Bile aspiration catheter

Abstract

To provide a bile aspiration catheter capable of optimally aspirating bile on a proximal side of an aspiration port besides bile on the distal side of the aspiration port.SOLUTION: A catheter 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 aspiration port 8 is located on the proximal side with respect to the liquid discharge port 5, and the shaft 2 includes, on an outer surface, a plurality of protrusions 14 in the vicinity of the proximal side of the liquid aspiration port 8.SELECTED DRAWING: Figure 2

Description

Technical Field

[0004] ,

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

Background Art

[0002] When the bile duct is blocked by gallstones, tumors, etc., or the flow of bile in the bile duct is inhibited, bile may stagnate in the bile duct and cause bacterial infection. Bacterial infection of bile causes cholangitis, and if the bile containing bacteria flows into the systemic blood through the liver, it may cause sepsis. In such cases, a procedure for discharging bile from the bile duct is required, and percutaneous transhepatic cholangial drainage (PTCD), endoscopic retrograde biliary drainage (ERBD), etc. are performed.

[0003] As a catheter inserted into the bile duct and used, for example, in Patent Document 1, there is a bile duct drainage catheter including a catheter tube whose distal end side is inserted into the bile duct. The catheter tube has a main body portion whose outer diameter is substantially the same along the longitudinal direction, a first tapered portion connected to the distal end side of the main body portion and having a smaller outer diameter toward the distal end side, a small-diameter straight body portion connected to the distal end side of the first tapered portion and having an outer diameter substantially the same along the longitudinal direction, and a second tapered portion connected to the distal end side of the small-diameter straight body portion and having a smaller outer diameter toward the distal end side. A bile duct drainage catheter is disclosed in which the outer diameter of the small-diameter straight body portion is 20 to 80% of the outer diameter of the main body portion, and the length of the small-diameter straight body portion is 30 to 250 mm. Patent Document 2 discloses an elongated medical member including a long insertion portion provided with a plurality of lumens through which a working treatment tool for performing a predetermined medical act can be inserted, and a guide portion extending from the tip of the insertion portion to guide the insertion portion. An opening is formed in the tip surface of the guide portion, and fluid supply lumens are formed in the insertion portion and the guide portion. Patent Document 2 describes that bile in the bile duct may be aspirated from the opening at the tip of the insertion portion.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-329314 [Patent Document 2] Japanese Patent Publication No. 2011-251140 [Overview of the project] [Problems that the invention aims to solve]

[0005] When aspirating bile from the bile duct through the suction port at the distal end of a catheter, it is desirable to be able to aspirate not only the bile distal to the suction port but also the bile proximal to the suction port. This facilitates the bile aspiration procedure using the catheter. Furthermore, it is desirable to avoid aspirating gallstones from the bile duct as much as possible. The present invention has been made in view of the above circumstances, and its purpose is to provide a bile aspiration catheter that can suitably aspirate not only the bile distal to the suction port but also the bile proximal to the suction port. [Means for solving the problem]

[0006] The bile aspiration catheter of the present invention, which has been able to solve the aforementioned problems, is a catheter for aspirating bile by insertion into the bile duct, and is characterized by having a shaft that extends longitudinally from the proximal to the distal side, a first lumen provided on the shaft that extends longitudinally and has a liquid discharge port at its distal end, and a second lumen provided on the shaft that extends longitudinally and has a liquid aspiration port at its distal end, wherein the liquid aspiration port is located proximal to the liquid discharge port, and a plurality of protrusions are provided on the outer surface of the shaft near the proximal side of the liquid aspiration port.

[0007] The bile aspiration catheter of the present invention can dilute the bile accumulated in the bile duct and reduce its viscosity by discharging a lavage solution into the bile duct from the liquid discharge port. This makes it easier to aspirate the bile, which has been diluted and reduced in viscosity by the lavage solution, from the liquid aspiration port. At that time, since multiple protrusions are provided on the outer surface of the shaft near the proximal side of the liquid aspiration port, not only bile distal to the liquid aspiration port but also bile proximal to the liquid aspiration port can be suitably aspirated. In other words, the multiple protrusions provided on the outer surface of the shaft near the proximal side of the liquid aspiration port make it difficult for gallstones to accumulate near the proximal side of the liquid aspiration port, and make it difficult for gallstones to enter the liquid aspiration port. Furthermore, even if gallstones accumulate near the proximal side of the liquid aspiration port, bile proximal to the liquid aspiration port can be easily aspirated from the liquid aspiration port through the gaps between the protrusions.

[0008] The projection is preferably located proximal to the distal end of the liquid aspiration port with respect to the longitudinal direction of the shaft, and distal to a point 50 mm proximal to the proximal end of the liquid aspiration port. The height of the projection is preferably 0.05 to 0.25 times the outer diameter of the shaft near the proximal side of the liquid aspiration port. In a cross-section perpendicular to the longitudinal direction of the shaft, the projection is preferably located closer to the second lumen than the first lumen. Furthermore, in the longitudinal section of the shaft where the projection is provided, the area ratio of the projection to the outer surface of the shaft is preferably 2% to 50%. By forming the projection in this way, gallstones are less likely to accumulate near the proximal side of the liquid aspiration port on the outer surface of the shaft, and bile located proximal to the liquid aspiration port is more easily aspirated through the gaps between the projections and into the liquid aspiration port.

[0009] Preferably, 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. When the liquid aspiration port is formed in this way, the size of the liquid aspiration port can be made wider, making it easier to aspirate bile. In addition, by having the distal end of the sloped portion located closer to the first lumen than the proximal end of the sloped portion, it becomes easier to aspirate bile that is proximal to the liquid aspiration port.

[0010] In a cross-section perpendicular to the longitudinal direction of the shaft, it is preferable that the cross-sectional area of ​​the second lumen is larger than that of the first lumen. This makes it less likely for gallstones or other debris to clog the second lumen when aspirating bile. In addition, it becomes easier to forcefully discharge the irrigation solution from the liquid outlet of the first lumen, making it easier to irrigate deeper into the bile duct. [Effects of the Invention]

[0011] The bile aspiration catheter of the present invention has multiple protrusions on the outer surface of the shaft near the proximal side of the liquid aspiration port, which makes it difficult for gallstones to accumulate near the proximal side of the liquid aspiration port and prevents gallstones from entering the liquid aspiration port. Furthermore, even if gallstones accumulate near the proximal side of the liquid aspiration port, bile located proximal to the liquid aspiration port can be easily aspirated through the gaps between the protrusions. Therefore, not only bile distal to the liquid aspiration port but also bile located proximal to the liquid aspiration port can be suitably aspirated. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows an example of a bile aspiration catheter according to an embodiment of the present invention, and represents an overall side view of the bile aspiration catheter. [Figure 2] Figure 1 shows a side view of the distal end of the bile aspiration catheter. [Figure 3] Figure 1 shows a perspective view of the distal end of the bile aspiration catheter. [Figure 4] Figure 2 shows a front view of the bile aspiration catheter as seen from the distal end. [Figure 5] Figure 2 shows a modified side view of the distal end of the bile aspiration catheter. [Figure 6] Figure 2 shows a modified side view of the distal end of the bile aspiration catheter. [Figure 7] Figure 1 shows a cross-sectional view of the bile aspiration catheter from point VII to VII. [Figure 8] Figure 2 shows a modified side view of the distal end of the bile aspiration catheter. [Modes for carrying out the invention]

[0013] The bile aspiration catheter of the present invention will be described in detail below based on the embodiments described below. However, the present invention is not limited by the embodiments described below, and it is certainly possible to implement the invention with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component reference numerals may be omitted in the drawings for convenience, in which case refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping to understand the features of the present invention.

[0014] A bile aspiration catheter according to an embodiment of the present invention will be described with reference to Figures 1 to 8. Figure 1 is an example of a bile aspiration catheter according to an embodiment of the present invention, showing an overall side view of the bile aspiration catheter. Figures 2 and 3 show a side view and a perspective view of the distal end of the bile aspiration catheter shown in Figure 1, respectively. Figure 4 shows a front view of the bile aspiration catheter shown in Figure 2, viewed from the distal side. Figure 7 shows a VII-VII cross-sectional view of the bile aspiration catheter shown in Figure 1. Figures 5, 6, and 8 show modified examples of the side view of the distal end of the bile aspiration catheter shown in Figure 2.

[0015] The bile aspiration catheter 1 is a catheter used to aspirate bile by inserting it into the bile duct. The bile aspiration catheter 1 of the present invention can aspirate bile accumulated in the bile duct while supplying liquid into the bile duct to flush it. Hereinafter, the bile aspiration catheter will be simply referred to as "catheter".

[0016] The catheter 1 has a shaft 2 extending in the longitudinal direction. In the catheter 1, the longitudinal direction is determined based on the extending direction of the shaft 2. The catheter 1 has a proximal side and a distal side as one side and the other side with respect to the longitudinal direction. The proximal side refers to the direction on the side of the user of the catheter 1, that is, the operator's hand, and the distal side refers to the opposite direction of the proximal side, that is, the direction on the side of the treatment target. The shaft 2 has a radial direction as the orthogonal direction with respect to the longitudinal direction. In FIG. 1, the right side of the figure corresponds to the proximal side, and the left side of the figure corresponds to the distal side.

[0017] The shaft 2 has a first lumen 4 having a liquid discharge port 5 at the distal end and a second lumen 7 having a liquid suction port 8 at the distal end. The first lumen 4 and the second lumen 7 each extend in the longitudinal direction and are arranged side by side in the radial direction. The shaft 2 has a first tube 3 and a second tube 6, and the inner cavity of the first tube 3 can be used as the first lumen 4, and the inner cavity of the second tube 6 can be used as the second lumen 7. The first tube 3 and the second tube 6 are arranged side by side, a liquid discharge port 5 is formed at the distal end of the first tube 3, and a liquid suction port 8 is formed at the distal end of the second tube 6. The first tube 3 and the second tube 6 are preferably welded or adhered to each other and integrated, or the first tube 3 and the second tube 6 are arranged in the inner cavity of the protection tube 9, and the first tube 3 and the second tube 6 are integrated by the protection tube 9. Although not shown in the drawings, it is also possible to form two inner cavities in one tube to serve as the first lumen and the second lumen.

[0018] When using the catheter 1, a liquid (washing liquid) to be supplied into the bile duct flows through the first lumen 4, and the liquid is discharged into the bile duct from the liquid discharge port 5 at the distal end of the first lumen 4. Therefore, the first lumen 4 preferably has a proximal opening, and a liquid supply part is preferably provided in communication with the proximal opening of the first lumen 4. Examples of the liquid supply part include a syringe and a pump.

[0019] Bile and the like accumulated in the bile duct are sucked from the liquid suction port 8 at the distal end of the second lumen 7 and discharged from the bile duct through the second lumen 7. Therefore, the second lumen 7 preferably has a proximal opening, and a liquid suction part is preferably provided in communication with the proximal opening of the second lumen 7. Examples of the liquid suction part include a syringe, a pump, and the like. As the syringe of the liquid suction part, a backlock syringe may be used.

[0020] The first lumen 4 can also serve as a guide wire lumen. By making the first lumen 4 also serve as a guide wire lumen, the outer diameter of the shaft 2 can be reduced. In addition, bile can be sucked and the inside of the bile duct can be washed without removing the guide wire, leading to simplification of the procedure and shortening of the operation time.

[0021] Preferably, a hub 10 is 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. Preferably, the liquid supply part is connected to the supply connection port 11 of the hub 10, and the liquid suction part is 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.

[0022] Preferably, the hub 10 further has a guide wire port 13. The guide wire port 13 is preferably provided in communication with the first lumen 4. In this case, inside the hub 10, an internal passage communicating with the first lumen 4 branches into two, and one of the branched passages is connected to the supply connection port 11 and the other is connected to the guide wire port 13.

[0023] The hub 10 may further have auxiliary ports into which other medical devices can be inserted. The auxiliary ports can be provided, for example, in communication with the second lumen 7. In this case, the internal passage in the hub 10 that communicates 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. Examples of other medical devices include cytological brushes, which allow for the collection of a specimen for cytology immediately after bile aspiration.

[0024] 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 of the hub 10 and the supply connection port 11, liquid can be flowed in one direction from the supply connection port 11 towards the first lumen 4. By providing a check valve in the internal passage connecting the second lumen 7 of the hub 10 and the suction connection port 12, liquid can be flowed in one direction from the second lumen 7 towards the suction connection port 12.

[0025] 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 internal passages that branch into two or more, and each internal passage may have two or more ports communicating with it. For example, the first hub connected to the first lumen 4 may have a supply connection port 11 and a guide wire port 13. The second hub connected to the second lumen 7 may have a suction connection port 12 and the auxiliary ports described above. Check valves may be provided in the internal passages of the first hub and / or the second hub.

[0026] The longitudinal length of shaft 2 is preferably 1500 mm or more, more preferably 1800 mm or more, preferably 3000 mm or less, and more preferably 2800 mm or less. The outer diameter of shaft 2 is preferably 1.2 mm or more, more preferably 1.3 mm or more, even more preferably 1.4 mm or more, preferably 8.0 mm or less, more preferably 7.0 mm or less, and even more preferably 6.0 mm or less. The outer diameter of shaft 2 may be even smaller, for example 4.0 mm or less, 3.6 mm or less, or 3.2 mm or less. The inner diameters of the first lumen 4 and the second lumen 7 are preferably 1.0 mm or more, more preferably 1.1 mm or more, even more preferably 1.3 mm or more, preferably 3.5 mm or less, more preferably 3.0 mm or less, and even more preferably 2.5 mm or less. The inner diameters of the first lumen 4 and the second lumen 7 may be even smaller, for example 2.2 mm or less, 2.0 mm or less, or 1.9 mm or less.

[0027] In a cross-section perpendicular to the longitudinal direction of shaft 2, the shape of the outer edge of shaft 2, the shape of the outer edge of the first tube 3, the shape of the outer edge of the second tube 6, the shape of the first lumen 4, and the shape of the second lumen 7 are not particularly limited and can be circular, elliptical, oblong, egg-shaped, polygonal, irregular, etc. If the shape of the outer edge of shaft 2 or the shapes of the first lumen 4 and the second lumen 7 are not circular, the outer diameter of shaft 2 and the inner diameters of the first lumen 4 and the second lumen 7 described above represent the average value of the major axis and the minor axis. Regarding the major axis and minor axis, taking the outer edge of shaft 2 as an example, the major axis of the outer edge of shaft 2 means the length in the major axis direction of the outer edge of shaft 2 (the maximum diameter of the outer edge), and the minor axis of the outer edge of shaft 2 means the longest length in the minor axis direction that is perpendicular to the major axis direction of shaft 2. Furthermore, the shape of the outer edge of shaft 2, the shape of the outer edge of the first tube 3, the shape of the outer edge of the second tube 6, the shape of the first lumen 4, and the shape of the second lumen 7 are preferably circular, oval, elliptical, or egg-shaped. The shaft 2 may be formed with substantially the same outer diameter along its entire longitudinal direction, or it may be formed so that the outer diameter differs between a part of the longitudinal direction and other parts. For example, the outer diameter of the shaft 2 may differ between the distal and proximal parts of the shaft 2. The inner and outer diameters of the first tube 3 and / or the second tube 6 may also differ between the distal and proximal parts of the shaft 2.

[0028] In one embodiment, it is preferable that the outer diameter of the shaft 2 at its proximal end is larger than the outer diameter of the shaft 2 at its distal end. In this case, the shaft 2 may be formed such that the outer diameter of the first tube 3 at its proximal end is larger than the outer diameter of the first tube 3 at its distal end, or the outer diameter of the second tube 6 at its proximal end is larger than the outer diameter of the second tube 6 at its distal end, or both. Furthermore, the shaft 2 may be formed such that the outer diameter of the protective tube 9 at its proximal end is larger than the outer diameter of the protective tube 9 at its distal end, or the protective tube 9 may not be provided at the distal end of the shaft 2, but only at its proximal end. By configuring the shaft 2 in this way, it becomes easier to insert the distal end of the shaft 2 deeper into the bile duct while ensuring the rigidity of the proximal end of the shaft 2.

[0029] The shaft 2 may be configured such that the inner diameter of the first tube 3 at the proximal end of the shaft 2 is larger than the inner diameter of the first tube 3 at the distal end of the shaft 2, or the inner diameter of the second tube 6 at the proximal end of the shaft 2 is larger than the inner diameter of the second tube 6 at the distal end of the shaft 2, or both. With the shaft 2 configured in this way, the lavage fluid can be discharged more effectively, or bile can be aspirated.

[0030] The shaft 2, or the first tube 3, second tube 6, and protective tube 9 that constitute the shaft 2, can be made of resin. Examples of resins include 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, fluororesins such as PTFE, PFA, and ETFE, polyvinyl chloride resins, and silicone resins.

[0031] The shaft 2, the first tube 3, the second tube 6, and the protective tube 9 may be composed 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 of their longitudinal direction composed of a single layer, while other parts are composed of multiple layers.

[0032] 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. Preferably, the reinforcing layer is placed between an inner layer and an outer layer made of resin.

[0033] The reinforcing layer can be made of metal wires, fibers, etc. Examples of materials for the metal wires include stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy. Stainless steel is preferred among these. The metal wire may be a single wire or a stranded wire. 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.

[0034] The shape of the reinforcing layer is not particularly limited, but helical, mesh-like, and braided shapes are preferred. Among these, a braided shape is more preferred because it can effectively increase the rigidity of the shaft 2.

[0035] The shaft 2 is configured such that the liquid suction port 8 is located proximal to the liquid discharge port 5. This allows the liquid discharge port 5 to be located at the tip of the shaft 2, making it easier to insert it deeper into the bile duct for irrigation and aspiration. Since the liquid discharge port 5 is formed at the distal end of the first lumen 4, the irrigation fluid that has been transported through the first lumen 4 to its distal end is discharged distally from the liquid discharge port 5, making it possible to irrigate the inside of the bile duct distal to the liquid discharge port 5. In addition, bile is relatively viscous, and bacterial-infected bile is even more viscous. By discharging the irrigation fluid into the bile duct from the liquid discharge port 5, the bile accumulated in the bile duct is diluted, and its viscosity can be reduced. On the other hand, the positioning of the liquid suction port 8 proximal to the liquid discharge port 5 makes it easier to aspirate bile accumulated in the bile duct. That is, by positioning the liquid suction port 8 proximal to the liquid discharge port 5, it becomes easier to aspirate bile that has been diluted by the irrigation fluid and has reduced viscosity from the liquid suction port 8. Therefore, it becomes easier to aspirate bile from the liquid aspirator port 8, and the aspirated bile is less likely to clog the second lumen 7.

[0036] The liquid suction port 8 is preferably located at least 3 mm proximal to the liquid discharge port 5, more preferably at least 4 mm, even more preferably at least 5 mm, preferably 30 mm or less, more preferably 20 mm or less, and even more preferably 15 mm or less. By positioning the liquid suction port 8 and liquid discharge port 5 in this manner, the aspiration of undiluted bile is suppressed, and it becomes easier to aspirate bile diluted with the lavage solution. In addition, it becomes easier to aspirate bile accumulated deep inside the bile duct, and the amount of bile left behind can be reduced. The separation distance between the liquid suction port 8 and the liquid discharge port 5 is determined by measuring the longitudinal separation distance between the distal end of the liquid suction port 8 and the proximal end of the liquid discharge port 5.

[0037] When inserting shaft 2 into the bile duct to aspirate bile, it is desirable to be able to aspirate not only the bile distal to the liquid aspiration port 8, but also the bile proximal to the liquid aspiration port 8. This makes the bile aspiration procedure using catheter 1 easier. At this time, it is also desirable to avoid aspirating gallstones in the bile duct as much as possible, thereby preventing gallstones from blocking the second lumen 7. Gallstones distal to the tip of shaft 2 can be kept away from the liquid aspiration port 8 by discharging irrigation fluid from the liquid discharge port 5. On the other hand, gallstones proximal to the liquid aspiration port 8 may move toward the liquid aspiration port 8 as the bile proximal to the liquid aspiration port 8 moves toward it. As a result, gallstones tend to accumulate on the outer surface of shaft 2 near the proximal side of the liquid aspiration port 8, and if gallstones accumulate in this area, it becomes difficult to aspirate bile proximal to the liquid aspiration port 8. Furthermore, there is a risk that gallstones may be drawn to the liquid suction port 8 from the proximal side and become lodged in the second lumen 7.

[0038] Therefore, multiple protrusions 14 are provided on the outer surface of the shaft 2 near the proximal side of the liquid suction port 8. By providing these protrusions 14 on the outer surface of the shaft 2 near the proximal side of the liquid suction port 8, gallstones are less likely to accumulate near the proximal side of the liquid suction port 8, and gallstones are less likely to enter the liquid suction port 8. In addition, even if gallstones gather near the proximal side of the liquid suction port 8, bile located proximal to the liquid suction port 8 can be more easily aspirated from the liquid suction port 8 through the gaps between the protrusions 14.

[0039] The projection 14 should be provided so as to protrude radially outward from the outer surface of the shaft 2. The projection 14 has a base that serves as the starting point for protruding from the outer surface of the shaft 2, and a top that serves as the protruding tip. The length from the base to the top is the height of the projection 14.

[0040] The projection 14 may be provided on the outer surface of the first tube 3, on the outer surface of the second tube 6, or on the outer surface of the protective tube 9. Figures 2 to 4 show an example where the projection 14 is provided on the outer surface of the second tube 6, Figure 5 shows an example where the projection 14 is provided on the outer surfaces of both the first tube 3 and the second tube 6, and Figure 6 shows an example where the projection 14 is provided on the outer surface of the protective tube 9. In Figure 4, there is a gap between the protective tube 9 and the first tube 3 and the second tube 6, but there does not have to be a gap between the protective tube 9 and the first tube 3 and the second tube 6. For example, after arranging each tube as in Figure 4, a heat-shrinkable tube can be placed over the outside and heat-processed to form a gap-free structure between the protective tube 9 and the first tube 3 and the second tube 6.

[0041] The projection 14 is preferably provided near the proximal side of the liquid suction port 8, in a range that is proximal to the distal end of the liquid suction port 8 and distal to a point 50 mm proximal to the proximal end of the liquid suction port 8, with respect to the longitudinal direction of the shaft 2. The projection 14 only needs to be provided in at least a part of this range. Furthermore, it is preferable that the projection 14 is not provided distal to or proximal to this range. It is more preferable that the projection 14 is provided in a range that is proximal to the distal end of the liquid suction port 8 and distal to a point 30 mm proximal to the proximal end of the liquid suction port 8, and even more preferable that it is provided in a range that is proximal to the distal end of the liquid suction port 8 and distal to a point 20 mm proximal to the proximal end of the liquid suction port 8.

[0042] The shape of the projection 14 is not particularly limited. The planar shape of the projection 14, that is, the shape of the projection 14 when viewed from above on the outer surface of the shaft 2, can be, for example, circular, elliptical, oblong, polygonal (quadrilateral, hexagonal, octagonal, etc.), linear, meandering, zigzag, etc. The drawing shows an example in which the projection 14 has a circular planar shape.

[0043] When viewing the projection 14 from above on the outer surface of the shaft 2, the length of the projection 14 in the direction perpendicular to the longitudinal direction of the shaft 2 is preferably 0.05 times or more, more preferably 0.08 times or more, and preferably 0.25 times or less, and more preferably 0.20 times or less, the outer diameter of the shaft 2 near the proximal side of the liquid aspiration port 8. By forming the projection 14 with such a size, gallstones are less likely to accumulate on the outer surface of the shaft 2 near the proximal side of the liquid aspiration port 8, and bile located proximal to the liquid aspiration port 8 is more easily aspirated from the liquid aspiration port 8 through the gaps between the projections 14.

[0044] The height of the projection 14 is preferably 0.05 times or more, and more preferably 0.08 times or more, the outer diameter of the shaft 2 near the proximal side of the liquid aspiration port 8. By forming the projection 14 at such a height, gallstones are less likely to accumulate on the outer surface of the shaft 2 near the proximal side of the liquid aspiration port 8, and bile located proximal to the liquid aspiration port 8 can be more easily aspirated from the liquid aspiration port 8 through the gaps between the projections 14. The height of the projection 14 is preferably 0.25 times or less, more preferably 0.20 times or less, and even more preferably 0.15 times or less, the outer diameter of the shaft 2 near the proximal side of the liquid aspiration port 8. This prevents the projection 14 from being formed excessively large, making it easier to insert the shaft 2 deep into the bile duct, for example, into the intrahepatic bile duct.

[0045] In the above, the outer diameter of shaft 2 refers to the outer diameter of shaft 2 excluding the projection 14. If the shape of the outer edge of shaft 2 is not circular, it refers to the average value of the major and minor axes. Furthermore, the length and height of the projection 14 relative to the outer diameter of shaft 2 are determined by measuring the length or height of the projection 14 and measuring the outer diameter of shaft 2 at the same position relative to the measurement point in the longitudinal direction of shaft 2.

[0046] It is preferable that the projection 14 is formed so as not to widen from the base to the top. That is, it is preferable that the projection 14 is formed to be the same width from the base to the top, or to be formed so as to narrow in width. The projection 14 may be formed so that a part of it is the same width from the base to the top, and the other part is formed so as to narrow in width. If the projection 14 is formed in this way, it becomes less likely that gallstones will get stuck and block between the projections 14.

[0047] In the longitudinal section of the shaft 2 where the projections 14 are provided, the area ratio of the projections 14 to the outer surface of the shaft 2 is preferably 2% or more, more preferably 4% or more, preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less. When the projections 14 are formed in this manner, gallstones are less likely to accumulate near the proximal side of the liquid aspiration port 8 on the outer surface of the shaft 2, and bile located proximal to the liquid aspiration port 8 is more easily aspirated from the liquid aspiration port 8 through the gaps between the projections 14. The longitudinal section of the shaft 2 where the projections 14 are provided means the section of the shaft 2 from the distal end of the most distal projection 14 to the proximal end of the most proximal projection 14 among the multiple projections 14 provided.

[0048] It is preferable that multiple protrusions 14 are arranged on the outer surface of the shaft 2 at different positions in the circumferential direction of the shaft 2. For example, as shown in Figure 4, when viewing the shaft 2 from the distal side, it is preferable that the protrusions 14 are arranged at three or more different locations in the circumferential direction of the shaft 2, more preferably four or more locations, and even more preferably five or more locations. It is also preferable that multiple protrusions 14 are arranged on the outer surface of the shaft 2 at different positions in the longitudinal direction of the shaft 2. The protrusions 14 may be arranged at two or more different locations in the longitudinal direction of the shaft 2, or at three or more locations.

[0049] It is preferable that more of the projections 14 are arranged on the second lumen 7 side than on the first lumen 4 side. That is, in a cross-section perpendicular to the longitudinal direction of the shaft 2, it is preferable that the number of projections 14 located closer to the second lumen 7 than to the first lumen 4 is greater than the number of projections located closer to the first lumen 4 than to the second lumen 7. For example, in Figures 2 to 4 and Figure 6, the projections 14 are arranged on the shaft 2 in this manner. By providing the projections 14 in this way, gallstones located proximal to the liquid aspiration port 8 are less likely to enter the liquid aspiration port 8. In addition, the outer diameter of the shaft 2 including the projections 14 can be reduced, making it easier to insert the shaft 2 into the bile duct. For example, if the projections 14 are provided on the outer surface of the second tube 6, the projections 14 are located closer to the second lumen 7 than to the first lumen 4, and if the projections 14 are provided on the outer surface of the first tube 3, the projections 14 are located closer to the first lumen 4 than to the second lumen 7. If a projection 14 is provided on the outer surface of the protective tube 9, then if the second tube 6 is located inside the area where the projection 14 is provided on the protective tube 9, the projection 14 will be located closer to the second lumen 7 than to the first lumen 4. If the first tube 3 is located inside the area where the projection 14 is provided on the protective tube 9, then the projection 14 will be located closer to the first lumen 4 than to the second lumen 7.

[0050] In a cross-section perpendicular to the longitudinal direction of the shaft 2, it is preferable that the projections 14 are located closer to the second lumen 7 than to the first lumen 4. That is, it is preferable that all projections 14 on the outer surface of the shaft 2 be located closer to the second lumen 7 than to the first lumen 4. This makes it more difficult for gallstones located proximal to the liquid aspiration port 8 to enter the liquid aspiration port 8. In addition, by not providing projections 14 on the first lumen 4 side, it becomes easier to insert the shaft 2 deeper into the bile duct, for example, into the intrahepatic bile duct.

[0051] As shown in Figures 2 to 4, it is preferable that the projection 14 is provided on the outer surface of the second tube 6. In this case, the distal end of the second tube 6 is not covered by the protective tube 9, and the projection 14 is provided on the outer surface of the distal end of the second tube 6. By providing the projection 14 in this way, the projection 14 can be stably provided at the proximal end of the liquid suction port 8, and the projection 14 can be provided closer to the liquid suction port 8.

[0052] Preferably, the projections 14 are arranged at approximately equal intervals in the circumferential direction of the shaft 2 on the outer surface of the second tube 6 in the portion that does not come into contact with the first tube 3. In this case, the projections 14 will be arranged at three or more different locations on the outer surface of the second tube 6 in the circumferential direction of the shaft 2. By providing the projections 14 in this way, gallstones located proximal to the liquid aspiration port 8 are less likely to enter the liquid aspiration port 8, and bile located proximal to the liquid aspiration port 8 is more easily aspirated from the liquid aspiration port 8 through the gaps between the projections 14.

[0053] When the projection 14 is provided on the outer surface of the second tube 6, the length of the projection 14 in the direction perpendicular to the longitudinal direction of the second tube 6 when viewed from above on the outer surface of the second tube 6 is preferably 0.1 times or more, more preferably 0.15 times or more, preferably 0.5 times or less, and more preferably 0.4 times or less, of the outer diameter of the second tube 6 near the proximal side of the liquid suction port 8. The height of the projection 14 is preferably 0.1 times or more, more preferably 0.15 times or more, preferably 0.5 times or less, and more preferably 0.4 times or less, of the outer diameter of the second tube 6 near the proximal side of the liquid suction port 8.

[0054] In a cross-section perpendicular to the longitudinal direction of shaft 2, the cross-sectional area of ​​the second lumen 7 is preferably larger than the cross-sectional area of ​​the first lumen 4 (see Figure 7). This makes it less likely for gallstones or the like to clog the second lumen 7 when aspirating bile. It also makes it easier to forcefully discharge the cleaning solution from the liquid outlet 5 of the first lumen 4, making it easier to clean deeper into the bile duct. The cross-sectional area of ​​the second lumen 7 is preferably 1.1 times or more, more preferably 1.2 times or more, 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. In Figure 7, there is a gap between the protective tube 9 and the first tube 3 and the second tube 6, but there does not need to be a gap between the protective tube 9 and the first tube 3 and the second tube 6. For example, after placing the first tube 3 and the second tube 6 inside the lumen of the protective tube 9, a heat-shrinkable tube can be placed over the outside and heat-processed to create a gap between the protective tube 9 and the first tube 3 and the second tube 6.

[0055] The liquid aspiration port 8 is preferably formed in an inclined shape. Specifically, the outer edge of the liquid aspiration port 8 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. When the liquid aspiration port 8 is formed in this way, the size of the liquid aspiration port 8 can be made wider, making it easier to aspirate bile. In addition, by having the distal end of the inclined portion located 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 aspiration port 8. The outer edge of the liquid aspiration port 8 may be formed in a straight line or a non-straight line.

[0056] The outer edge of the liquid suction port 8 has a linearly formed inclined portion, and notches or protrusions may be formed in this inclined portion. Specifically, when the side of the shaft 2 on which the second tube 6 is located is considered the upper side and the side on which the first tube 3 is located is considered the lower side, the outer edge of the liquid suction port 8 is linearly inclined distally from the upper side to the lower side in the inclined portion, and notches or protrusions may be formed in this inclined portion. Either a notch or a protrusion may be formed in the inclined portion, or both may be formed. If the outer edge of the liquid suction port 8 is formed in this way, it becomes less likely that gallstones will become lodged in the liquid suction port 8 or that the liquid suction port 8 will be blocked by gallstones when bile is aspirated from the liquid suction port 8.

[0057] Figure 8 shows an example in which a notch is provided on the outer edge of the liquid suction port 8. In Figure 8, the outer edge of the liquid suction port 8 has a linearly formed inclined portion 15, and a notch 16 is formed in the inclined portion 15. In the inclined portion 15, the outer edge of the liquid suction port 8 is formed to coincide with a hypothetical straight line connecting the upper and lower ends of the liquid suction port 8, and in the notch 16, the outer edge of the liquid suction port 8 is located proximal to the hypothetical straight line. If a protrusion is formed in the inclined portion 15, in the protrusion, the outer edge of the liquid suction port 8 is located distal to the hypothetical straight line connecting the upper and lower ends of the liquid suction port 8.

[0058] It is preferable that the shaft 2 has a tapered portion 17 distal to the liquid suction port 8, where the outer diameter decreases towards the distal end. By shaping the tip of the shaft 2 in this way, it becomes easier to insert the shaft 2 into the bile duct, especially into the intrahepatic bile duct. The tapered portion 17 may be formed by machining the shaft 2 to become narrower, or a separate member with a tapered shape may be attached to the tip of the shaft 2.

[0059] The outer edge of the liquid outlet 5 is preferably formed to extend perpendicular to the longitudinal direction. Furthermore, the outer edge of the liquid outlet 5 is preferably chamfered or rounded in a side view. If the outer edge of the liquid outlet 5 is formed in this way, it becomes less likely to damage the bile duct when inserting the shaft 2 into the bile duct.

[0060] The liquid discharged from the liquid discharge port 5, i.e., the irrigation solution, is preferably physiological saline. This allows the bile in the bile duct to be diluted with physiological saline while being aspirated from the liquid suction port 8, thereby effectively irrigating the bile duct. For example, if there is infected bile in the bile duct, irrigating the bile duct can suppress the formation of gallstones and bile stasis.

[0061] The discharge of the lavage solution from the liquid discharge port 5 and the aspiration of bile from the liquid aspirator port 8 may be performed at the same time, at different times, or alternately. By lavaging the bile duct in this way, bile can be efficiently aspirated from the bile duct, and the internal pressure of the bile duct can be prevented from becoming excessively high. Therefore, the occurrence of sepsis caused by infected bile flowing through the liver into the blood vessels throughout the body can be suppressed.

[0062] Using saline solution as a lavage solution allows for efficient bile aspiration due to the difference in specific gravity between saline and bile. During endoscopic retrograde cholangiopancreatography (ERCP), the patient is usually placed prone or left lateral decubitus. In this position, the opening of the bile duct is located above the inside of the bile duct. When catheter 1 is used in this position and saline solution is discharged from liquid outlet 5, saline solution has a lower specific gravity than bile. Therefore, when saline solution flows deep into the bile duct, it rises as a supernatant, efficiently mixing and diluting the bile. As a result, the diluted bile can be efficiently removed from the bile duct by aspirating it from liquid aspirator 8.

[0063] Contrast agent may be discharged from the liquid outlet 5. For example, after flushing the bile duct with saline solution, injecting contrast agent into the bile duct from the liquid outlet 5 makes it easier to perform imaging diagnosis of the bile duct.

[0064] The shaft 2 may contain a radiopaque material to facilitate its position under X-ray fluoroscopy. 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 radiopaque markers at the proximal and distal ends of the shaft 2, thereby allowing the position of the shaft 2 within the body cavity to be confirmed under X-ray fluoroscopy.

[0065] The shaft 2 may have its outer surface coated with a hydrophilic polymer. This facilitates insertion of the shaft 2 into the forceps channel from the forceps channel 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 copolymer. [Explanation of symbols]

[0066] 1: Bile aspiration catheter 2: Shaft 3: First tube 4: First 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: Guide wire port 14:Protrusion 15: Inclined part 16: Notch 17: Tapered section

Claims

1. A catheter for inserting into the bile duct to aspirate bile, A shaft that extends longitudinally from the proximal to the distal side, A first lumen is provided on the shaft, extending in the longitudinal direction and having a liquid discharge port at its distal end, The shaft is provided with a second lumen that extends in the longitudinal direction and has a liquid suction port at its distal end, The liquid suction port is located proximal to the liquid discharge port. Multiple protrusions are provided on the outer surface of the shaft near the proximal side of the liquid suction port. The projection is provided in a range proximal to the distal end of the liquid aspiration port with respect to the longitudinal direction of the shaft, and distal to a point 50 mm proximal to the proximal end of the liquid aspiration port, and is not provided distal to or proximal to that range.

2. The bile aspiration catheter according to claim 1, wherein the height of the projection is 0.05 times or more and 0.25 times or less the outer diameter of the shaft near the proximal side of the liquid aspiration port.

3. The bile aspiration catheter according to claim 1 or 2, wherein in a cross section perpendicular to the longitudinal direction of the shaft, the projection is provided closer to the second lumen than to the first lumen.

4. The bile aspiration catheter according to any one of claims 1 to 3, wherein in the longitudinal section of the shaft on which the projection is provided, the area ratio of the projection on the outer surface of the shaft is 2% or more and 50% or less.

5. The bile aspiration catheter according to any one of claims 1 to 4, wherein the outer edge of the liquid aspiration port has an inclined portion, and the distal end of the inclined portion is located closer to the first lumen than the proximal end of the inclined portion.

6. The bile aspiration catheter according to any one of claims 1 to 5, wherein in a cross section perpendicular to the longitudinal direction of the shaft, the cross-sectional area of ​​the second lumen is greater than the cross-sectional area of ​​the first lumen.

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