Instrument for drainage and use thereof

Abstract

Provided is a technique for making it possible to suppress faults in drainage stent placement. This instrument for drainage comprises: a balloon catheter that has an expandable balloon part, a leading end part continuous with the leading end of the balloon part, and a shaft part continuous with the rear end of the balloon part; and a sheath in which a through-hole is formed along the longitudinal direction, and in which the shaft part is inserted into the through-hole. The through-hole is configured to be capable of having a drainage stent inserted therein in a state where the balloon catheter has been removed. The diameter of the through-hole is larger than the outer diameter of the drainage stent.

Description

Drainage devices and their uses

[0001] This application is based on Japanese Patent Application No. 2024-013883, filed February 1, 2024, the contents of which are incorporated herein by reference.

[0002] In the presence of malignant biliary strictures, such as those caused by bile duct cancer, or benign biliary strictures, such as those caused by inflammatory scarring, bile stasis may occur in the peripheral bile duct, potentially resulting in jaundice or cholangitis. Therefore, it is necessary to drain the dilated bile duct peripheral to the stricture. Endoscopic biliary drainage is generally performed via a transpapillary approach. For example, as described in Non-Patent Document 1, endoscopic biliary drainage involves dilating the bile duct stricture using a balloon dilation device, then removing the dilation device and inserting a plastic or metal drainage stent. Furthermore, as described in Non-Patent Document 1, endoscopic ultrasound biliary drainage may also be performed.

[0003] Gastrointestinal Endoscopy, Tokyo Medical Publishing, Vol.33, No.3, 2021, 518-521, 568-572.

[0004] In endoscopic biliary drainage, even if a stricture in the bile duct is dilated using a balloon dilation device, the dilation may not be maintained, making it difficult for the drainage stent to penetrate the stricture. Furthermore, in endoscopic ultrasound biliary drainage, the gallbladder or bile duct is punctured with a needle and then dilated with a balloon, which can lead to bile leakage and cause peritonitis. Such problems can occur not only in the biliary tract but also in the abdominal cavity, such as the pancreatic duct. Therefore, there is a need for technology that can prevent problems during drainage stent placement.

[0005] The present invention can be realized as the following aspects.

[0006] (1) According to one aspect of the present disclosure, there is provided a drainage device. The drainage device of this aspect includes a balloon catheter having an expandable balloon portion, a distal end portion connected to the distal end of the balloon portion, and a shaft portion connected to the proximal end of the balloon portion, and a sheath having a through-hole formed along its longitudinal direction and into which the shaft portion is inserted, the through-hole being configured to allow a drainage stent to be inserted when the balloon catheter is removed, and the diameter of the through-hole being larger than the outer diameter of the drainage stent. With this drainage device, a path can be secured using the sheath after the balloon portion is expanded, thereby preventing problems during drainage stent placement.

[0007] (2) In the drainage instrument described in (1) above, the diameter of the through hole may be 7.3 Fr. or more and 9.0 Fr. or less, and the outer diameter of the sheath may be 8.5 Fr. or more and 10.0 Fr. or less. According to this form of drainage instrument, it is possible to suppress a decrease in insertability of the sheath while suppressing a decrease in insertability of the drainage stent into the through hole.

[0008] (3) In the drainage instrument described in (1) or (2) above, the difference between the diameter of the through-hole and the outer diameter of the shaft portion may be 0.5 Fr. or more and 1.5 Fr. or less. According to this form of drainage instrument, the difference between the diameter of the through-hole and the outer diameter of the shaft portion is 0.5 Fr. or more and 1.5 Fr. or less, which prevents a decrease in the force transmission between the sheath and the balloon catheter, thereby preventing a decrease in the breakthrough force of the balloon catheter.

[0009] (4) In the drainage device according to any one of (1) to (3), the balloon portion in an expanded state may have an outer diameter of 3 mm or more and 6 mm or less. In this drainage device, the outer diameter of the balloon portion in an expanded state is 3 mm or more and 6 mm or less, so that deterioration in operability can be suppressed.

[0010] (5) In the drainage instrument according to any one of (1) to (4), the sheath may include a metal mesh. In this form of the drainage instrument, the metal mesh prevents the sheath from bending or becoming blocked.

[0011] (6) The drainage device according to any one of (1) to (5) above may further include the drainage stent. With this configuration of the drainage device, it is possible to suppress a decrease in convenience.

[0012] (7) In the drainage device described in (6) above, the drainage stent may be made of plastic. With this type of drainage device, the plastic drainage stent can be easily placed.

[0013] (8) In the drainage device described in (6) above, the drainage stent may be made of metal. With this type of drainage device, the metal drainage stent can be easily placed.

[0014] (9) The drainage device according to any one of (1) to (8) above may be a biliary drainage device. This drainage device can suppress problems that may occur when placing a drainage stent in the biliary tract.

[0015] (10) According to another aspect of the present disclosure, there is provided an endoscopic biliary drainage method using the drainage instrument according to any one of (1) to (9), comprising: a first step of inserting the sheath, into which the balloon catheter in an unexpanded state has been inserted, from the duodenal papilla into a bile duct; a second step of expanding the balloon portion after the balloon portion has reached a stricture in the bile duct; a third step of unexpanding the balloon portion while advancing the sheath to the stricture or after the sheath has reached the stricture; a fourth step of removing the balloon catheter from the through-hole; a fifth step of inserting the drainage stent into the through-hole to reach the stricture; and a sixth step of removing the sheath from the bile duct while leaving the drainage stent in a region including the stricture. According to this embodiment of the endoscopic biliary drainage method, the drainage stent can be placed easily, thereby preventing problems that may occur during placement of the drainage stent.

[0016] (11) According to another aspect of the present disclosure, there is provided a method for endoscopic ultrasound biliary drainage using the drainage instrument according to any one of (1) to (9). The method for endoscopic ultrasound biliary drainage includes step A of inserting the sheath, into which the balloon catheter in a non-expanded state is inserted, into the duodenum or stomach, step B of expanding the balloon portion after reaching a perforation formed from the duodenum or stomach to the gallbladder or bile duct, step C of advancing the sheath to reach the perforation while keeping the balloon portion in a non-expanded state, step D of removing the balloon catheter from the through-hole, step E of inserting the drainage stent into the through-hole to reach the perforation, and step F of removing the sheath from the perforation while leaving the drainage stent in a region including the perforation. According to this embodiment of the ultrasonic endoscopic gallbladder drainage method, bile leakage from the perforation can be suppressed, thereby preventing problems with drainage stent placement.

[0017] The present disclosure can be realized in various forms, for example, a biliary drainage kit including a balloon catheter and a sheath, a method for manufacturing a biliary drainage instrument, a method for assisting treatment using a biliary drainage instrument, etc. The present disclosure can also be realized in the form of a drainage kit including a balloon catheter and a sheath, a method for manufacturing a drainage instrument, a method for assisting treatment using a drainage instrument, etc.

[0018] FIG. 1 is an explanatory diagram schematically showing the overall configuration of a biliary drainage instrument. FIG. 2 is an explanatory diagram showing an example of a method of using a biliary drainage instrument. FIG. 3 is a process chart showing an endoscopic biliary drainage method. FIG. 4 is an explanatory diagram showing details of a third step. FIG. 5 is an explanatory diagram showing an endoscopic biliary drainage method of a comparative example. FIG. 6 is an explanatory diagram showing another example of a method of using a biliary drainage instrument. FIG. 7 is a process chart showing an ultrasonic endoscopic biliary drainage method. FIG. 8 is an explanatory diagram showing an ultrasonic endoscopic gallbladder drainage method of a comparative example. FIG. 9 is an explanatory diagram showing another example of a method of using a drainage instrument.

[0019] According to one embodiment of the present disclosure, a drainage instrument 100 is provided. The drainage instrument 100 is used to place a drainage stent in a drainage procedure. Applicable drainage procedures include, but are not limited to, biliary drainage, pancreatic duct drainage, pseudocyst drainage, and intraperitoneal abscess drainage. A biliary drainage instrument 100 will be described below as an example of a preferred embodiment of the drainage instrument 100 of the present disclosure.

[0020] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a biliary drainage device according to one embodiment of the present disclosure. The biliary drainage device 100 of the present disclosure is used to place a drainage stent during biliary drainage. The biliary drainage device 100 includes a balloon catheter 10 and a sheath 20. Note that FIG. 1 illustrates each component diagrammatically, and therefore the dimensions of each component differ from the actual dimensions.

[0021] The balloon catheter 10 has a tubular appearance with a generally circular cross section. The balloon catheter 10 includes a balloon portion 12, a tip portion 14, and a shaft portion 16. The balloon portion 12 is expandable. The balloon portion 12 is expanded by an inflator (not shown) or the like connected to the rear end of the balloon catheter 10. FIG. 1 shows the balloon portion 12 in an expanded state. The outer diameter of the balloon portion 12 in an expanded state is preferably 3 mm to 6 mm, and more preferably 4.0 mm to 6 mm, from the viewpoint of suppressing a decrease in operability. The tip portion 14 is continuous with the distal end of the balloon portion 12. The tip portion 14 is tapered, with the diameter decreasing toward the distal end. The tapered tip portion 14 suppresses a decrease in breakthrough force. The shaft portion 16 is continuous with the rear end of the balloon portion 12. The outer diameter of the shaft portion 16 is preferably 7.0 Fr. or less, and more preferably 6.5 Fr. or less, from the viewpoint of suppressing a decrease in insertability into the through-hole 22. In the present disclosure, 1 mm is equivalent to 3 Fr. (French).

[0022] The sheath 20 has a tubular external shape that is generally circular in cross section. The sheath 20 has a through-hole 22 formed along its longitudinal direction. The shaft portion 16 of the balloon catheter 10 is inserted into the through-hole 22. Therefore, the diameter of the through-hole 22, i.e., the inner diameter of the sheath 20, is larger than the outer diameter of the shaft portion 16. The diameter of the through-hole 22 is also larger than the outer diameter of the balloon portion 12 in an unexpanded state and the outer diameter of the tip portion 14. The through-hole 22 is configured to allow a drainage stent to be inserted into it when the balloon catheter 10 is removed. Therefore, the biliary drainage device 100 of the present disclosure is used together with a drainage stent that can be inserted into the through-hole 22. The diameter of the through-hole 22 is larger than the outer diameter of the drainage stent.

[0023] The difference between the diameter of the through hole 22 and the outer diameter of the shaft portion 16 of the balloon catheter 10 is preferably 0.5 Fr. or more and 1.5 Fr. or less, and more preferably 0.8 Fr. or more and 1.2 Fr. or less, from the viewpoint of preventing a decrease in the force transmission between the sheath 20 and the balloon catheter 10. This configuration prevents an excessive gap from being formed between the through hole 22 and the shaft portion 16, thereby preventing a decrease in the transmission force and, as a result, preventing a decrease in the breakout force of the balloon catheter 10.

[0024] The diameter of the through hole 22 of the sheath 20 is preferably 7.3 Fr. or greater from the viewpoint of preventing a decrease in insertability of the drainage stent into the through hole 22. A diameter of 7.3 Fr. or greater is also preferable from the viewpoint of easily removing the balloon catheter 10 in an unexpanded state. Furthermore, the diameter of the through hole 22 is preferably 9.0 Fr. or less from the viewpoint of ensuring the wall thickness of the sheath 20 while preventing the outer diameter from becoming excessively large. The diameter of the through hole 22 is preferably 7.3 Fr. or greater but not greater than 9.0 Fr., more preferably 7.3 Fr. or greater but not greater than 8.8 Fr., and even more preferably 7.5 Fr. or greater but not greater than 8.5 Fr. The outer diameter of the sheath 20 is preferably 10.0 Fr. or less from the viewpoint of preventing a decrease in insertability of the sheath 20. Furthermore, the outer diameter of the sheath 20 is preferably 8.5 Fr. or greater from the viewpoint of ensuring the diameter of the through hole 22. The outer diameter of the sheath 20 is preferably 8.5 Fr. or more and 10.0 Fr. or less, and more preferably 8.5 Fr. or more and 9.5 Fr. or less. Therefore, from the viewpoint of suppressing a decrease in the insertability of the sheath 20 while suppressing a decrease in the insertability of the drainage stent into the through-hole 22, it is preferable that the diameter of the through-hole 22 is 7.3 Fr. or more and 9.0 Fr. or less, and the outer diameter of the sheath 20 is 8.5 Fr. or more and 10.0 Fr. or less.

[0025] In this embodiment, the sheath 20 includes a metal mesh. The inclusion of the metal mesh can prevent kinking of the sheath 20. That is, bending and occlusion of the sheath 20 can be prevented. The sheath 20 is preferably coated on the inner surface of the metal mesh, and more preferably coated on both the inner and outer surfaces. Coating the inner surface of the metal mesh can prevent a decrease in the insertability of the drainage stent inserted into the through-hole 22. Coating the outer surface of the metal mesh can prevent a decrease in the insertability of the sheath 20. The material of the metal mesh is not particularly limited, but examples include stainless steel, titanium, nickel, tungsten, etc., and may also be an alloy of various metals. The material of the coating is not particularly limited, but examples include silicon and PTFE (polytetrafluoroethylene).

[0026] The drainage stent used with the biliary drainage device 100 of the present disclosure may be made of plastic or metal. In general, plastic drainage stents are easy to remove, while metal drainage stents have excellent expandability. The biliary drainage device 100 of the present disclosure allows for easy placement of plastic or metal drainage stents.

[0027] FIG. 2 is an explanatory diagram showing an example of a method for using the biliary drainage instrument 100. FIG. 3 is a process diagram showing an endoscopic biliary drainage method. FIG. 2 chronologically illustrates the placement of a drainage stent in a stricture 210 of a bile duct 200 during transpapillary biliary drainage, an endoscopic biliary drainage method. FIG. 2 shows, as an example, an example in which the stricture 210 is present in an intrahepatic bile duct. It is assumed that the biliary drainage instrument 100 is inserted and removed along a guidewire (not shown). For this reason, it is assumed that the endoscopic biliary drainage method is performed with a guidewire (not shown) already placed in the bile duct 200.

[0028] First, the sheath 20 with the unexpanded balloon catheter 10 inserted therein is inserted through the duodenal papilla 220 into the bile duct 200 (step P110). In the following description, step P110 is also referred to as the first step. After the balloon portion 12 reaches the stricture 210 of the bile duct 200, it is expanded (step P120). In the following description, step P120 is also referred to as the second step. In the second step, the balloon portion 12 is expanded by an inflator (not shown) or the like connected to the rear end of the shaft portion 16. FIG. 2 shows the balloon portion 12 expanded in the second step, spanning both the front and rear of the stricture 210.

[0029] As shown in Fig. 3, the balloon portion 12 is brought into a non-expanded state while or after the sheath 20 is advanced to reach the stricture 210 (step P130). In the following description, step P130 is also referred to as the third step. Fig. 2 shows the state in which the balloon portion 12 is brought into a non-expanded state while the sheath 20 is advanced to reach the stricture 210 in the third step.

[0030] 4 is an explanatory diagram showing the details of the third step. In FIG. 4, the forward movement direction of the sheath 20 is indicated by an arrow pointing to the left side of the page, and the position of the stricture 210 is indicated by a triangle. By simultaneously deflating the balloon portion 12 and advancing the sheath 20, the stricture 210 can be broken through and the sheath 20 can be inserted into the area to be drained.

[0031] In the third step, from the viewpoint of preventing excessive advancement of the balloon catheter 10, it is preferable to advance the sheath 20 to reach the stricture 210 while placing the balloon portion 12 in an unexpanded state. If there is space within the bile duct 200 for further advancement of the balloon catheter 10, the sheath 20 may be advanced to reach the stricture 210 and then the balloon portion 12 may be placed in an unexpanded state. In the third step, the pressure in the balloon portion 12 may be gradually released by an inflator (not shown) or the like connected to the rear end of the shaft portion 16, or the pressure in the balloon portion 12 may be released all at once. However, it is preferable to gradually place the balloon portion 12 in an unexpanded state by dissipating pressure. Upon completion of the third step, the distal end of the sheath 20 breaks through the stricture 210, and the sheath 20 maintains the dilation of the stricture 210.

[0032] As shown in Figure 3, the balloon catheter 10 is removed from the through-hole 22 (step P140). In the following description, step P140 is also referred to as the fourth step. In the fourth step, the unexpanded balloon catheter 10 is removed. Upon completion of the fourth step, the sheath 20 alone bridges the front and rear of the stricture 210.

[0033] The drainage stent 30 is inserted into the through-hole 22 to reach the stricture 210 (step P150). In the following description, step P150 will also be referred to as the fifth step. The sheath 20 is removed from the bile duct 200 while the drainage stent 30 is placed in the area including the stricture 210 (step P160). In the following description, step P160 will also be referred to as the sixth step. This completes the placement of the drainage stent 30.

[0034] FIG. 5 is an explanatory diagram showing an endoscopic biliary drainage method according to a comparative example. FIG. 5 chronologically illustrates the placement of a drainage stent 430 at a stricture 210 in a bile duct 200 during transpapillary biliary drainage, an endoscopic biliary drainage technique. Unlike the present application, the instrument 400 used in this comparative example does not include a sheath 20. In this comparative example, a balloon catheter 410 inserted into the bile duct 200 from the duodenal papilla 220 reaches the stricture 210 and is then expanded. After the balloon catheter 410 is removed, a drainage stent 430 is inserted into the bile duct 200 to penetrate the stricture 210. However, according to the comparative example, even though the stricture 210 is expanded by the balloon catheter 410, the expansion may not be maintained after the balloon catheter 410 is removed, resulting in restenosis. This situation is particularly likely to occur when the biliary stricture is severe, regardless of whether it is benign or malignant. If restenosis occurs, it becomes difficult to pass the drainage stent 430 through the stricture 210. Furthermore, even if the dilation of the stricture 210 is maintained after the balloon catheter 410 is removed, a step or the like formed at the tip of the drainage stent 430 may make it difficult to insert the drainage stent 430. This situation is particularly likely to occur when the drainage stent 430 to be placed is made of plastic due to its structure. Since a final solution cannot be achieved unless the drainage stent 430 is placed in the peripheral area to be drained, if the above-mentioned problem occurs, additional treatment using a different approach is required, which may result in a worsening of the patient's condition.

[0035] In contrast, with the biliary drainage instrument 100 of the present disclosure, a path can be secured by the sheath 20 after the balloon portion 12 is expanded, making it possible to easily place the drainage stent 30. As a result, problems such as the inability to break through the stricture 210 can be prevented when placing the drainage stent 30 during endoscopic biliary drainage.

[0036] FIG. 6 is an explanatory diagram showing another example of a method for using a biliary drainage instrument. FIG. 7 is a process diagram showing a method for endoscopic ultrasound biliary drainage. In FIG. 6, endoscopic ultrasound gallbladder drainage (EUS-GBD) is shown in chronological order from the top to the bottom of the page as an example of endoscopic ultrasound (EUS) biliary drainage. More specifically, the diagram schematically shows the process of perforating the duodenum 300 and the gallbladder 310 to place a drainage stent 30. It is assumed that the biliary drainage instrument 100 is inserted and removed along a guidewire (not shown). Therefore, in the ultrasonic endoscopic biliary drainage method, it is assumed that the procedure is performed in a state in which a perforation 330 is formed by puncturing the duodenum 300 into the gallbladder 310 through observation using an ultrasonic endoscope (not shown), and a guide wire (not shown) is placed in the area including the perforation 330.

[0037] First, the sheath 20 with the unexpanded balloon catheter 10 inserted therein is inserted into the duodenum 300 (step P210). In the following description, step P210 will also be referred to as step A. After the balloon portion 12 reaches the perforation 330, which has been drilled from the duodenum 300 to the gallbladder 310, it is expanded (step P220). In the following description, step P220 will also be referred to as step B. In step B, the balloon portion 12 is expanded by an inflator (not shown) or the like connected to the rear end of the shaft portion 16. FIG. 6 shows the balloon portion 12 expanded in step B across both the front and rear of the perforation 330.

[0038] As shown in FIG. 7 , the sheath 20 is advanced to reach the perforation 330 while the balloon portion 12 is unexpanded (step P230). In the following description, step P230 is also referred to as step C. According to step C, even if the relative positions of the duodenum 300 and the gallbladder 310 change, the sheath 20 can be advanced into the gallbladder 310 by deflating the balloon portion 12 and advancing the sheath 20 at the same time. In step C, the pressure in the balloon portion 12 may be gradually released or suddenly released by an inflator (not shown) connected to the rear end of the shaft 16. However, it is preferable to gradually release the pressure in the balloon portion 12 to the unexpanded state by dissipating pressure. Completion of step C establishes communication between the duodenum 300 and the gallbladder 310 via the sheath 20 through the perforation 330.

[0039] The balloon catheter 10 is removed from the through-hole 22 (step P240). In the following description, step P240 will also be referred to as step D. A drainage stent 30 is inserted into the through-hole 22 to reach the perforation 330 (step P250). In the following description, step P250 will also be referred to as step E. The drainage stent 30 used in step E is preferably made of metal from the viewpoint of excellent expandability. Note that FIG. 6 shows a shaft 90 for delivering the drainage stent 30. While the drainage stent 30 is placed in the region including the perforation 330, the sheath 20 is removed from the perforation 330 (step P260). In the following description, step P260 will also be referred to as step F. This completes placement of the drainage stent 30, forming a fistula between the duodenum 300 and the gallbladder 310.

[0040] FIG. 8 is an explanatory diagram showing a comparative example of an endoscopic ultrasound gallbladder drainage method. In FIG. 8, the endoscopic ultrasound gallbladder drainage is shown in chronological order from top to bottom of the page as endoscopic biliary drainage. Unlike the present application, the instrument 500 used in this comparative example does not include a sheath 20. In this comparative example, the gallbladder 310 is visualized by ultrasound through the duodenum 300 using an EUS 320, and then a needle 510 is inserted from the duodenum 300 to the gallbladder 310. After that, a guidewire 520 is placed, and the puncture path at the puncture site 340 is expanded with a balloon catheter 530. The balloon catheter 530 is then removed, and a drainage stent is inserted. However, this comparative example lacks safety because bile leakage may cause peritonitis.

[0041] In contrast, with the biliary drainage device 100 of the present disclosure, a path can be secured by the sheath 20 after the balloon portion 12 is expanded, making it possible to easily place the drainage stent 30. As a result, when placing the drainage stent 30 during endoscopic ultrasound biliary drainage, bile leakage from the perforation 330 can be suppressed. This can prevent problems from occurring during placement of the drainage stent 30, thereby preventing a decrease in safety. Furthermore, by using a metal drainage stent 30, bile leakage from the perforation 330 can be further suppressed, thereby further preventing a decrease in safety.

[0042] The configuration of the biliary drainage instrument 100 in the above embodiment is merely an example and can be modified in various ways. For example, the biliary drainage instrument 100 may further include a drainage stent 30. This configuration can prevent a decrease in convenience. The drainage stent 30 included in the biliary drainage instrument 100 may be made of plastic. This configuration allows the plastic drainage stent 30 to be easily placed. The drainage stent 30 included in the biliary drainage instrument 100 may be made of metal. This configuration allows the metal drainage stent 30 to be easily placed. A biliary drainage instrument 100 including a metal drainage stent 30 is suitable for use in forming a fistula during endoscopic ultrasound biliary drainage. Furthermore, in the above embodiment, the biliary drainage instrument 100 has been described as being applied to transpapillary biliary drainage and endoscopic ultrasound gallbladder drainage, but the present disclosure is not limited thereto. For example, the endoscopic ultrasound biliary drainage instrument 100 may be used not only for EUS-GBD but also for EUS-HGS (hepaticogastrostomy), which forms a fistula between the stomach and the bile duct, or for EUS-CDS (choledochoduodenostomy), which forms a fistula between the duodenum and the bile duct. In other words, a method for endoscopic ultrasound biliary drainage may generally include a step A of inserting the sheath 20, into which the unexpanded balloon catheter 10 is inserted, into the duodenum 300 or the stomach, and a step B of expanding the balloon portion 12 after the balloon portion 12 reaches the perforation 330 formed from the duodenum 300 or the stomach to the gallbladder 310 or the bile duct 200.

[0043] 9 is an explanatory diagram showing another example of a method of using the drainage instrument 100. Fig. 9 shows the drainage instrument 100 of the present disclosure being used for pancreatic duct drainage. Pancreatic duct drainage can be performed in a similar manner to the biliary duct drainage described above. Note that drainage instruments 100 used in areas other than the biliary tract can also employ a configuration similar to that of the biliary tract drainage instrument 100, which is an example of a preferred embodiment described above.

[0044] FIG. 9 shows endoscopic pancreatic stenting (EPS) using the drainage device 100 of the present disclosure in chronological order, from (1) to (6). Generally, EPS is performed primarily to treat pancreatic duct strictures due to chronic pancreatitis. As shown in FIG. 9(1), a stricture 620 in the pancreatic duct 600 is confirmed through the duodenal papilla 220 by contrast imaging using a side-viewing endoscope 610. After placing a guidewire 630, a sheath 20 with an unexpanded balloon catheter 10 inserted therein is inserted from the duodenal papilla 220 into the pancreatic duct 600. Then, as shown in FIG. 9(2), the balloon portion 12 is expanded across the stricture 620 and both its anterior and posterior regions. As shown in FIG. 9(3), the balloon portion 12 is deflated while the sheath 20 is advanced to reach the stricture 620. As shown in Figure 9 (4), the sheath 20 maintains the dilation of the stricture 210 and bridges the area in front of and behind the stricture 620, and the undilated balloon catheter 10 is then removed. As shown in Figure 9 (5), a drainage stent 30 is inserted into the through-hole 22 of the sheath 20 and placed in the area anterior to the stricture 620 where drainage is required. As shown in Figure 9 (6), with the drainage stent 30 placed beyond the stricture 620, the sheath 20 is removed from the pancreatic duct 600. This completes the EPS procedure.

[0045] This method includes a first step of inserting a sheath 20 having a non-expanded balloon catheter 10 inserted therein through the duodenal papilla 220 into the pancreatic duct 600; a second step of expanding the balloon portion 12 after the balloon portion 12 reaches a narrowed portion 620 in the pancreatic duct 600; a third step of advancing the sheath 20 to the narrowed portion 620 or after the sheath 20 reaches the narrowed portion 620 and then changing the balloon portion 12 to the non-expanded state; a fourth step of removing the balloon catheter 10 from the through-hole 22; a fifth step of inserting a drainage stent 30 into the through-hole 22 to reach the narrowed portion 620; and a sixth step of removing the sheath 20 from the pancreatic duct 600 while leaving the drainage stent 30 in the area including the narrowed portion 620.

[0046] Furthermore, in the above embodiment, EUS-GBD has been described as an example of endoscopic ultrasound drainage, but the present disclosure is not limited thereto. The drainage instrument 100 of the present disclosure may be used, for example, for endoscopic ultrasound-guided cyst drainage (EUS-CD), abscess drainage, etc. That is, the drainage instrument 100 of the present disclosure may be applied to a pancreatic pseudocyst or abscess in a broad sense, such as an infection of fluid retention (pancreatic juice, bile, or intestinal juice) after abdominal surgery. Such drainage can also be performed in a manner similar to the above-described EUS-GBD, by inserting a needle into the target pseudocyst or abscess from the stomach or duodenum.

[0047] This method includes step A of inserting a sheath 20 with an unexpanded balloon catheter 10 inserted therein into the duodenum 300 or the stomach; step B' of expanding the balloon portion 12 after it reaches a perforation 330 that has perforated the duodenum 300 or the stomach into a pseudocyst or abscess; step C of advancing the sheath 20 to reach the perforation 330 while putting the balloon portion 12 into an unexpanded state; step D of removing the balloon catheter 10 from the through-hole 22; step E of inserting a drainage stent 30 into the through-hole 22 so that it reaches the perforation 330; and step F of removing the sheath 20 from the perforation 330 while leaving the drainage stent 30 in place in the area including the perforation 330.

[0048] The present invention is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and examples corresponding to the technical features in each aspect described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate.

[0049] 10...balloon catheter, 12...balloon portion, 14...tip portion, 16...shaft portion, 20...sheath, 22...through hole, 30...drainage stent, 90...shaft, 100...drainage instrument (biliary drainage instrument), 200...bile duct, 210...stricture portion, 220...duodenal papilla, 300...duodenum, 310...gallbladder, 320...EUS, 330...perforation portion, 340...puncture site, 400...instrument, 410...balloon catheter, 430...drainage stent, 500...instrument, 510...needle, 520...guidewire, 530...balloon catheter, 600...pancreatic duct, 610...side endoscope, 620...stricture portion, 630...guidewire

Claims

1. A drainage device comprising: a balloon catheter having an expandable balloon portion, a tip portion connected to the tip of the balloon portion, and a shaft portion connected to the rear end of the balloon portion; and a sheath having a through hole formed along the longitudinal direction and having the shaft portion inserted into the through hole, wherein the through hole is configured to allow a drainage stent to be inserted into it when the balloon catheter is removed, and the diameter of the through hole is larger than the outer diameter of the drainage stent.

2. A drainage instrument according to claim 1, wherein the diameter of the through-hole is between 7.3 Fr. and 9.0 Fr., and the outer diameter of the sheath is between 8.5 Fr. and 10.0 Fr.

3. A drainage instrument according to claim 1 or 2, wherein the difference between the diameter of the through-hole and the outer diameter of the shaft portion is 0.5 Fr. or more and 1.5 Fr. or less.

4. A drainage device according to claim 1 or 2, wherein the balloon portion in an expanded state has an outer diameter of 3 mm or more and 6 mm or less.

5. A drainage device according to claim 1 or 2, wherein the sheath includes a metal mesh.

6. The drainage device according to claim 1 or 2, further comprising the drainage stent.

7. The drainage device according to claim 6, wherein the drainage stent is made of plastic.

8. The drainage device according to claim 6, wherein the drainage stent is made of metal.

9. The drainage instrument according to claim 1 or 2, which is a biliary drainage instrument.

10. A method for endoscopic biliary drainage using the drainage instrument according to claim 1 or 2, comprising: a first step of inserting the sheath, into which the balloon catheter in an unexpanded state has been inserted, from the duodenal papilla into the bile duct; a second step of expanding the balloon portion after the balloon portion has reached a stricture in the bile duct; a third step of moving the sheath forward to reach the stricture, and then bringing the balloon portion into an unexpanded state while advancing the sheath and reaching the stricture; a fourth step of removing the balloon catheter from the through-hole; a fifth step of inserting the drainage stent into the through-hole to reach the stricture; and a sixth step of removing the sheath from the bile duct while leaving the drainage stent in place in the area including the stricture.

11. A method for endoscopic ultrasonic biliary drainage using the drainage instrument according to claim 1 or 2, comprising: step A of inserting the sheath, into which the balloon catheter in a non-expanded state has been inserted, into the duodenum or stomach; step B of expanding the balloon portion after it has reached a perforation that has perforated from the duodenum or stomach to the gallbladder or bile duct; step C of advancing the sheath to reach the perforation while keeping the balloon portion in a non-expanded state; step D of removing the balloon catheter from the through-hole; step E of inserting the drainage stent into the through-hole so that it reaches the perforation; and step F of removing the sheath from the perforation while leaving the drainage stent in place in an area including the perforation.

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