Drainage tube and drainage tube separation mechanism

Abstract

The present invention is a drainage tube (1) for discharging a fluid to be discharged such as pus accumulated in an in-vivo gallbladder (11) to the exterior of the gallbladder (11), and comprises a preceding-stage tube (2) which is inserted in the gallbladder (11), and a subsequent-stage tube (3) which is bonded the end among the two ends of the preceding-stage tube (2) which is on the reverse side from the end that is inserted in the gallbladder (11), wherein the preceding-stage tube (2) and the subsequent-stage tube (3) are bonded together by fitting the interior surface of the subsequent-stage tube (3) over the exterior surface of the preceding-stage tube (2). There is also provided an push-out member which is used for separating the preceding-stage tube (2) from the subsequent-stage tube (3) and with which the end of the preceding-stage tube (2) on the reverse side from the end that is inserted in tissue is pushed out of the subsequent-stage tube (3).

Description

Drainage tube

[0001] The present invention relates to a drainage tube. This application claims priority to Japanese Patent Application No. 2022-004924, filed on January 17, 2022, the contents of which are incorporated herein by reference.

[0002] Conventionally, biliary drainage tubes have been used as piping to drain bile from the body or into the duodenum. Bile is a liquid produced in the liver and flows into the duodenum through the bile duct, gallbladder, and common bile duct. When this bile combines with pancreatic juice in the duodenum, it activates the digestive enzymes contained in the pancreatic juice, breaking down fats and proteins and facilitating their absorption by the intestine. Furthermore, since fatty acids produced when fats are broken down are difficult to absorb, bile also functions to convert these fatty acids into a form that is more easily absorbed.

[0003] However, there is a condition called obstructive jaundice, in which bile flow is blocked by gallstones or tumors. When bile flow is blocked, the flow of bile stagnates, but the liver continues to produce bile. When the amount of bile produced by the liver exceeds the amount flowing into the duodenum, bile is stored in the gallbladder. However, if the gallbladder becomes full, some of the bile produced in the liver will accumulate in the liver. While this bile fulfills the functions described above when it flows into the duodenum, accumulation in the liver destroys liver tissue, potentially leading to cirrhosis. Therefore, when biliary obstruction occurs, biliary decompression (drainage) is necessary to improve bile flow.

[0004] In addition, when acute cholecystitis develops and surgery is not possible, gallbladder drainage is required to drain bile and pus from the gallbladder. Gallbladder drainage can be performed by surgical percutaneous transhepatic drainage or endoscopic gallbladder drainage. In endoscopic gallbladder drainage, a tube or stent is placed through the stomach or duodenal wall and the gallbladder wall to create a bile channel.

[0005] When draining the biliary tract, there is a method of using an endoscope to place a tube in the biliary tract to form a bile flow path. A drainage tube used for draining the biliary tract includes, for example, a long external fistula tube and a short internal fistula tube detachably attached to the distal end of the external fistula tube, as shown in Patent Document 1. In this case, the rear tube and the front tube are connected by wrapping a detachment prevention part made of a material that dissolves in the body around them. Alternatively, they are fixed by a sheet-like member.

[0006] International Publication No. 2015 / 133333

[0007] In the drainage tube described in Patent Document 1 as described above, when a fall-off prevention part or a sheet-like member made of a material that dissolves in the body is used, it is not possible to separate the long external fistula tube (hereinafter referred to as the "post-stage tube") from the short internal fistula tube (hereinafter referred to as the "pre-stage tube") at any time.

[0008] For example, drainage fluid accumulated in an organ may be assumed to be pus, but because the viscosity of pus is not always constant, it is necessary to first dilute the pus. This necessitates the ability to control the timing of separation of the rear tube from the front tube, and there is room for improvement in this regard.

[0009] Furthermore, when using a sheet-like member or a fall-off prevention member made of a material that dissolves inside the body, the number of components increases, which creates the problem of making the drainage tube structure more complex.

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a drainage tube that employs a simple structure while being able to control the timing of separation of the rear tube and the front tube.

[0011] In order to solve the above problems and achieve the object, the present invention employs the following aspects: (1) A drainage tube according to a first aspect of the present invention is a drainage tube for discharging waste fluid such as pus that has accumulated in tissue within a body to the outside of the tissue, and is characterized in that it comprises an upstream tube that is inserted into the tissue and a downstream tube that is joined to one of both ends of the upstream tube that is opposite the end that is inserted into the tissue, and the upstream tube and the downstream tube are joined by fitting the inner surface of the downstream tube into the outer surface of the upstream tube.

[0012] (2) In the drainage tube described in (1) above, it is preferable that an extrusion member is provided which is used to separate the front tube from the rear tube and which extrudes the end of the front tube opposite the end inserted into the tissue from the rear tube.

[0013] (3) In the drainage tube described in (2) above, it is preferable that the pusher member be capable of pushing the front tube in while inserted into the rear tube.

[0014] (4) In the drainage tube described in (2) above, it is preferable that the extrusion member is arranged to be capable of moving the rear tube in a direction away from the front tube while being engaged with the circumferential surface of the front tube.

[0015] (5) In the drainage tube described in any one of (1) to (3) above, an electrically-conductive wire having an outer diameter smaller than the inner diameter of the front tube and capable of forming a perforation in the tissue at its tip by passing a high-frequency current through it may be inserted into the front tube and the rear tube.

[0016] (6) In the drainage tube described in any one of (1) to (3) above, it is preferable that the tissue in the body is one or more tissues selected from the gallbladder, bile duct, abscess, and digestive tract.

[0017] (7) In the drainage tube described in any one of (1) to (4) above, it is preferable that the latter tube is led out to the outside of the body, and that a diluent is injected from outside the body via the latter tube and the former tube into the tissue inside the body and mixed with the drained liquid, and then the mixture of the drained liquid and the diluent can be led out of the body via the former tube and the latter tube.

[0018] (8) The drainage tube described in (7) above may be characterized in that after the injection of the diluent and the discharge of the mixture outside the body are performed one or more times, the rear tube can be separated from the front tube.

[0019] According to the drainage tubes according to the various aspects of the present invention, the timing of separation of the rear tube and the front tube can be controlled.

[0020] 7 is a side cross-sectional view showing an overall view of a drainage tube according to the present embodiment; FIG. 8 is a side cross-sectional view showing a joint portion between a rear tube and a front tube; FIG. 9 is a side cross-sectional view showing the shape of the front tube; FIG. 10 is a side cross-sectional view showing the shape of the front tube; FIG. 11 is a side cross-sectional view showing the shape of the front tube; FIG. 12 is a side cross-sectional view showing the shape of the front tube; FIG. 13 is a side cross-sectional view showing the shape of the front tube; FIG. 14 is a side cross-sectional view showing the configuration of a pusher member; FIG. 15 is a side cross-sectional view showing a state in which the drainage tube is not protruding from the endoscope; FIG. 16 is a side cross-sectional view showing a state in which the front tube is protruding from the tip of the endoscope using the operation unit in FIG. 17; FIG. 18 is a side cross-sectional view showing a state in which a current-carrying wire is inserted into the drainage tube to form a penetration in an organ wall; FIG. 19 is a side cross-sectional view of a main part showing a procedure for inserting a current-carrying wire ... showing a state in which a cleaning solution is injected into the gallbladder using a syringe. FIG. 1 is a side cross-sectional view showing a state in which a pusher member is inserted into a rear tube. FIG. 1 is a side cross-sectional view showing a state in which a mixed liquid of cleaning liquid and bile in the gallbladder is discharged to the outside of the body. FIG. 1 is a side cross-sectional view showing a procedure for separating the front tube and the rear tube by the pusher member ... according to a modified example. FIG. 1 is a side cross-sectional view showing a procedure for separating the front tube and the rear tube by the pusher member according to a modified example.

[0021] An example of a drainage tube according to an embodiment of the present invention will be described with reference to Figures 1 to 13. Figure 1 is an overall view of a drainage tube 1.

[0022] [Drainage Tube 1] As shown in Fig. 1, the drainage tube 1 is used to drain drainage fluid such as pus accumulated in one or more internal tissues selected from the gallbladder, bile duct, abscess, and digestive tract, for example, the gallbladder 11 (see Fig. 8), to the outside of the tissue. The drainage tube 1 is used by being inserted into an endoscope 100 (see Figs. 6 and 8). In this embodiment, the gallbladder 11 will be described below as a tissue.

[0023] As shown in FIGS. 1 and 2 , the drainage tube 1 comprises an upstream tube 2 and a downstream tube 3. The upstream tube 2 is inserted into the gallbladder 11 (see FIG. 8 ). The downstream tube 3 is joined to one of the ends of the upstream tube 2 (hereinafter referred to as the "first joining end 2b") opposite the end inserted into the gallbladder 11 (hereinafter referred to as the "distal end 2a"). The upstream tube 2 and downstream tube 3 are joined by fitting the inner surface 3c of the downstream tube 3 into the outer surface 2c of the upstream tube 2. The drainage tube 1 is provided with an operating unit 6 connected to the base end 3b of the downstream tube 3. The "joining" of the upstream tube 2 and downstream tube 3 includes a detachable engagement and further includes not only a state in which the entire joined portion of the upstream tube 2 and downstream tube 3 is in close contact with each other, but also a joined state in which there is a gap where the tubes are partially non-contacting with each other.

[0024] [Front-stage tube 2] The front-stage tube 2 is a short tube. The front-stage tube 2 has a length similar to that of an internal fistula tube (internal fistula stent) used in a typical internal fistula. Specifically, the front-stage tube 2 is formed to a length that allows the first joint end 2b of the front-stage tube 2 to protrude into the stomach or duodenum 12 near the gallbladder 11 when the front-stage tube 2 is placed in the gallbladder 11 (see FIG. 8 ). The length of the front-stage tube 2 is not particularly limited, but from the above-mentioned perspective, a length of 100 mm or more, preferably 120 mm or more, and usually 200 mm or less, preferably 150 mm or less is used.

[0025] The material of the front tube 2 can be, for example, a thermoplastic resin such as polyethylene (PE) or polypropylene (PP). The outer and inner diameters of the front tube 2 are preferably set to a size sufficient to allow drainage of drainage fluids such as pus accumulated in the gallbladder 11 when inserted into the gallbladder. The outer diameter of the front tube 2 is typically 1 mm or more, preferably 1.5 mm or more, and typically 3 mm or less, preferably 2 mm or less. More specifically, the outer diameter of the front tube 2 is, for example, approximately 1.66 mm (5 Fr). The inner diameter of the front tube 2 is typically 0.8 mm or more, preferably 1 mm or more, and typically 2.5 mm or less, preferably 2 mm or less, from the perspective of drainage of drainage fluids such as pus and ensuring the mechanical strength of the front tube. The front tube 2 can be made of a shape-memory material among the above-mentioned materials. For example, when the front tube 2 is curved (see front tube 2F shown in FIG. 3F ), ​​the front tube 2 extends straight with the current-carrying wire 4 (described later) inserted therethrough, and in this state the current-carrying wire 4 penetrates the organ wall of the gallbladder 11. The straightened front tube 2 then returns to its original shape when the current-carrying wire 4 is pulled out of the front tube 2.

[0026] The front tube 2 and the rear tube 3 may be joined by fitting the inner surface 3c of the rear tube 3 into the outer surface 2c of the front tube 2. The outer diameter of the front tube 2 is slightly larger than the inner diameter of the second joining end 3a of the rear tube 3. The outer diameter of the front tube 2 is smaller than the outer diameter of the rear tube 3. The inner diameter of the front tube 2 is smaller than the inner diameter of the rear tube 3. The front tube 2 is joined by frictional force generated when the first joining end 2b is pressed into and fitted into the second joining end 3a of the rear tube 3. Note that the present invention is not limited to this embodiment. The outer surface 2c of the front tube 2 and the inner surface 3c of the rear tube 3 may be joined with a constant joining force using frictional force or the like. In this embodiment, by appropriately selecting a combination of materials for the front tube 2 and the rear tube 3, the outer diameter of the front tube 2 and the inner diameter of the rear tube 3 can be made substantially the same. Furthermore, by using a material for the front tube 2 that expands at body temperature, it is possible to make the outer diameter of the front tube 2 smaller than the inner diameter of the rear tube 3.

[0027] The inner diameter of the front tube 2 is formed to a size that allows the insertion of the electric wire 4, which will be described later. The inner diameter of the front tube 2 is preferably a diameter that allows the bile to flow smoothly.

[0028] The front tube 2 has the function of being inserted into the gallbladder 11 and capable of draining drainage fluids such as pus. The shape of the front tube 2 is not particularly limited, but shapes such as those shown in FIGS. 3A to 3F can be adopted. The front tubes 2A, 2B, 2C, and 2D shown in FIGS. 3A to 3D have a curved portion 21 on one or both sides in the axial direction. The presence of such a curved portion 21 makes it easier to prevent the front tube 2 from slipping out or becoming lost when placed inside the body. The front tubes 2C, 2D, 2E, and 2F shown in FIGS. 3C to 3F have a first folded portion 22A (22) on the shaft portion 23 of the front tube 2 that engages when pulled in the axial direction of the drainage tube 1 in the direction opposite the insertion direction (downward in FIG. 3 ), to prevent the placed front tube 2 from slipping out. When the front tube 2 is inserted into the gallbladder 11, by providing a folded portion 22A that is folded back toward the organ wall of the tissue into which the front tube 2 is inserted (the mucosal layer, muscularis propria, subserosa, and serosa in the case of the gallbladder 11 of this embodiment), or a folded portion 22B that is folded back toward the organ wall of another tissue (stomach or duodenum 12) in which the end (first joint end 2b) of the front tube 2 opposite to folded portion 22A is located, it is possible to more easily prevent the front tube 2 placed inside the body from escaping, regardless of the tube shape.

[0029] 3F has a shape that more reliably prevents deviation by having the tip 23a of the shaft portion 23 rolled like a soft-serve ice cream. In this case, when the electric wire 4 (described later) is inserted into the front tube 2F, the soft-serve ice cream-shaped tip 23a extends linearly, and in this state the electric wire 4 penetrates the organ wall of the gallbladder 11. When the electric wire 4 is then pulled out of the front tube 2F, the straightened tip 23a of the front tube 2F returns to its original shape rolled like a soft-serve ice cream.

[0030] [Following Tube 3] As shown in Figures 1 and 2, the following tube 3 is a tube that is longer than the preceding tube 2. The following tube 3 may have a structure equivalent to that of a general external fistula tube. Specifically, the following tube 3 has a portion of a certain length where the preceding tube 2 is fitted (hereinafter referred to as the "second joining end 3a"). The length of the second joining end 3a is determined taking into consideration the joining strength of the preceding tube 2 and the following tube 3 and the ease of subsequent separation, but is typically set to 2 mm or more, preferably 3 mm or more, and typically 20 mm or less, preferably 10 mm or less, and more preferably 7 mm or less. Generally, a length of approximately 5 mm is sufficient.

[0031] The outer diameter of the front tube 2 is slightly larger than the inner diameter of the rear tube 3. The first joint end 2b of the front tube 2 is fitted into the second joint end 3a. When the first joint end 2b of the front tube 2 is fitted into the second joint end 3a, the second joint end 3a has a larger diameter than the inner diameter of the remaining portion of the rear tube 3 (hereinafter referred to as the "main body portion 31"). As mentioned above, the present invention is not limited to this embodiment.

[0032] The length of the downstream tube 3 is not particularly limited, but is typically 1,400 mm or more, preferably 1,600 mm or more, and 3,000 mm or less, preferably 1,800 mm or less. More specifically, the downstream tube 3 may be, for example, approximately 1,600 to 1,700 mm long. The outer and inner diameters of the downstream tube 3 are determined taking into consideration the outer diameter of the upstream tube 2, ease of insertion into the body, and ease of insertion of the current-carrying wire 4 and first pusher member 5 (described below). The outer diameter of the downstream tube 3 is typically 1.5 mm or more, preferably 2 mm or more, more preferably 2.3 mm or more, and typically 4 mm or less, preferably 3 mm or less. The inner diameter of the downstream tube 3 is typically 1.0 mm or more, preferably 1.3 mm or more, and typically 3 mm or less, preferably 1.5 mm or less. For example, the outer diameter of the downstream tube 3 can be approximately 2.33 mm (7 Fr).

[0033] The material of the rear tube 3 can be a thermoplastic resin or a thermosetting resin, such as polyethylene (PE), polypropylene (PP), or polyurethane (PU). The material of the rear tube 3 can be selected in relation to the material of the front tube 2. For example, if polyethylene is used for both the front tube 2 and the rear tube 3, the front tube 2 can be made of low-density polyethylene (LDPE) and the rear tube 3 can be made of high-density polyethylene (HDPE), which has excellent rigidity.

[0034] The outer diameter of the front tube 2 is slightly larger than the inner diameter of the second joint end 3a of the rear tube 3. The first joint end 2b of the front tube 2 is forced into and fitted into the second joint end 3a of the rear tube 3, thereby joining the front tube 2 to the rear tube 3 by frictional force. As mentioned above, the present invention is not limited to this embodiment.

[0035] There are no particular limitations on the shape of the joint portion between the first joint end 2b of the front tube 2 and the second joint end 3a of the rear tube 3. For example, as shown in Figure 2, the second joint end 3a of the rear tube 3 may be shaped so that its diameter expands radially outward due to elastic deformation when the first joint end 2b of the front tube 2 is fitted. Also, for example, the inner surface 3c of the second joint end 3a of the rear tube 3 may be shaped so that its diameter gradually increases toward the tip.

[0036] In this embodiment, the distal end 2 a of the front tube 2 and the distal end portion of the second joint end 3 a of the rear tube 3 are rounded to avoid damaging the tissue or to allow smooth penetration through the wall. The distal end portion of the second joint end 3 a is not limited to being rounded.

[0037] [Electrified Wire 4] As shown in Figure 4, an electrically conductive wire 4 is inserted into the front tube 2 and rear tube 3 of the drainage tube 1. The electrically conductive wire 4 is used to penetrate and cauterize the organ wall of the gallbladder 11. The electrically conductive wire 4 has an outer diameter smaller than the inner diameter of the front tube 2. When a high-frequency current is passed through the electrically conductive wire 4, Joule heat is generated at the tip end 4a of the electrically conductive wire 4, causing the wire to form a perforation 10a in the gallbladder 11 (see Figure 8). The base end 4b of the electrically conductive wire 4 is connected to a high-frequency current generator 42 via a high-frequency power cord 41.

[0038] 5 , a first pushing member 5 for separating the front tube 2 from the rear tube 3 is insertably provided inside the rear tube 3 of the drainage tube 1. The first pushing member 5 is used to push the first joint end 2b, which is opposite the tip end 2a that is inserted into the gallbladder 11, out of the second joint end 3a of the rear tube 3. The first pushing member 5 is insertable inside the rear tube 3.

[0039] The first extrusion member 5 is not hollow (see FIG. 13 ). The first extrusion member 5 may be hollow, taking into consideration ease of handling during extrusion, rigidity, toughness, and the like. For example, the first extrusion member 5 may be a tubular or coil-shaped member. In this case, the outer diameter of the first extrusion member 5 is at least larger than the inner diameter of the front tube 2 and smaller than the inner diameter of the rear tube 3. Examples of materials that can be used for the first extrusion member 5 include stainless steel, nickel titanium, and plastic. The outer diameter of the first extrusion member 5 is set to a size sufficient to extrude the front tube 2. The outer diameter of the first extrusion member 5 is typically 1 mm or more, preferably 1.2 mm or more, and typically 2 mm or less, preferably 1.7 mm or less. More specifically, the outer diameter of the first extrusion member 5 is approximately 1.33 mm (4.0 Fr) to 1.5 mm (4.5 Fr), for example. The first pushing member 5 can also be selected based on the ease of sliding of the front tube 2 relative to the rear tube 3 .

[0040] As described above, the first joint end 2b of the front tube 2 is pushed into the second joint end 3a of the rear tube 3 and joined by frictional force. The pushing tip 5a located at the tip of the first pushing member 5 abuts against the first joint end 2b of the front tube 2 within the rear tube 3 and is configured to be able to push further. The first pushing member 5 is configured to be able to apply a pushing force to the first joint end 2b of the front tube 2 that is greater than the frictional force generated between the front tube 2 and the rear tube 3.

[0041] [Operation Unit 6] As shown in FIGS. 1, 6, and 7, the operation unit 6 has a double-tube structure composed of an inner tube 61 and an outer tube 62. The inner tube 61 is inserted inside the outer tube 62 in a manner that allows it to move in the front-to-rear direction. The base end 3b of the rear tube 3 is inserted inside the inner tube 61 and connected thereto. The tip 62a of the outer tube 62 is located at the rear end 100b of the endoscope 100. The operation unit 6 is not located inside the endoscope 100. The rear tube 3 and the front tube 2 are inserted inside the endoscope 100, and by moving the inner tube 61 in the front-to-rear direction relative to the outer tube 62, the rear tube 3 connected to the inner tube 61 moves in the front-to-rear direction together with the front tube 2. When the drainage tube 1 is inserted inside the endoscope 100 and the inner tube 61 is not inserted into the outer tube 62, the front tube 2 does not protrude from the tip 100a of the endoscope 100, as shown in FIG. 6. On the other hand, when the drainage tube 1 is inserted inside the endoscope 100 and the inner tube 61 is inserted into the outer tube 62, at least the front tube 2 protrudes forward from the tip 100a of the endoscope 100, as shown in Figure 7.

[0042] As shown in FIG. 6 , the endoscope 100 is a known flexible endoscope. The endoscope 100 has an insertion section that is inserted into the body from its tip, and is used by inserting a drainage tube 1 into the endoscope 100. The endoscope 100 is a medical device that is inserted directly or indirectly into tissue inside the body (the gallbladder 11 in this embodiment). An imaging section is provided at the tip 100a of the endoscope 100, and is capable of capturing images of the area to be treated. As the endoscope, for example, an endoscope having an optical imaging element such as a CCD or CMOS in the imaging section, or an ultrasound endoscope equipped with an ultrasound element that can scan the back side of an organ wall in addition to such an imaging element, can be used.

[0043] [Method for Discharging Pus Using the Drainage Tube 1] Next, an example of a procedure for draining pus from the gallbladder 11 using the drainage tube 1 will be described in detail with reference to FIGS. 6 to 13.

[0044] First, with the drainage tube 1 retracted, the endoscope 100 is inserted through the nose or mouth, and the tip 100 a of the endoscope 100 is positioned near the gallbladder 11 in the stomach or duodenum 12 .

[0045] Next, as shown in Fig. 6 , the rear tube 3, to which the front tube 2 is joined, is inserted through the endoscope 100. As shown in Fig. 7 , the inner tube 61 of the control unit 6 is moved forward inside the outer tube 62, causing at least the tip 2a of the front tube 2 to protrude forward from the tip 100a of the endoscope 100.

[0046] Next, as shown in Fig. 8 , an electric wire 4 through which a high-frequency current is applied is inserted from the rear of the rear tube 3 of the drainage tube 1, and the tip 4a of the electric wire 4 is cauterized and penetrates the organ walls of the stomach or duodenum 12 and the gallbladder 11. Specifically, as shown in Fig. 9A , the tip 2a of the front tube 2 is positioned near the inner wall 12b of the stomach or duodenum 12. Next, as shown in Fig. 9B , the tip 4a of the electric wire 4 is protruded forward within the drainage tube 1 to penetrate the organ walls 12a, 11a of the stomach or duodenum 12 and the gallbladder 11, respectively, and positioned so as to cross the penetration portions of the stomach or duodenum 12 and the gallbladder 11 through which the front tube 2 has penetrated. Thereafter, as shown in Fig. 9C , the electric wire 4 is withdrawn from the rear end 100b of the endoscope 100 (see Figs. 6 and 7 ).

[0047] Next, as shown in Fig. 10, a washing solution consisting of a diluent such as physiological saline is injected into the gallbladder 11 via the front tube 2 using an injector 7, such as a syringe, from the inner tube 61 of the operating section 6 of the drainage tube 1 to dilute the pus in the gallbladder 11, and the mixture of pus and diluent is then discharged outside the body. After repeating this discharge procedure at least once, the front tube 2, which is disposed across the organ walls 12a, 11a of the stomach or duodenum 12 and the gallbladder 11, is separated from the rear tube 3, as shown in Fig. 11. Depending on the state of the discharged material, such as pus, in the gallbladder 11, it may not be necessary to inject a diluent and discharge the mixture of pus and diluent outside the body.

[0048] Specifically, as shown in Figure 12, a cleaning solution is injected into the gallbladder 11 using an injector 7, thereby diluting the pus in the gallbladder 11. The mixture of the cleaning solution and the pus is discharged to the outside of the body through a drainage tube 1 inserted into the body. Note that the injection of the diluent and the discharge of the mixture to the outside of the body can be carried out one or more times.

[0049] 13A to 13C, once the washing solution injected into the gallbladder 11 has been diluted with pus and the drainage process is complete, the front tube 2 is separated from the rear tube 3, and only the rear tube 3 is removed from the body. Specifically, as shown in FIG. 13A, the first pushing member 5 is inserted into the rear tube 3 from the inner tube 61 of the control unit 6. Inside the rear tube 3, the pushing tip 5a of the first pushing member 5 abuts against the first joint end 2b of the front tube 2, and as shown in FIG. 13B, the first pushing member 5 is pushed further forward. By applying a predetermined pushing force to the first pushing member 5 in this manner, the first joint end 2b of the front tube 2 overcomes the frictional force with the second joint end 3a of the rear tube 3, and the front tube 2 is released from the rear tube 3. The rear tube 3 may also be pulled backward during the operation of pushing the first pushing member 5. This facilitates release. By carrying out these steps, the work of placing the front tube 2 of the drainage tube 1 at a predetermined position inside the body is completed.

[0050] Thereafter, an outlet tube (not shown) is inserted into the body, for example, from the nose, and the bile in the gallbladder 11 is discharged to the outside of the body through the front tube 2 and the outlet tube.

[0051] As described above, the drainage tube 1 according to this embodiment discharges waste fluids such as pus that have accumulated in the gallbladder 11 inside the body to the outside of the gallbladder 11. The drainage tube 1 includes an upstream tube 2 that is inserted into the gallbladder 11, and a downstream tube 3 that is joined to one of the ends of the upstream tube 2 that is opposite the end that is inserted into the gallbladder 11. The upstream tube 2 and the downstream tube 3 are joined by fitting the inner surface 3c of the downstream tube 3 into the outer surface 2c of the upstream tube 2.

[0052] In the drainage tube 1 according to this embodiment, the first joint end 2b of the front tube 2 is joined to the second joint end 3a of the rear tube 3 in a fitted state by frictional force. Therefore, the front tube 2 and the rear tube 3 can be mechanically released from each other, and while employing a simple structure, the front tube 2 can be separated from the rear tube 3 at an appropriate timing and placed at a predetermined position inside the body. In this embodiment, the timing of separation differs from conventional cases in which a dissolvable material is used at the connection between the two tubes, the front tube 2 and the rear tube 3. In other words, in this embodiment, the timing of separation of the front tube 2 and the rear tube 3 can be freely controlled, allowing for optimal and efficient response according to the progress of treatment.

[0053] A first pushing member 5, which is used to separate the front tube 2 from the rear tube 3, can be inserted into the interior of the rear tube 3 of the drainage tube 1 according to this embodiment. The first pushing member 5 can push out one of the ends of the front tube 2 opposite the end that is inserted into the gallbladder 11.

[0054] In this case, the first pushing member 5 can be inserted from behind the rear of the rear tube 3 at any timing after the front tube 2 has been placed at a predetermined position in an organ inside the body. This causes the pushing tip 5a of the first pushing member 5 to abut against the first joint end 2b of the front tube 2 inside the rear tube 3, and the first pushing member 5 is further pushed forward to apply a predetermined pushing force to the first pushing member 5. In this embodiment, this causes the first joint end 2b of the front tube 2 to overcome the frictional force with the second joint end 3a of the rear tube 3, and the front tube 2 can be mechanically detached from the rear tube 3.

[0055] The drainage tube 1 according to this embodiment has an outer diameter smaller than the inner diameter of the front tube 2. An electric wire 4, the tip of which can form a perforation in the gallbladder 11 by passing a high-frequency current through it, can be inserted through the front tube 2 and the rear tube 3.

[0056] In this case, an electric wire 4 is used, and the electric wire 4 is inserted into the rear tube 3 and the front tube 2 of the drainage tube 1, and the tip of the electric wire protruding from the tip of the front tube 2 is used to burn the gallbladder 11 and form a perforation.

[0057] In the drainage tube 1 of this embodiment, the upstream tube 2 can be placed in the tissue inside the body at any timing for one or more tissues selected from the gallbladder, bile duct, abscess, and digestive tract (in this embodiment, the gallbladder 11).

[0058] Furthermore, in the drainage tube 1 according to this embodiment, the rear tube 3 is extended to the outside of the body. In the drainage tube 1, a diluent is injected from outside the body via the rear tube 3 and the front tube 2 into the gallbladder 11 inside the body and mixed with the drained liquid, and then the mixture of the drained liquid and the diluent can be extended to the outside of the body via the front tube 2 and the rear tube 3.

[0059] In this embodiment, before the upstream tube 2 is separated from the downstream tube 3, a diluent is injected from outside the body via the downstream tube 3 and the upstream tube 2 into the gallbladder 11 inside the body and mixed with the effluent, and the mixture of the effluent and diluent is then discharged outside the body via the upstream tube 2 and the downstream tube 3. In this embodiment, the timing of separation of the upstream tube 2 can be set as desired, allowing sufficient dilution using the diluent to be performed depending on the patient's condition.

[0060] In the drainage tube 1 according to this embodiment, the downstream tube 3 can be separated from the upstream tube 2 after the injection of the diluent and the discharge of the mixture to the outside of the body are performed one or more times.

[0061] In this embodiment, before the upstream tube 2 is separated from the downstream tube 3, injection of the diluent and discharge of the mixture to the outside of the body can be performed one or more times depending on the patient's condition.

[0062] According to the drainage tube 1 of this embodiment, the timing of separation of the rear tube and the front tube can be controlled.

[0063] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, modifications, or examples. Additions, omissions, substitutions, and other modifications of the configuration are possible within the scope of the present invention. Furthermore, the present invention is not limited by the above description, but is limited only by the scope of the appended claims.

[0064] In this embodiment, the configuration is such that a first pushing member 5 is provided that is used to separate the upstream tube 2 from the downstream tube 3, but it is also possible to omit this first pushing member 5. As in the above-described embodiment, the first pushing member 5 is provided so that the first joint end 2b, which is one of both ends of the upstream tube 2 and is opposite the tip end 2a that is inserted into the gallbladder 11, can be pushed out and inserted into the downstream tube 3, but this is not limitative. The point is that it is sufficient that the joint between the upstream tube 2 and the downstream tube 3, which are joined by fitting, can be released at any time.

[0065] 14A and 14B show the configuration of a second pushing member 5A according to a modified example, illustrating the state in which the front tube 2 is separated from the rear tube 3. This modified example is an example in which the first pushing member 5 and second pushing member 5A described above are used in combination. The front tube 2 includes the second folded portion 22B (22) shown in FIGS. 3D and 3E described above. A stepped portion 22b having a larger diameter than the outer surface 2c (circumferential surface) of the front tube 2 is formed at the base end 22a of the second folded portion 22B. The second pushing member 5A according to the modified example is provided at the tip of the endoscope 100. The second pushing member 5A is a member formed with a V-shaped groove 5b for engaging a device (not shown) used in the endoscope 10, and is configured to be movable in the axial direction (longitudinal direction) of the front tube 2. The second pushing member 5A is configured to be able to press the V-shaped groove 5b against the outer surface 2c of the front tube 2. In this modified example, as shown in FIG. 14A , the first joint end 2b of the leading tube 2 is pushed forward X1 by the pushing tip 5a of the first pushing member 5 inserted into the rear tube 3. As shown in FIG. 14B , simultaneously with or after the first pushing member 5 pushes the leading tube 2, the V-groove 5b of the second pushing member 5A is pressed against the outer surface 2c of the leading tube 2. At this time, the second pushing member 5A engages with the stepped portion 22b of the second folded portion 22B of the leading tube 2, restricting movement of the leading tube 2 toward the rear X2. The leading tube 2 can then be separated from the rear tube 3 by pulling the rear tube 3 toward the rear X2. While the modified example uses both the first pushing member 5 and the second pushing member 5A, a method using only the second pushing member 5A without using the first pushing member 5 is also possible.

[0066] In addition, an electric wire 4 is provided which has an outer diameter smaller than the inner diameter of the front tube 2 and is capable of forming a perforation in the gallbladder 11 at its tip by passing a high-frequency current through it, and the electric wire 4 is not limited to a configuration in which it can be inserted into the front tube 2 and the rear tube 3.

[0067] In this embodiment, the rear tube 3 is extended to the outside of the body, and the diluent is injected from outside the body via the rear tube 3 and the front tube 2 into the gallbladder 11 (tissue) inside the body and mixed with the effluent, and then the mixture of the effluent and diluent can be extended to the outside of the body via the front tube 2 and the rear tube 3, but the configuration is not limited to this.

[0068] The drainage tube according to the present invention can be applied to a drainage tube that can control the timing of separation of the rear tube and the front tube.

[0069] REFERENCE SIGNS LIST 100 Endoscope 1 Drainage tube 2 Front tube 2a Distal end 2b First joint end 3 Rear tube 3a Second joint end 3b Base end 4 Conducting wire 5 First pushing member (pushing member) 5A Second pushing member (pushing member) 6 Operation unit 11 Gallbladder (tissue) 12 Duodenum 61 Inner tube 62 Outer tube

Claims

1. A drainage tube that discharges drainage fluid such as pus accumulated in tissues inside the body to the outside of the tissues, a front tube that is inserted into the tissue, and a rear tube that is joined to one of the ends of the front tube opposite to the end that is inserted into the tissue, the front tube and the rear tube are joined by fitting the inner surface of the rear tube into the outer surface of the front tube; the front tube and the rear tube have a tip end projecting from the front tube's distal end through which a current-carrying wire can be inserted, the current-carrying wire being provided to form a perforation by passing a high-frequency current through the tissue; The drainage tube is characterized in that at least a portion of the front tube is formed in a curved shape, extends in a straight line when the current-carrying wire is inserted, and returns to its original curved shape when the current-carrying wire is pulled out.

2. The upstream tube has the function of injecting cleaning fluid from outside the body into the tissue inside the body and the function of discharging a mixture of the cleaning fluid and the drainage fluid outside the body, and has openings formed at at least both ends in the longitudinal direction.A drainage tube as described in claim 1.

3. A drainage tube as described in claim 1, wherein the front-stage tube has an axial portion extending in the longitudinal direction, a first folded portion that engages when the front-stage tube is pulled rearward, and a second folded portion that folds in the opposite direction to the first folded portion.

4. A drainage tube separation mechanism that separates the front tube and the rear tube of the drainage tube described in any one of claims 1 to 3, a push-out member for separating the rear tube from the front tube is provided at the tip of an endoscope into which the drainage tube is inserted; the push-out member has a movement restricting portion that restricts rearward movement of the front tube, A drainage tube separation mechanism that separates the front tube from the rear tube by pulling the rear tube backward while the movement of the front tube is restricted by the movement restriction portion.

5. The movement regulating portion is a V-groove-shaped hook portion that hooks onto the outer surface of the front-stage tube, The drainage tube separation mechanism according to claim 4 , wherein rearward movement of the front tube is restricted by hooking the hook portion onto the outer surface.