6. Examples of the liquid suction unit include a syringe and a pump. A backlock syringe may be used as the syringe of the liquid suction unit.

[0025] The first lumen 4 can also serve as a guidewire lumen. By having the first lumen 4 also serve as a guidewire lumen, the outer diameter of the shaft 2 can be reduced. In addition, it is possible to aspirate bile and wash the inside of the bile duct without removing the guidewire, which simplifies the procedure and shortens the surgical time.

[0026] A hub 10 is preferably provided on the proximal side of the shaft 2. The hub 10 has a supply connection port 11 communicating with the first lumen 4 and a suction connection port 12 communicating with the second lumen 7, and it is preferable that a liquid supply unit be connected to the supply connection port 11 of the hub 10 and a liquid suction unit be connected to the suction connection port 12 of the hub 10. By providing the hub 10, the operability of the catheter 1 can be improved.

[0027] Preferably, the hub 10 further includes a guidewire port 13. The guidewire port 13 is preferably provided in communication with the first lumen 4. In this case, inside the hub 10, the internal passage communicating with the first lumen 4 branches into two, one of which connects to the supply connection port 11 and the other to the guidewire port 13.

[0028] The hub 10 may further have an auxiliary port through which another medical tool can be inserted. The auxiliary port can be provided, for example, in communication with the second lumen 7. In this case, inside the hub 10, the internal passage communicating with the second lumen 7 branches into two, one of which connects to the suction connection port 12 and the other to the auxiliary port. An example of another medical tool is a brush for cytology, which can be used to collect a specimen for cytology following bile aspiration.

[0029] A check valve may be provided in the internal passage of the hub 10. For example, by providing a check valve in the internal passage connecting the first lumen 4 and the supply connection port 11 of the hub 10, liquid can flow in one direction, from the supply connection port 11 to the first lumen 4. By providing a check valve in the internal passage connecting the second lumen 7 and the suction connection port 12 of the hub 10, liquid can flow in one direction, from the second lumen 7 to the suction connection port 12.

[0030] Although not shown in the drawings, a first hub connected to the first lumen 4 and a second hub connected to the second lumen 7 may be provided on the proximal side of the shaft 2. The first hub and / or the second hub may have an internal passage branched into two or more branches, with two or more ports communicating with each of the internal passages. For example, the first hub connected to the first lumen 4 may have a supply connection port 11 and may also have a guidewire port 13. The second hub connected to the second lumen 7 may have a suction connection port 12 and may also have the auxiliary port described above. A check valve may be provided in the internal passage of the first hub and / or the second hub.

[0031] The longitudinal length of the shaft 2 is, for example, preferably 1500 mm or more, more preferably 1800 mm or more, and preferably 3000 mm or less, and more preferably 2800 mm or less. The inner diameters of the first lumen 4 and the second lumen 7 are, for example, preferably 0.5 mm or more, more preferably 0.7 mm or more, even more preferably 0.9 mm or more, and preferably 2.5 mm or less, more preferably 2.2 mm or less, and even more preferably 2.0 mm or less.

[0032] In a cross section perpendicular to the longitudinal direction of the shaft 2, the shapes of the outer edge of the shaft 2, the outer edge of the first tube 3, the outer edge of the second tube 6, the first lumen 4, and the second lumen 7 are not particularly limited, and examples thereof include circular, elliptical, oval, egg-shaped, polygonal, irregular, etc. Preferably, the shapes of the outer edge of the shaft 2, the outer edge of the first tube 3, the outer edge of the second tube 6, the first lumen 4, and the second lumen 7 are circular, oval, elliptical, or egg-shaped.

[0033] The first tube 3, second tube 6, and protective tube 9 that constitute the shaft 2 can be made of resin. Examples of resin include synthetic resins such as polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as polyethylene terephthalate, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, polyamide imide resins, fluorine-based resins such as PTFE, PFA, and ETFE, polyvinyl chloride resins, and silicone resins.

[0034] The shaft 2, the first tube 3, the second tube 6, and the protective tube 9 may be made of a single layer or multiple layers. The shaft 2, the first tube 3, the second tube 6, and the protective tube 9 may have a portion in the longitudinal direction made of a single layer and another portion made of multiple layers.

[0035] The shaft 2, the first tube 3, the second tube 6, and the protective tube 9 may have a reinforcing layer. The reinforcing layer can increase the rigidity of the shaft 2. The reinforcing layer is preferably disposed between an inner layer and an outer layer made of resin.

[0036] The reinforcing layer can be made of metal wires, fibers, etc. Examples of materials for making metal wires include stainless steel, titanium, nickel-titanium alloys, cobalt-chromium alloys, and tungsten alloys. Of these, stainless steel is preferred. The metal wires may be solid or twisted. Examples of fibers include polyarylate fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, PBO fibers, and carbon fibers. The fibers may be monofilaments or multifilaments.

[0037] The shape of the reinforcing layer is not particularly limited, but is preferably spiral, mesh, or braided. Of these, the reinforcing layer is more preferably braided because the reinforcing layer can effectively increase the rigidity of the shaft 2.

[0038] The shaft 2 is configured so that the liquid discharge port 5 is located distal to the liquid suction port 8. This allows the liquid discharge port 5 to be located at the tip of the shaft 2, making it easier to insert the device deeper into the bile duct for cleaning and suction. Because the liquid discharge port 5 is formed at the distal end of the first lumen 4, the cleaning liquid transported through the first lumen 4 to the distal end of the first lumen 4 is discharged distally from the liquid discharge port 5, making it possible to clean the inside of the bile duct distal to the liquid discharge port 5. Furthermore, bile has a relatively high viscosity, and bacterially infected bile has even higher viscosity. However, by discharging the cleaning liquid into the bile duct from the liquid discharge port 5, the bile accumulated in the bile duct is diluted and its viscosity is reduced. Meanwhile, the liquid suction port 8 is located proximal to the liquid discharge port 5, making it easier to suction bile accumulated in the bile duct. In other words, because the liquid suction port 8 is located proximal to the liquid discharge port 5, bile whose viscosity has been reduced due to dilution with the cleaning liquid can be more easily suctioned through the liquid suction port 8. This makes it easier to suck bile through the liquid suction port 8, and also makes it less likely that the sucked bile will clog the second lumen 7.

[0039] The liquid discharge port 5 is located 3 mm to 10 mm distal to the liquid suction port 8. Positioning the liquid discharge port 5 and the liquid suction port 8 in this manner improves the deliverability of the catheter 1, making it easier to clean deeper into the bile duct and to aspirate bile that has accumulated deep inside the bile duct, thereby reducing the amount of bile left behind. For example, if the liquid discharge port 5 and the liquid suction port 8 were located at the same longitudinal position, the outer diameter of the shaft 2 would increase, potentially reducing deliverability. However, by positioning the liquid discharge port 5 3 mm or more distal to the liquid suction port 8, the shaft 2 can be easily inserted deeper into the bile duct. On the other hand, if the liquid discharge port 5 and the liquid suction port 8 were located farther apart from each other in the longitudinal direction, undiluted bile would be aspirated instead of the diluted bile near the liquid discharge port 8, reducing suction efficiency. However, by positioning the liquid discharge port 5 at least 3 mm but not more than 10 mm distal to the liquid suction port 8, the suction of undiluted bile is suppressed, and bile diluted with a cleaning solution is more easily suctioned. Furthermore, by positioning the liquid discharge port 5 at least 10 mm distal to the liquid suction port 8, the length of the portion of the distal end of the shaft 2 distal to the liquid suction port 8 (i.e., the length of the portion where the first tube 3 is present but the second tube 6 is not) does not become too long, making it easier to ensure the rigidity of the distal end of the shaft 2 and improving the deliverability of the catheter 1. Preferably, the liquid discharge port 5 is positioned at least 4 mm distal to the liquid suction port 8, and is preferably 8 mm or less, more preferably 7 mm or less. The separation distance between the liquid discharge port 5 and the liquid suction port 8 is determined by measuring the longitudinal separation distance between the proximal end of the liquid discharge port 5 and the distal end of the liquid suction port 8.

[0040] The shaft 2 has an outer diameter of 4.0 mm or less within a range of at least 250 mm proximal to the distal end. This configuration of the shaft 2 allows the shaft 2 to be inserted deep into the bile duct, for example, through the common bile duct to the intrahepatic bile duct. Because the intrahepatic bile duct has a narrower internal space than the common bile duct, it is difficult to insert a shaft 2 with an outer diameter of, for example, 5.0 mm deep into the intrahepatic bile duct. However, by forming the outer diameter of the shaft 2 to 4.0 mm or less within a range of at least 250 mm proximal to the distal end of the shaft 2, the shaft 2 can be inserted deep into the intrahepatic bile duct through the common bile duct. The outer diameter of the shaft 2 described here refers to the maximum diameter of the outer edge of the shaft 2 in a vertical cross section taken along the longitudinal direction. In other words, if the shape of the outer edge of the shaft 2 in a vertical cross section taken along the longitudinal direction is circular, this refers to the diameter of the circle. If the shape is non-circular, this refers to the maximum diameter (long diameter).

[0041] The shaft 2 may have an outer diameter of 4.0 mm or less throughout the entire range of at least 250 mm from the distal end proximally, and may also have an outer diameter of 4.0 mm or less in a section more proximal than that. The portion of the shaft 2 where the outer diameter is 4.0 mm or less may be within 300 mm, 500 mm, or 1000 mm from the distal end proximally, or may be substantially the entire longitudinal range of the shaft 2.

[0042] The outer diameter of the shaft 2 within a range of 250 mm proximal to the distal end is preferably 3.5 mm or less, more preferably 3.0 mm or less. This makes it easier to insert the shaft 2 into the intrahepatic bile duct. On the other hand, the lower limit of the outer diameter of the shaft 2 proximal to the proximal end of the liquid suction port 8 is preferably 1.0 mm or more, more preferably 1.3 mm or more, and even more preferably 1.5 mm or more. This improves the deliverability of the catheter 1. Note that the outer diameter of the shaft 2 distal to the liquid suction port 8 is smaller than the outer diameter of the shaft 2 proximal to the liquid suction port 8.

[0043] The shaft 2 preferably has a first section 14 having a predetermined length proximal to the liquid suction port 8 and a second section 15 proximal to the first section 14, and the outer diameter of the shaft 2 in the second section 15 is larger than the outer diameter of the shaft 2 in the first section 14. Configuring the shaft 2 in this manner facilitates insertion of the shaft 2 into the intrahepatic bile duct. That is, the shaft 2 having the second section 15 increases the rigidity of the shaft 2 in the second section 15, thereby improving the deliverability of the catheter 1. On the other hand, the shaft 2 having the first section 14 facilitates insertion of the shaft 2 into the intrahepatic bile duct, which has a narrow internal space.

[0044] The inner diameter of the first lumen 4 in the second section 15 is preferably larger than the inner diameter of the first lumen 4 in the first section 14. Furthermore, the inner diameter of the second lumen 7 in the second section 15 is preferably larger than the inner diameter of the second lumen 7 in the first section 14. This ensures the deliverability of the distal section of the shaft 2 inserted into the bile duct, while increasing the inner diameters of the proximal sections of the first lumen 4 and the second lumen 7 allows for more effective ejection of the cleaning solution and aspirating of bile. While only one of the first lumen 4 and the second lumens 7 may be formed in this manner, it is preferable that both be formed in this manner.

[0045] The first section 14 and the second section 15 are preferably formed within a range of 250 mm proximal to the distal end of the shaft 2, and the second section 15 preferably extends further proximally than this range. Therefore, the outer diameter of the shaft 2 in the first section 14 is preferably 4.0 mm or less, and the outer diameter of the shaft 2 in the second section 15 is also preferably 4.0 mm or less.

[0046] The length of the first section 14 is preferably, for example, 50 mm or more and 200 mm or less. This makes it easier to insert the shaft 2 into the intrahepatic bile duct. The length of the first section 14 is more preferably 70 mm or more, even more preferably 90 mm or more, and more preferably 180 mm or less, and even more preferably 160 mm or less. The length of the second section 15 is preferably 100 mm or more, more preferably 300 mm or more, and even more preferably 500 mm or more. The second section 15 may extend to the proximal portion of the shaft 2.

[0047] The outer diameter of the shaft 2 in the first section 14 is preferably 2.5 mm or less, more preferably 2.4 mm or less, and even more preferably 2.3 mm or less. This makes it easier to insert the first section 14 and the portion distal to it of the shaft 2 into the intrahepatic bile duct. The lower limit of the outer diameter of the shaft 2 in the first section 14 is preferably 1.0 mm or more, more preferably 1.3 mm or more, and even more preferably 1.5 mm or more.

[0048] The outer diameter of the shaft 2 in the second section 15 is preferably 4.0 mm or less, more preferably 3.5 mm or less, even more preferably 3.0 mm or less, and preferably 1.5 mm or more, more preferably 1.8 mm or more, and even more preferably 2.0 mm or more. The outer diameter of the shaft 2 in the second section 15 is also preferably 0.1 mm or more larger than the outer diameter of the shaft 2 in the first section 14, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more, and is preferably 1.0 mm or less, more preferably 0.8 mm or less, and even more preferably 0.6 mm or less.

[0049] The inner diameter of the first lumen 4 in the first section 14 is preferably 1.3 mm or less, more preferably 1.1 mm or less, even more preferably 1.0 mm or less, and preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 0.9 mm or more. The inner diameter of the first lumen 4 in the second section 15 is preferably 0.1 mm or more larger than the inner diameter of the first lumen 4 in the first section 14, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. The inner diameter of the first lumen 4 in the second section 15 is preferably 2.0 mm or less, more preferably 1.8 mm or less, and even more preferably 1.5 mm or less.

[0050] The inner diameter of the second lumen 7 in the first section 14 is preferably 1.0 mm or more, more preferably 1.5 mm or more, and even more preferably 2.0 mm or more. The inner diameter of the second lumen 7 in the second section 15 is preferably 0.1 mm or more larger than the inner diameter of the second lumen 7 in the first section 14, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. The inner diameter of the second lumen 7 in the second section 15 is preferably 1.5 mm or more, more preferably 2.0 mm or more, and even more preferably 2.5 mm or more. The inner diameter of the second lumen 7 in the first section 14 is preferably 0.1 mm or more larger than the inner diameter of the first lumen 4 in the first section 14, more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. The upper limit of the inner diameter of the second lumen 7 in the first section 14 and the second section 15 may be set appropriately depending on the outer diameter of the shaft in the first section 14 and the second section 15.

[0051] The inner and outer diameters of the first lumen 4 and the second lumen 7 described above refer to the equivalent circle diameters if their shapes are other than circular. For example, taking the inner diameter of the first lumen 4 as an example, the equivalent circle diameter is the diameter of a circumference with a length equal to the length of the inner diameter of the first lumen 4.

[0052] To make the outer diameter of the shaft 2 in the second section 15 larger than the outer diameter of the shaft 2 in the first section 14, for example, the following may be used: (1) a protective tube 9 is not provided, and the outer diameter of the first tube 3 is made larger in the second section 15 than in the first section 14; (2) a protective tube 9 is not provided, and the outer diameter of the second tube 6 is made larger in the second section 15 than in the first section 14; (3) a protective tube 9 is not provided, and the outer diameters of the first tube 3 and the second tube 6 are made larger in the second section 15 than in the first section 14; (4) the outer diameter of the protective tube 9 that places the first tube 3 and the second tube 6 in the lumen is made larger in the second section 15 than in the first section 14; (5) a protective tube 9 is not provided in the first section 14, but is provided in the second section 15. In these embodiments, it is preferable that the inner diameter of the first tube 3 (i.e., the inner diameter of the first lumen 4) is larger in the second section 15 than in the first section 14, and it is preferable that the inner diameter of the second tube 6 (i.e., the inner diameter of the second lumen 7) is larger in the second section 15 than in the first section 14. In the drawings, in embodiment (4), the outer diameter of the shaft 2 in the second section 15 is larger than the outer diameter of the shaft 2 in the first section 14.

[0053] When the inner and / or outer diameter of the first tube 3 is larger in the second section 15 than in the first section 14, when the inner and / or outer diameter of the second tube 6 is larger in the second section 15 than in the first section 14, or when the inner and / or outer diameter of the first tube 3 is larger in the second section 15 than in the first section 14 and the inner and / or outer diameter of the second tube 6 is larger in the second section 15 than in the first section 14, the first tube 3 and / or the second tube 6 may be produced by welding or bonding tubes with different inner and / or outer diameters to each other, or by using dies with different inner and / or outer diameters during tube extrusion. At the boundary between the first section 14 and the second section 15, the inner and / or outer diameter of the tube may change in a stepped or tapered manner.

[0054] In a cross section perpendicular to the longitudinal direction of the shaft 2, the cross-sectional area of ​​the second lumen 7 is preferably larger than that of the first lumen 4 (see FIG. 5). This reduces the likelihood of gallstones or the like clogging the second lumen 7 when aspirating bile. Furthermore, this facilitates the forceful discharge of cleaning liquid from the liquid outlet 5 of the first lumen 4, facilitating cleaning deeper within the bile duct. The cross-sectional area of ​​the second lumen 7 is, for example, preferably 1.1 times or more, more preferably 1.2 times or more, and preferably 4.0 times or less, more preferably 3.0 times or less, and even more preferably 2.5 times or less than the cross-sectional area of ​​the first lumen 4. Note that, although FIG. 5 shows gaps between the protective tube 9 and the first tube 3 and second tube 6, gaps do not necessarily have to exist between the protective tube 9 and the first tube 3 and second tube 6. For example, after placing the first tube 3 and the second tube 6 inside the protective tube 9, a heat-shrinkable tube is further placed on the outside and thermally processed, thereby eliminating any gaps between the protective tube 9 and the first tube 3 and second tube 6.

[0055] The liquid suction port 8 is preferably formed in an inclined shape. Specifically, the outer edge of the liquid suction port 8 preferably has an inclined portion, and the distal end of the inclined portion is preferably located closer to the first lumen 4 than the proximal end of the inclined portion. If the liquid suction port 8 is formed in this manner, the size of the liquid suction port 8 can be made larger, making it easier to aspirate bile. Furthermore, by positioning the distal end of the inclined portion closer to the first lumen 4 than the proximal end of the inclined portion, it becomes easier to aspirate bile that is proximal to the liquid suction port 8. The outer edge of the liquid suction port 8 may be formed in a linear or non-linear shape.

[0056] The outer edge of the liquid suction port 8 has a linearly inclined portion, and a notch or protrusion may be formed on the inclined portion. Specifically, when the side of the shaft 2 on which the second tube 6 is disposed is defined as the upper side and the side on which the first tube 3 is disposed is defined as the lower side, the outer edge of the liquid suction port 8 is linearly inclined distally from the upper side to the lower side at the inclined portion, and a notch or protrusion may be formed on the inclined portion. The inclined portion may be formed with either a notch or a protrusion, or both. If the outer edge of the liquid suction port 8 is formed in this manner, it is less likely that gallstones will become trapped in the liquid suction port 8 or that the liquid suction port 8 will be blocked by gallstones when bile is suctioned through the liquid suction port 8.

[0057] FIG. 6 shows an example in which a notch is provided on the outer edge of the liquid suction port 8. In FIG. 6, the outer edge of the liquid suction port 8 has a linearly formed inclined portion 17, and a notch 18 is formed in the inclined portion 17. In the inclined portion 17, the outer edge of the liquid suction port 8 is formed so as to overlap with an imaginary line connecting the upper and lower ends of the liquid suction port 8, and in the notch 18, the outer edge of the liquid suction port 8 is located proximal to the imaginary line. Note that if a protrusion is formed on the inclined portion 17, the outer edge of the liquid suction port 8 is located distal to the imaginary line connecting the upper and lower ends of the liquid suction port 8 at the protruding portion.

[0058] Distal to the liquid suction port 8, the shaft 2 preferably has a tapered section 16 in which the outer diameter decreases toward the distal end. By forming the tip of the shaft 2 in this manner, the shaft 2 can be easily inserted into a bile duct, particularly an intrahepatic bile duct. The tapered section 16 may be formed by processing the shaft 2 so that it tapers, or a separate member having a tapered shape may be attached to the tip of the shaft 2.

[0059] The outer edge of the liquid ejection port 5 is preferably formed so as to extend perpendicularly to the longitudinal direction. Also, the outer edge of the liquid ejection port 5 is preferably chamfered or rounded in side view. If the outer edge of the liquid ejection port 5 is formed in this manner, the bile duct is less likely to be damaged when the shaft 2 is inserted into the bile duct.

[0060] The liquid ejected from the liquid ejection port 5, i.e., the cleaning liquid, is preferably saline. This allows the bile in the bile duct to be diluted with saline while being sucked from the liquid suction port 8, thereby effectively cleaning the inside of the bile duct. For example, if infected bile is present in the bile duct, cleaning the inside of the bile duct can prevent the formation of stones and bile stasis.

[0061] The discharge of cleaning liquid from the liquid discharge port 5 and the suction of bile from the liquid suction port 8 may be performed at the same time, at different times, or alternately. Cleansing the inside of the bile duct in this manner allows the bile in the bile duct to be efficiently suctioned and prevents excessive internal pressure within the bile duct. This prevents the occurrence of sepsis, which would otherwise occur if infected bile flows through the liver into the blood vessels throughout the body.

[0062] Using saline as a rinsing fluid also has the advantage of allowing efficient aspirating of bile due to its difference in specific gravity with bile. During endoscopic retrograde cholangiopancreatography (ERCP), patients are typically placed prone or in the left lateral position, which positions the entrance to the bile duct above the bile duct. When saline is dispensed from the liquid outlet 5 using the catheter 1 in this state, saline, which has a lighter specific gravity than bile, rises to the top of the supernatant liquid as it flows deep into the bile duct, effectively mixing and diluting the bile with the saline. Therefore, the diluted bile can be efficiently removed from the bile duct by aspirating it through the liquid suction port 8.

[0063] A contrast medium may be ejected from the liquid ejection port 5. For example, after the inside of the bile duct is washed with physiological saline, a contrast medium is subsequently injected into the bile duct from the liquid ejection port 5, which makes it easier to perform imaging diagnosis inside the bile duct.

[0064] The shaft 2 may contain a radiopaque material to make it easier to confirm its position under X-ray fluoroscopy, etc. Examples of radiopaque materials include lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, and tantalum. For example, it is preferable to provide a radiopaque marker at the proximal end or distal end of the shaft 2, which makes it possible to confirm the position of the shaft 2 within the body cavity under X-ray fluoroscopy.

[0065] The outer surface of the shaft 2 may be coated with a hydrophilic polymer. This allows the shaft 2 to be easily inserted into the forceps channel through the forceps port of the endoscope. Examples of hydrophilic polymers include polyethylene glycol, poly (2-hydroxyethyl methacrylate), polyacrylamide, polyvinylpyrrolidone, and maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers. [Explanation of symbols]

[0066] 1: Bile aspiration catheter 2: Shaft 3: First tube 4: 1st lumen 5:Liquid outlet 6: Second tube 7: Second lumen 8:Liquid suction port 9: Protective tube 10: Hub 11: Supply connection port 12: Suction connection port 13: Guidewire port 14: First Section 15: Second Section 16: Tapered section 17: Inclined part 18: Notch

Claims

1. A catheter for inserting into a bile duct to aspirate bile, a shaft extending longitudinally from a proximal side to a distal side; a first lumen provided in the shaft, extending longitudinally, and having a liquid outlet at a distal end; a second lumen provided in the shaft, extending in the longitudinal direction, and having a liquid suction port at a distal end; the liquid discharge port is located 3 mm to 10 mm distal to the liquid suction port, A bile aspiration catheter, wherein the shaft has an outer diameter of 4.0 mm or less within a range of at least 250 mm proximally from the distal end.

2. the shaft has a first section having a predetermined length proximal to the liquid suction port and a second section proximal to the first section, The bile aspiration catheter according to claim 1 , wherein the outer diameter of the shaft in the second section is larger than the outer diameter of the shaft in the first section.

3. an inner diameter of the first lumen in the second section is larger than an inner diameter of the first lumen in the first section; The bile aspiration catheter according to claim 2 , wherein the inner diameter of the second lumen in the second section is larger than the inner diameter of the second lumen in the first section.

4. 4. The bile aspiration catheter according to claim 2, wherein the length of the first section is 50 mm or more and 200 mm or less.

5. 5. The bile aspiration catheter according to claim 2, wherein the outer diameter of the shaft in the first section is 2.5 mm or less.

6. 6. The bile aspiration catheter according to claim 1, wherein the cross-sectional area of ​​the second lumen is larger than the cross-sectional area of ​​the first lumen in a cross section perpendicular to the longitudinal direction of the shaft.

7. 7. The bile aspiration catheter according to claim 1, wherein the outer edge of the liquid aspiration port has a sloped portion, and the distal end of the sloped portion is located closer to the first lumen than the proximal end of the sloped portion.

8. 8. The bile aspiration catheter according to claim 1, wherein the shaft has a tapered portion distal to the liquid aspiration port, the outer diameter of which decreases toward the distal end.

9. 9. The bile aspiration catheter according to claim 1, wherein the liquid discharged from the liquid discharge port is physiological saline.

10. The bile aspiration catheter according to any one of claims 1 to 9, wherein the first lumen also serves as a guidewire lumen.

11. The bile aspiration catheter according to any one of claims 1 to 10, which is inserted into the intrahepatic bile duct.

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