Bile duct tube stent

Abstract

Provided is a bile duct tube stent excellent in visibility from the outside of a bile duct and capable of surely specifying the position of the bile duct by a simple procedure at the time of open surgery or laparoscopic surgery. A bile duct tube stent 1 to be placed in a bile duct comprises a flexible tube member 1T. A part or the whole of the tube member 1T contains a fluorescent dye that emits fluorescence in a predetermined wavelength region by irradiation with excitation light.

Description

Bile duct tube stent

[0001] The present invention relates to a biliary tube stent that is placed in the bile duct.

[0002] Laparoscopic cholecystectomy, which uses a laparoscope to remove the gallbladder, is known. Laparoscopic cholecystectomy is one of the most commonly performed surgical procedures in the field of abdominal surgery. While cholecystectomy is not particularly difficult, there are cases where complications arise from the procedure, and the postoperative mortality rate is not low. It has been revealed that bile duct injury is a common complication of laparoscopic cholecystectomy, and that fatal injury is not uncommon.

[0003] To reduce the risk of bile duct injury, it is necessary to perform the procedure while avoiding the bile duct, and for this purpose, it is important to identify the location of the bile duct during the procedure.

[0004] A known method for identifying the position of the bile duct is, for example, intraoperative cholangiography using X-ray fluoroscopy. In intraoperative cholangiography using X-ray fluoroscopy, a bile duct tube stent is placed in the bile duct, and the position of the bile duct in which the bile duct tube stent is placed can be determined under X-ray fluoroscopy. Intraoperative cholangiography is useful when the anatomical positions of the common bile duct and cystic duct cannot be determined during surgery.

[0005] Another known method for identifying the location of the bile duct is cholangiography using a fluorescent reagent containing a fluorescent dye that emits fluorescence in the near-infrared region, such as ICG (indocyanine green). In cholangiography using a fluorescent reagent, the fluorescent reagent is administered intravenously before surgery, and the fluorescence emitted by the fluorescent dye that is contained in the bile as a result of the administration is imaged with a near-infrared camera, thereby making it possible to identify the location of the bile duct through which bile flows.

[0006] Conventionally, drainage (stent placement) has been commonly performed by placing a tube stent through an endoscope to drain fluid from a body cavity. Known examples of tube stents used in stent placement include the tube stent disclosed in Patent Document 1 listed below.

[0007] The tube stent disclosed in Patent Document 1 is made of a flexible tubular member and is composed of a straight body portion having an approximately straight shape, a distal end curved portion having a curved shape connected to one end of the straight body portion, and a proximal end curved portion having a curved shape connected to the other end of the straight body portion, with a distal end through-hole provided at a position where the approximate central axis of the lumen formed within the straight body portion intersects with the peripheral wall of the distal end curved portion, and a proximal end through-hole provided at a position where the approximate central axis of the lumen formed within the straight body portion intersects with the peripheral wall of the proximal end curved portion.

[0008] Japanese Patent Application Laid-Open No. 2021-186190

[0009] The above-mentioned intraoperative cholangiography using X-ray fluoroscopy has the advantage that the visibility of the bile duct can be ensured through X-ray fluoroscopic images. However, it requires the preparation of an X-ray fluoroscopic imaging device and the patient and medical staff to wear X-ray protective gear when performing laparoscopic surgery, which results in problems such as large scale implementation, high cost, and labor; the need for personnel and time to take X-ray fluoroscopic images; and exposure of the patient and medical staff to X-rays.

[0010] Furthermore, while the above-mentioned cholangiography using fluorescent reagents has the advantage of requiring only a simple procedure of intravenous injection of the fluorescent reagent before surgery, it has problems such as poor visibility of the bile duct due to insufficient fluorescence performance.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a bile duct tube stent that has excellent visibility from the outside of the bile duct, allowing the position of the bile duct to be reliably identified with a simple procedure during open surgery or laparoscopic surgery.

[0012] In order to achieve the above-mentioned object, the bile duct tube stent of the present invention is a bile duct tube stent that is placed in the bile duct, and is characterized in that it consists of a flexible tubular member, and part or all of the tubular member contains a fluorescent dye that emits fluorescence in a predetermined wavelength range when irradiated with excitation light.

[0013] According to the above configuration, the bile duct tube stent is made of a flexible tube member, and part or all of the tube member contains a fluorescent dye.Therefore, the position of the bile duct tube stent placed within the bile duct can be identified by visually observing the fluorescence emitted by the fluorescent dye, and a bile duct tube stent with excellent visibility from outside the bile duct can be provided.

[0014] For example, in laparoscopic cholecystectomy, by placing a bile duct tube stent in the bile duct beforehand, the location of the bile duct can be accurately identified and the gallbladder can be removed while avoiding the bile duct, thereby reducing the risk of bile duct damage.

[0015] Furthermore, for example, in bile duct resection, in which the bile duct is removed using a laparoscope, by placing a bile duct tube stent in the bile duct beforehand, the position of the bile duct to be removed can be accurately identified and approached, reducing the risk of damaging other organs.

[0016] In the bile duct tube stent according to the present invention, in the above-mentioned configuration, the tube member may have a spiral portion formed in a spiral shape in the longitudinal direction, and the spiral portion may be configured to contain the fluorescent dye.

[0017] According to the above configuration, when the bile duct tube stent is placed in the bile duct, the spiral portion containing the fluorescent dye is positioned so as to be pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0018] In the bile duct tube stent according to the present invention, in the above-mentioned configuration, the tube member may have a wavy portion formed in a wavy shape in the longitudinal direction, and the wavy portion may be configured to contain the fluorescent dye.

[0019] According to the above configuration, when the bile duct tube stent is placed in the bile duct, the wavy portion containing the fluorescent dye is positioned so as to be pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0020] In the bile duct tube stent of the present invention, in the above configuration, the tube member may have flap portions at one or both ends of the tube member, and the flap portions may be configured to protrude radially relative to the circumferential surface of the tube member.

[0021] According to the above configuration, when the bile duct tube stent is placed in the bile duct, the flaps protruding radially from the circumferential surface of the tube member abut against the inner wall of the bile duct or the inner wall of an organ outside the bile duct, restricting longitudinal movement of the tube member, thereby fixing the position of the bile duct tube stent and preventing migration (dislocation).Furthermore, the flaps can be formed by cutting into the circumferential surface of the tube member, making it possible to prevent migration of the bile duct tube stent with a simple configuration.

[0022] In the bile duct tube stent according to the present invention, in the above configuration, the tube member may have a flared portion at one or both ends of the tube member, and the flared portion may be configured to expand radially relative to the circumferential surface of the tube member.

[0023] According to the above configuration, when the bile duct tube stent is placed in the bile duct, the flared portion that expands radially relative to the circumferential surface of the tube member abuts against the inner wall of the bile duct or the inner wall of an organ outside the bile duct, restricting longitudinal movement of the tube member, thereby fixing the position of the bile duct tube stent and preventing migration. Furthermore, the flared portion can be formed by cutting a notch into the end of the tube member, making it possible to prevent migration of the bile duct tube stent with a simple configuration.

[0024] FIG. 1 is a perspective view showing a bile duct tube stent according to an embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of the bile duct tube stent shown in FIG. 1. FIG. 3 is a plan view showing an example of a tube stent delivery device for placing a bile duct tube stent according to an embodiment of the present invention in a bile duct. FIG. 4 is a plan view showing an inner sheath of the tube stent delivery device shown in FIG. 3. FIG. 5 is a plan view showing an outer sheath of the tube stent delivery device shown in FIG. 3. FIG. 6 is a schematic view showing how a bile duct tube stent according to an embodiment of the present invention is placed in a bile duct. FIG. 7 is a perspective view showing a tube stent which is a first derivative example of an embodiment of the present invention. FIG. 8 is a perspective view showing a tube stent which is a second derivative example of an embodiment of the present invention. FIG. 9 is a perspective view showing a tube stent which is a third derivative example of an embodiment of the present invention.

[0025] Hereinafter, a bile duct tube stent according to an embodiment of the present invention will be described with reference to the drawings. In this specification, the inside of the patient's body is defined as the distal side, and the side closest to the user is defined as the proximal side, based on the user of the endoscope. The drawings referred to in this specification are not necessarily to scale with respect to actual dimensions, and some parts are exaggerated or simplified to schematically illustrate the configuration according to the present invention.

[0026] First, the configuration of a bile duct tube stent 1 in this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a perspective view showing a bile duct tube stent 1 in an embodiment of the present invention. Figure 2 is a longitudinal cross-sectional view of the bile duct tube stent 1 shown in Figure 1.

[0027] The bile duct tube stent 1 (hereinafter referred to as tube stent 1) in this embodiment is used not only to improve bile flow by being placed in the bile duct, but also as a marker to indicate the position of the bile duct during open surgery or laparoscopic surgery.

[0028] The tube stent 1 in this embodiment is made of a flexible tube member 1T. The tube stent 1 is produced by processing the tube member 1T into a predetermined shape, and is generally configured to include a straight body portion 11 having a substantially linear shape, a distal end portion 12 communicating with the distal end of the straight body portion 11, and a proximal end portion 13 communicating with the proximal end of the straight body portion 11. As will be described later, a part or the entire tube member 1T is configured to contain a fluorescent dye that emits fluorescence in a predetermined wavelength range when irradiated with excitation light.

[0029] The straight body portion 11 is located at the center of the tube stent 1, extending in the longitudinal direction of the flexible tubular member 1T that constitutes the tube stent 1. The straight body portion 11 is configured to have a substantially linear shape in its natural state when no external load is applied. Note that the straight body portion 11 may have a curved shape that matches the shape of the bile duct.

[0030] The distal end portion 12 is the end portion of the flexible tubular member 1T constituting the tube stent 1 that is positioned deep inside the bile duct when the tube stent 1 is placed in the bile duct. One end of the distal end portion 12 is connected to the straight body portion 11. The other end of the distal end portion 12 is a free end, the end surface of which constitutes the distal end surface 2 of the tube stent 1, and which has a distal end opening 2a where the lumen 5 of the tubular member 1T constituting the tube stent 1 opens.

[0031] In the illustrated configuration, the distal end 12 is formed to have a substantially straight shape in a natural state without an external load, but may be formed into a curved shape such as a pigtail shape or an α-loop shape. When the distal end 12 is curved, the distal end 12 may be curved with a substantially uniform curvature (a substantially perfect circle), or may be curved only partially or with partially different curvatures.

[0032] The proximal end portion 13 is the end portion of the flexible tubular member 1T constituting the tube stent 1 that is positioned on the duodenal side when the tube stent 1 is placed in the bile duct. One end of the proximal end portion 13 is connected to the straight body portion 11. The other end of the proximal end portion 13 is a free end, the end face of which constitutes the proximal end face 3 of the tube stent 1, and which has a proximal end opening 3a where the lumen 5 of the tubular member 1T constituting the tube stent 1 opens.

[0033] In the illustrated configuration, the proximal end 13 is formed to have a substantially straight shape in a natural state without external load, but it may also be formed into a curved shape, such as a pigtail shape or an alpha loop shape. When the proximal end 13 is curved, the proximal end 13 may be curved with substantially the same curvature (a substantially perfect circle), or may be curved only partially or with partially different curvatures. Note that the distal end 12 and the proximal end 13 may each have an independent shape; for example, one may be substantially straight and the other may be curved.

[0034] The tube stent 1 has a size that allows it to be placed in the bile duct of a patient, and various sizes may be prepared depending on the patient's physique, etc. As an example, the approximate longitudinal dimension of the tube stent 1 is about 15 to 200 mm. The diameter (inner diameter) of the cross section of the lumen within the tubular member 1T that constitutes the tube stent 1 is a size that allows the inner sheath 121 of the tube stent delivery device 100 (described later) to be inserted into the lumen 5 of the tube stent 1, and is, for example, about 1.0 to 5.0 mm.

[0035] A flap portion 21 is provided at the distal end portion 12. The flap portion 21 is formed by cutting a portion of the circumferential wall of the tubular member 1T so as to expose the lumen 5 of the tubular member 1T, and has a base end portion 21a connected to the tubular member 1T and a tip end portion 21b protruding from the base end portion 21a. The base end portion 21a is located distal to the tubular member 1T relative to the tip end portion 21b. The tip end portion 21b is bent so as to expand radially outward from the circumferential surface of the tubular member 1T, and is capable of moving in directions away from or toward the circumferential surface of the tubular member 1T. An opening 23 is formed radially inward of the tip end portion 21b, exposing the lumen 5 inside the tubular member 1T.

[0036] The size of the flap portion 21 is not particularly limited, but for example, it is preferable that the opening area of ​​the opening 23 formed by the flap portion 21 is approximately equal to or greater than the cross-sectional area of ​​the tube lumen 5. The angle of the flap portion 21 protruding from the base end portion 21a to the tip end portion 21b relative to the tubular member 1T (the angle formed by the flap portion 21) is not particularly limited as long as it protrudes from the base end portion 21a toward the tip end portion 21b so as to move away from the opening 23. The position of the flap portion 21 is also not particularly limited, and the flap portion 21 can be formed at any position proximal to the distal end surface 2 of the tube stent 1 at the distal end portion 12.

[0037] A flap portion 31 is provided at the proximal end 13. Similar to the flap portion 21 at the distal end 12, the flap portion 31 is formed by cutting a portion of the circumferential wall of the tubular member 1T so as to expose the lumen 5 of the tubular member 1T, and has a base end 31a connected to the tubular member 1T and a tip end 31b protruding from the base end 31a. The base end 31a is located closer to the proximal side of the tubular member 1T than the tip end 31b. The tip end 31b is bent so as to expand radially outward from the circumferential surface of the tubular member 1T, allowing it to move in directions away from or toward the circumferential surface of the tubular member 1T. An opening 33 is formed radially inward of the tip end 31b, exposing the lumen 5 inside the tubular member 1T.

[0038] The size of the flap portion 31 is not particularly limited, but for example, it is preferable that the opening area of ​​the opening 33 formed by the flap portion 31 is approximately equal to or greater than the cross-sectional area of ​​the tube lumen 5. The angle of the flap portion 31 protruding from the base end portion 31a to the tip end portion 31b with respect to the tubular member 1T (the angle formed by the flap portion 31) is not particularly limited as long as it protrudes from the base end portion 31a toward the tip end portion 31b so as to move away from the opening 33. The position of the flap portion 31 is also not particularly limited, and the flap portion 31 can be formed at any position distal to the proximal end surface 3 of the tube stent 1 at the proximal end portion 13.

[0039] The flap portions 21, 31 are provided to protrude from the circumferential surface of the tube member 1T and serve as movement-restricting members that restrict migration (displacement) of the tube stent 1 when the tube stent 1 is placed in the bile duct. The flap portion 21 formed at the distal end 12 functions as a stopper that abuts against the inner wall of the bile duct to prevent longitudinal movement of the tube member 1T. The flap portion 31 formed at the proximal end 13 functions as a stopper that interferes with (abuts against) the inner wall of the duodenum or bile duct to prevent the tube stent 1 from being drawn into the bile duct. As a result, the flap portions 21, 31 stabilize the placement of the tube stent 1. The flap portions 21, 31 are arranged to cover the upper sides (radially outward of the tube member 1T) of the openings 23, 33, respectively, and serve as foreign body intrusion prevention members that prevent foreign bodies from entering the lumen 5 of the tube member 1T through the openings 23, 33.

[0040] The openings 23 and 33 formed by the flap portions 21 and 31 serve as a flow path for bile through the tube stent 1 .

[0041] When the tube stent 1 is placed in the bile duct, the distal end opening 2a, where the lumen 5 of the tube member 1T opens at the distal end surface 2, and the opening 23 formed by the flap portion 21 are positioned in the bile duct. This allows bile in the bile duct to flow into the tube stent 1 through the distal end opening 2a and the opening 23 formed by the flap portion 21.

[0042] Furthermore, when the tube stent 1 is placed in the bile duct, the proximal end opening 3a where the lumen 5 of the tube member 1T opens at the proximal end surface 3 and the opening 33 formed by the flap portion 31 are positioned in the duodenum 161. This allows bile flowing through the lumen 5 inside the tube stent 1 to flow into the duodenum 161 through the opening 33 formed by the flap portion 31 in addition to the proximal end opening 3a.

[0043] In the illustrated configuration, flap portions 21, 31 are provided on both the distal end portion 12 and the proximal end portion 13, but they may be provided on only one of the distal end portion 12 and the proximal end portion 13, or the configuration may be such that flap portions 21, 31 are not provided on either the distal end portion 12 or the proximal end portion 13.

[0044] The tube stent 1 is also provided with an endoscopic marker 41. The endoscopic marker 41 is not particularly limited, but may be formed, for example, as shown in the figure, by coloring a portion of the circumferential surface of the tube member 1T in a ring shape. The endoscopic marker 41 is preferably provided, for example, at a position distal to the flap portion 31 provided at the proximal end portion 13. This makes it easy to confirm the positions of the proximal end portion 13 and the flap portion 31 of the tube stent 1 under endoscopic images, allowing for accurate and easy positioning when placing the tube stent 1 in the bile duct.

[0045] The tube stent 1 in this embodiment is configured such that a part or the whole of the tube member 1T contains a fluorescent dye that emits fluorescence in a predetermined wavelength range when irradiated with excitation light. The fluorescent dye may be contained in only a part of the tube member 1T, or the whole tube member 1T may contain the fluorescent dye.

[0046] The fluorescent dye is preferably one that emits fluorescence in the red or near-infrared wavelength range of 600 to 1400 nm. Light in this wavelength range is highly permeable to human tissues such as skin, fat, and muscle, and can easily penetrate up to about 5 to 20 mm below the surface of living tissue.

[0047] Examples of fluorescent dyes that emit fluorescence in the above-mentioned wavelength ranges include water-soluble dyes such as riboflavin, thiamine, NADH (reduced nicotinamide adenine dinucleotide), and ICG (indocyanine green), as well as oil-soluble dyes such as the azo-boron complex compounds described in JP 2011-162445 A. Among these, dyes that are highly compatible with polymeric materials are preferred because they are stably retained in polymeric materials without eluting in vivo, and the azo-boron complex compounds described in JP 2011-162445 A are particularly preferred because they have excellent fluorescence emission intensity, compatibility with polymeric materials, light resistance, and heat resistance.

[0048] The tube member 1T containing a fluorescent dye is preferably formed from a polymeric material composition containing the fluorescent dye. The preferred concentration of the fluorescent dye in the polymeric material composition containing the fluorescent dye varies depending on the type of fluorescent dye and the polymeric material used as a binder, but is typically preferably 0.1 to 0.001% by mass.

[0049] The polymeric material to be doped with the fluorescent dye may be polyurethane, polypropylene, polyethylene, polyvinyl chloride, polyamide, polyamide elastomer, or the like, optionally containing a hardener.

[0050] One method for incorporating a fluorescent dye into a polymeric material is to knead the fluorescent dye into the polymeric material using a twin-screw kneader. The resulting polymeric material composition containing the fluorescent dye can be extrusion-molded or injection-molded into a tube to obtain a tube member 1T containing the fluorescent dye. Alternatively, the tube member 1T may be molded so that only a portion of the tube member 1T contains the fluorescent dye. Alternatively, a polymeric material containing no fluorescent dye may be extrusion-molded or injection-molded to obtain the tube member 1T, and then a component containing the fluorescent dye may be attached to the tube member 1T by adhesive, insert molding, or other means.

[0051] If necessary, a radiopaque contrast agent such as barium sulfate may be added to the polymeric material composition containing the fluorescent dye. This allows the tube stent 1 to be tracked by checking the radiopaque contrast agent contained in the tube member 1T under X-ray fluoroscopy, even if the tube stent 1 placed in the body moves away from the desired position in the bile duct.

[0052] The circumferential surface of the tube member 1T may be coated with paint containing a fluorescent dye, or a film-like member formed of a polymer material composition containing a fluorescent dye may be wound around the circumferential surface of the tube member 1T and adhesively fixed thereto.

[0053] Next, a tube stent delivery device 100 for placing a tube stent 1 in a bile duct according to an embodiment of the present invention will be described with reference to Figures 3 to 5. Figure 3 is a plan view showing an example of a tube stent delivery device 100 for placing a tube stent 1 in a bile duct according to an embodiment of the present invention. Figure 4 is a plan view showing an inner sheath 121 of the tube stent delivery device 100 shown in Figure 3, and Figure 5 is a plan view showing an outer sheath 122 of the tube stent delivery device 100 shown in Figure 3.

[0054] The tube stent delivery device 100 shown in Figure 3 is a medical treatment tool used to place a tube stent 1 in a bile duct, and is an endoscopic device that inserts the tube stent 1 into the bile duct via a forceps channel (treatment tool guide tube) of an endoscope 200, as shown in Figure 6 described below.

[0055] The tube stent delivery device 100 shown in Fig. 3 is generally configured to include a long and slender catheter portion 120 that is inserted into a patient's bile duct through a forceps channel of an endoscope 200, an operating portion 130 that is connected to the proximal side of the catheter portion 120 and is used to operate the catheter portion 120 from outside the body, a guide wire 140, and a tube stent 1 that is to be placed. The catheter portion 120 is located on the distal side of the tube stent delivery device 100 that is inserted into the patient's body, and the operating portion 130 is located on the proximal side that grasps and operates the tube stent delivery device 100 outside the patient's body.

[0056] The catheter portion 120 includes an inner sheath (inner tube) 121 having a distal end and a proximal end, and an outer sheath (outer tube) 122 having a distal end and a proximal end. Radiopaque markers (not shown) may be attached near the distal ends of the inner sheath 121 and the outer sheath 122. The radiopaque markers are position detection markers that can be confirmed under X-ray fluoroscopy when the catheter portion 120 is inserted into the patient's body, and are formed from, for example, a metal material such as gold, platinum, or tungsten, or a polymer material blended with barium sulfate or bismuth oxide.

[0057] The inner sheath 121 is made of a flexible, elongated tube. A guide wire 140 is inserted through the lumen of the inner sheath 121. The guide wire 140 is used as a guide for inserting the tube stent delivery device 100 into the patient's body. After inserting the guide wire 140 into the body to secure a path between the inside and outside of the body, the catheter portion 120 is advanced along the guide wire 140 inserted through the inner sheath 121, thereby allowing the distal side of the catheter portion 120 to be inserted into a target site inside the body. The outer diameter of the inner sheath 121 is approximately 0.5 to 4.0 mm.

[0058] A tapered tip section 123 that tapers toward the distal side (tip side) is formed at the distal end of the inner sheath 121. Note that instead of the tapered tip section 123, a tip tip having a similar tapered shape may be prepared separately from the inner sheath 121 and attached to the distal end of the inner sheath 121.

[0059] The outer sheath 122 is made of a flexible, elongated tube. The outer sheath 122 has an inner diameter slightly larger than the outer diameter of the inner sheath 121, and the inner sheath 121 is inserted inside the outer sheath 122 so as to be relatively slidable. For example, the inner diameter of the outer sheath 122 is approximately 0.5 to 4.5 mm, and the outer diameter of the outer sheath 122 is approximately 1.0 to 5.0 mm. An operating unit 130 is connected to the proximal end of the outer sheath 122, and when a user operates a connector 131 of the operating unit 130, the inner sheath 121 is slidable in the axial direction relative to the outer sheath 122.

[0060] Examples of materials that can be used for the inner sheath 121 and the outer sheath 122 include various resin materials such as polyolefins such as polyethylene and polypropylene, polyesters such as polyvinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, polyethylene terephthalate and polybutylene terephthalate, polyamide, polyether polyamide, polyester polyamide, polyether ether ketone, polyetherimide, fluorine-based resins such as polytetrafluoroethylene and tetrafluoroethylene-hexafluoropropylene copolymer, and various thermoplastic elastomers such as polystyrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, and polybutadiene-based. Two or more of these materials can also be used in combination.

[0061] The operation unit 130 includes a connector 131 and a connector 133. As shown in Fig. 4, the connector 131 is connected and fixed to the proximal end of the inner sheath 121. Furthermore, as shown in Fig. 5, the connector 133 is connected and fixed to the proximal end of the outer sheath 122. The connector 131 has a through-hole that passes through in the axial direction, and this through-hole communicates with the inner lumen of the inner sheath 121. The connector 133 has a through-hole that passes through in the axial direction, and this through-hole communicates with the inner lumen of the outer sheath 122. The distal end of the connector 131 and the proximal end of the connector 133 can be coupled and released from each other by a luer lock system or the like.

[0062] The guide wire 140 is inserted through the lumen of the inner sheath 121 over the entire length thereof. The distal end of the guide wire 140 can protrude from the tapered tip portion 123 of the inner sheath 121, and the proximal end of the guide wire 140 can be exposed to the outside through the through-hole of the connector 131.

[0063] When inserting the tube stent delivery device 100 into a patient's body, the tube stent 1 is attached to the distal side of the tube stent delivery device 100 as shown in Fig. 3. Specifically, the distal end of the inner sheath 121 is inserted inside the tube stent 1, and the proximal end surface 3 of the tube stent 1 is positioned so as to abut against the distal end surface 122a of the outer sheath 122 through which the inner sheath 121 has been inserted. In this manner, the tube stent 1 is positioned in series with the outer sheath 122, with the inner sheath 121 inserted inside it. Note that if the tube stent 1 has a curved portion, the tube stent 1 attached to the distal side of the tube stent delivery device 100 will be elastically deformed to match the shape of the inner sheath 121.

[0064] An example of a procedure for placing the tube stent 1 in the bile duct according to this embodiment will be described below with reference to Fig. 6. Fig. 6 is a diagram schematically illustrating the placement of the tube stent 1 in the bile duct according to this embodiment. Fig. 6 shows a patient's duodenum 161, duodenal papilla 162, and common bile duct (bile duct) 163.

[0065] When placing the tube stent 1 in the bile duct, first, the endoscope 200 is inserted to the vicinity of the duodenal papilla 162, and the guide wire 140 is passed through the forceps channel of the endoscope 200 into the common bile duct 163. Next, the connectors 131 and 133 are joined together, and with the tube stent 1 attached to the distal end of the inner sheath 121, the catheter portion 120 is advanced along the guide wire 140.

[0066] While checking the positions of the inner sheath 121 and the outer sheath 122, the tube stent 1 is inserted to an appropriate position in the common bile duct 163. At this time, the positions of the X-ray contrast markers attached near the distal ends of the inner sheath 121 and the outer sheath 122 may be checked under X-ray fluoroscopy, or the position of the endoscopic marker 41 on the tube stent 1 may be checked under endoscopic images.

[0067] Thereafter, the connectors 131 and 133 are released from the connection, and the inner sheath 121 is slid proximally and withdrawn while maintaining the position of the outer sheath 122. At this time, as shown in Figure 6, the distal end surface 122a of the outer sheath 122 abuts against the proximal end surface 3 of the tube stent 1, and the inner sheath 121 can be withdrawn from the lumen 5 of the tube stent 1 while maintaining the tube stent 1 in an appropriate position within the common bile duct 163, and the tube stent 1 can be placed within the common bile duct 163.

[0068] In this embodiment, as shown in FIG. 6 , a tube stent 1 can be delivered to the interior of a bile duct and placed therein using an endoscope 200 and a tube stent delivery device 100. The tube stent 1 is placed in the bile duct with its circumferential surface pressed against the inner wall of the bile duct. As a result, when excitation light is irradiated onto the bile duct from outside during thoracotomy, laparotomy, or laparoscopic surgery, the irradiated light is absorbed by a fluorescent dye contained in a part or all of the tubular member 1T, causing the fluorescent dye to emit fluorescence. The fluorescence emitted from a part or all of the tubular member 1T is emitted to the outside of the bile duct, allowing the positions of the tube stent 1 and the bile duct to be clearly visualized from outside the bile duct. As a result, it is possible to identify the position of the bile duct, avoid bile duct damage that may occur during laparoscopic cholecystectomy, and accurately identify the location of the bile duct to be removed during bile duct removal. The fluorescence emitted from a part or the whole of the tube member 1T may be visually recognized using an image captured by an imaging device such as a near-infrared camera according to the wavelength of the fluorescence.

[0069] Furthermore, when the tube stent 1 is placed in the bile duct in this manner, bile flows into the lumen 5 of the tube stent 1 through the distal end opening 2a opened at the distal end surface 2 and the opening 23 formed by the flap portion 21, and flows out into the duodenum 161 through the proximal end opening 3a opened at the proximal end surface 3 and the opening 33 formed by the flap portion 31, thereby improving the flow of bile.

[0070] Furthermore, when the tube stent 1 is placed in the bile duct in this manner, the flap portions 21, 31 protruding radially from the circumferential surface of the tubular member 1T abut and engage with the inner wall of the bile duct or the inner wall of the duodenum 161 outside the bile duct, thereby restricting longitudinal movement of the tubular member 1T and fixing the position of the tube stent 1 to prevent migration. The flap portions 21, 31 can be formed by making cuts in the circumferential surface of the tubular member 1T, thereby preventing migration of the tube stent 1 with a simple configuration. Furthermore, the flap portions 21, 31 are positioned so as to cover the upper sides of the openings 23, 33, respectively, thereby preventing foreign matter from entering the lumen 5 of the tubular member 1T through the openings 23, 33.

[0071] (First Derivative Example) A tube stent 1a which is a first derivative example of an embodiment of the present invention will be described with reference to Fig. 7. Fig. 7 is a perspective view showing a tube stent 1a which is a first derivative example of an embodiment of the present invention.

[0072] The tube stent 1 in the above-described embodiment is configured with a substantially linear straight body portion 11. In contrast, as shown in Fig. 7, a tube stent 1a in a first derivative example is configured with a helical portion 11a formed by spiraling the tube member 1T in the longitudinal direction instead of the straight body portion 11, and the helical portion 11a may be configured to contain the above-described fluorescent dye. Note that the helical portion 11a may be provided over the entire area between the distal end portion 12 and the proximal end portion 13, or only a portion between the distal end portion 12 and the proximal end portion 13 may be formed helically, with the remaining portion being formed substantially linearly or in a wavy shape as described below.

[0073] As a result, when the tube stent 1a is placed in the bile duct, the spiral portion 11a containing the fluorescent dye is positioned so as to be pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0074] (Second Variant) A tube stent 1b, which is a second variant of the embodiment of the present invention, will be described with reference to Fig. 8. Fig. 8 is a perspective view showing a tube stent 1b, which is a second variant of the embodiment of the present invention.

[0075] The tube stent 1 in the above-described embodiment is configured with a substantially linear straight body portion 11. In contrast, as shown in Fig. 8, a tube stent 1b in a second derivative example is configured with a wavy portion 11b in which the tube member 1T is formed in a wavy shape in the longitudinal direction instead of the straight body portion 11, and the wavy portion 11b may be configured to contain the above-described fluorescent dye. Note that the wavy portion 11b may be provided over the entire area between the distal end portion 12 and the proximal end portion 13, or only a portion between the distal end portion 12 and the proximal end portion 13 may be formed in a wavy shape, with the remaining portion being formed in a substantially linear shape or the above-described spiral shape.

[0076] As a result, when the tube stent 1b is placed in the bile duct, the wavy portion 11b, which contains a fluorescent dye, is positioned so that it is pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0077] (Third Variant) A tube stent 1c, which is a third variant of the embodiment of the present invention, will be described with reference to Fig. 9. Fig. 9 is a perspective view showing a tube stent 1c, which is a third variant of the embodiment of the present invention.

[0078] The tube stent 1 in the above-described embodiment has a flap portion 21 formed at the distal end 12 and a flap portion 31 formed at the proximal end 13. In contrast, as shown in Figure 9, a tube stent 1c in a third derivative example has a flared portion 71 formed at the distal end 12 and a flared portion 81 formed at the proximal end 13 instead of the flap portions 21 and 31.

[0079] The flared portion 71 is formed, for example, by a plurality of notches 71c cut along the longitudinal direction from the distal end surface 2 of the tube stent 1c, and has a base end 71a connected to the tubular member 1T and a tip end 71b corresponding to the position of the distal end surface 2. The tip end 71b is formed so as to expand radially outward from the circumferential surface of the tubular member 1T, and is capable of moving in a direction away from or toward the circumferential surface of the tubular member 1T.

[0080] The flared portion 81 is formed, for example, by a plurality of notches 81c cut along the longitudinal direction from the proximal end surface 3 of the tube stent 1c, and has a base end 81a connected to the tube member 1T and a tip end 81b corresponding to the position of the proximal end surface 3. The tip end 81b is formed so as to expand radially outward from the circumferential surface of the tube member 1T, and is capable of moving in a direction away from or toward the circumferential surface of the tube member 1T.

[0081] By providing flared portions 71, 81 at the distal end 12 and proximal end 13 of the tube stent 1c in this manner, when the tube stent 1c is placed in the bile duct, the flared portions 71, 81 expand radially relative to the circumferential surface of the tube member 1T and abut against and engage with the inner wall of the bile duct or the inner wall of an area outside the bile duct, such as the duodenum 161, thereby restricting longitudinal movement of the tube member 1T and fixing the position of the tube stent 1c to prevent migration. Furthermore, the flared portions 71, 81 can be formed by making cuts from the end face of the tube member 1T, thereby preventing migration of the tube stent 1c with a simple configuration.

[0082] In the illustrated configuration, the flared portions 71, 81 are provided at both the distal end portion 12 and the proximal end portion 13, but they may be provided at only one of the distal end portion 12 and the proximal end portion 13. Also, as in the tube stent 1 described above, the flared portions 71, 81 may be provided in addition to the flap portions 21, 31.

[0083] The operation of the tube stents 1, 1a, 1b, and 1c in the above-described embodiments will be described below.

[0084] The tube stents 1, 1a, 1b, and 1c in this embodiment are tube stents 1, 1a, 1b, and 1c that are placed in the bile duct, and are made of a flexible tube member 1T, and part or all of the tube member 1T is made up of a fluorescent dye that emits fluorescence in a predetermined wavelength range when irradiated with excitation light.

[0085] According to the above configuration, the tube stents 1, 1a, 1b, 1c are made of a flexible tube member 1T, and part or all of the tube member 1T is made to contain a fluorescent dye.Therefore, the position of the tube stents 1, 1a, 1b, 1c placed in the bile duct can be identified by visually observing the fluorescence emitted by the fluorescent dye, and tube stents 1, 1a, 1b, 1c with excellent visibility from outside the bile duct can be provided.

[0086] For example, in laparoscopic cholecystectomy, by placing tube stents 1, 1a, 1b, and 1c in the bile duct in advance, the position of the bile duct can be accurately identified and the gallbladder can be removed while avoiding the bile duct, thereby reducing the risk of bile duct damage.

[0087] Furthermore, for example, in a bile duct resection in which the bile duct is resected using a laparoscope, by placing tube stents 1, 1a, 1b, and 1c in the bile duct in advance, the position of the bile duct to be resected can be reliably identified and approached, thereby reducing the risk of damaging other organs.

[0088] In the tube stent 1a of this embodiment, as shown in Figure 7, the tube member 1T has a spiral portion 11a formed in a spiral shape in the longitudinal direction, and the spiral portion 11a may be configured to contain a fluorescent dye.

[0089] According to the above configuration, when the tube stent 1a is placed in the bile duct, the spiral portion 11a containing the fluorescent dye is positioned so as to be pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0090] In the tube stent 1b of this embodiment, as shown in Figure 8, the tube member 1T has a wavy portion 11b formed in a wavy shape in the longitudinal direction, and the wavy portion 11b may be configured to contain a fluorescent dye.

[0091] According to the above configuration, when the tube stent 1b is placed in the bile duct, the wavy portion 11b containing the fluorescent dye is positioned so as to be pressed against the inner wall of the bile duct, thereby further improving the visibility of the fluorescence from outside the bile duct.

[0092] In the tube stents 1, 1a, and 1b of this embodiment, as shown in Figures 1 to 3, 7, and 8, the tube member 1T has flap portions 21, 31 at one or both ends of the tube member 1T, and the flap portions 21, 31 may be configured to protrude radially relative to the circumferential surface of the tube member 1T.

[0093] According to the above configuration, when the tube stent 1, 1a, 1b is placed in the bile duct, the flaps 21, 31 protruding radially from the circumferential surface of the tube member 1T abut against the inner wall of the bile duct or the inner wall of an organ outside the bile duct, restricting longitudinal movement of the tube member 1T, thereby fixing the position of the tube stent 1, 1a, 1b and preventing migration. Furthermore, the flap portions 21, 31 can be formed by cutting into the circumferential surface of the tube member 1T, making it possible to prevent migration of the tube stent 1, 1a, 1b with a simple configuration.

[0094] As shown in Figure 9, the tube stent 1c in this embodiment may have a tube member 1T having flared portions 71, 81 at one or both ends of the tube member 1T, and the flared portions 71, 81 may be configured to expand radially relative to the circumferential surface of the tube member 1T.

[0095] According to the above configuration, when the tube stent 1c is placed in the bile duct, the flared portions 71, 81 that expand radially relative to the circumferential surface of the tube member 1T abut against the inner wall of the bile duct or the inner wall of an organ outside the bile duct, restricting longitudinal movement of the tube member 1T, thereby fixing the position of the tube stent 1 and preventing migration. Furthermore, the flared portions 71, 81 can be formed by cutting notches into the ends of the tube member 1T, making it possible to prevent migration of the tube stent 1c with a simple configuration.

[0096] The above-described embodiments are provided to facilitate understanding of the present invention and are not intended to limit the present invention. The components disclosed in the above-described embodiments are intended to encompass all design modifications and equivalents that fall within the technical scope of the present invention. Furthermore, configurations obtained by appropriately combining the components described in each embodiment are also encompassed by the present invention.

[0097] REFERENCE SIGNS LIST 1, 1a, 1b, 1c Tube stent 1T Tube member 2, 122a Distal end surface 2a Distal end opening 3 Proximal end surface 3a Proximal end opening 5 Lumen 11 Straight body portion 11a Spiral portion 11b Wavy portion 12 Distal end portion 13 Proximal end portion 21, 31 Flap portion 21a, 31a, 71a, 81a Base end portion 21b, 31b, 71b, 81b Tip portion 23, 33 Opening 41 Endoscope marker 71, 81 Flare portion 71c, 81c Cut portion 100 Tube stent delivery device 120 Catheter portion 121 Inner sheath (inner tube) 122 Outer sheath (outer tube) 123 Tip tapered portion 130 Operation portion 131, 133 Connector 140 Guide wire 161 Duodenum 162 Duodenal papilla 163 Common bile duct (bile duct) 200 Endoscope

Claims

1. A bile duct tube stent to be placed in the bile duct, comprising a flexible tubular member, the entire or part of which contains a fluorescent dye that emits fluorescence in a predetermined wavelength range when irradiated with excitation light.

2. A bile duct tube stent as described in claim 1, characterized in that the tubular member has a spiral portion formed in a spiral shape in the longitudinal direction, and the spiral portion is configured to contain the fluorescent dye.

3. A bile duct tube stent as described in claim 1, characterized in that the tubular member has a wavy portion formed in a wavy shape in the longitudinal direction, and the wavy portion is configured to contain the fluorescent dye.

4. A bile duct tube stent as described in any one of claims 1 to 3, characterized in that the tubular member has a flap portion at one or both ends of the tubular member, and the flap portion is configured to protrude radially from the circumferential surface of the tubular member.

5. A bile duct tube stent as described in any one of claims 1 to 3, characterized in that the tubular member has a flared portion at one or both ends of the tubular member, and the flared portion is configured to expand radially relative to the circumferential surface of the tubular member.

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