Anti-reflux ureteral stent

Abstract

The present invention provides an anti-reflux ureteral stent. [Solution] One-way drainage is achieved by installing flap-like structures on the side walls of the bladder-end stent, and these flap-like structures are enclosed together with the stent's tubular wall in cross section to form the stent lumen, with the outer surface of the flap-like structures being larger than the inner surface, so that when the external pressure of the flap-like structures is greater than the internal pressure of the flap-like structures, the flap-like structures will adhere to the tubular wall, which will support the flap-like structures and close the lumen. The present invention uses flap-like structures to achieve one-way drainage of ureteral stents and effectively prevent backflow.

Description

[Technical Field]

[0001] The present invention relates to the technical field of medical devices, and in particular to anti-reflux ureteral stents. [Background technology]

[0002] The ureter is a tubular organ connecting the kidney and the bladder, transporting urine from the kidney to the bladder. Ureteral stents are support structures placed within the ureter. They are primarily tubular, but there are also various variations, such as lattice and T-shaped structures. Ureteral stents have retention structures at both ends of the renal pelvis and bladder. These retention structures are typically configured to curl the tubular structure. Specialized retention structures, such as balloon, trumpet, umbrella, coil, and barb shapes, are also available. The retention structures are crucial for preventing displacement of the stent tube and ensuring the ureteral stent's functionality.

[0003] Postoperative placement of a ureteral stent tube is a common treatment for endoluminal kidney and ureteral surgery. Millions of ureteral stents are placed in the human body every year, with placement times ranging from several days to several months. However, many patients experience varying degrees of discomfort after surgery, which affects their quality of life and ability to work, primarily urinary irritation and pain. Current research suggests that a significant cause of this discomfort is urinary reflux due to increased bladder pressure.

[0004] There are three main approaches to reducing vesicopelvic reflux: designing various check valve structures within the lumen of a ureteral stent (e.g., Patent Document 1); installing a check valve at the end of a ureteral stent (e.g., Patent Document 2); and placing the tubular structure of a ureteral stent inside the ureter outside the bladder wall, thereby utilizing the body's own anti-reflux mechanism at the vesicoureteral junction. It is difficult to implement a check valve within the lumen of a thin ureteral stent (less than 2 mm) (e.g., Patent Document 1). If the stent is placed for a long time, urine components may settle in the check valve, rendering the check valve ineffective. Furthermore, the check valve may obstruct the advancement of a guidewire, making ureteral stent placement difficult, and the passage of the guidewire may affect the structure and function of the check valve. While restricting the stent to the outside of the bladder wall of the ureter utilizes the body's own anti-reflux mechanism, the stent's support function may be incomplete, leading to poor urine drainage from the kidneys and potentially causing complications such as lower back pain and fever. Furthermore, it is difficult to maintain the correct position of the ureteral stent, and the stent tube may move upward, resulting in inaccurate drainage. Adding an additional check valve to the end of the ureteral stent (e.g., Patent Document 2) increases the length of the stent, increasing its volume and increasing the irritation symptoms of the stent tube, and making the stent tube more likely to move as urine is discharged during urination, making it difficult to use widely.

[0005] In summary, the ureteral stents currently widely used in clinical practice have reflux problems, which can easily cause discomfort to patients. However, the small size of the ureteral stents makes it difficult to install an anti-reflux structure, and the anti-reflux structure of the human body makes the support function of the ureteral stent incomplete, making it difficult to solve the reflux problem of ureteral stents. Currently, there is no satisfactory solution that can achieve significant anti-reflux effects while maintaining the function of the stent. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] China Utility Model Publication No. 206403899 [Patent Document 2] China Utility Model Publication No. 204563249 Summary of the Invention [Problem to be solved by the invention]

[0007] Based on this, the object of the present invention is to provide an anti-reflux ureteral stent, which achieves its anti-reflux function mainly by the flap-like structure on the side wall of the stent tube, and this solution does not change the shape of the stent tube, does not cause additional irritation to the bladder, does not affect the ability of the lumen in the side wall of the stent tube to pass a guide wire, does not interfere with the drainage ability of the stent tube, and can be easily implemented to solve the above-mentioned shortcomings in the prior art. [Means for solving the problem]

[0008] The present invention provides the following technical solutions: A pipeline body; a first end and a second end respectively disposed at both ends of the conduit body; The first end is positioned within the kidney. The and a first holding structure, the first holding structure being disposed at one end of the conduit body, the first end being disposed at an end of the first holding structure remote from the conduit body, and an opening being provided at the first end; The second end is connected to a second end and a catheter positioned within the bladder. The and a second holding structure, wherein the second holding structure is disposed at an end of the conduit body remote from the first holding structure, and the second end is disposed at an end of the second holding structure remote from the conduit body; the second end and the portion of the stent body located inside the bladder have no openings for liquid flow other than the flap-like structure, and a puncture hole or incision through which a guide wire can pass is formed only at the second end, and the puncture hole or incision is closed in a natural state; The second holding structure and the pipe body within 2 cm of the second holding structure 、1 one or more flap-like structures are provided, the flap-like structures being located on the sides of the pipe wall and not on the second end; The flap-like structure is enclosed in a cross section together with the tubular wall of the stent to form the lumen of the stent, and the outer surface of the flap-like structure is larger than the inner surface of the flap-like structure. When the external pressure of the flap-like structure is larger than the internal pressure of the flap-like structure, the flap-like structure is in close contact with the tubular wall, and the tubular wall supports the flap-like structure to close the lumen. When the external pressure of the flap-like structure is smaller than the internal pressure of the flap-like structure, the flap-like structure is open. Hand pipe Achieve cavity opening.

[0009] Furthermore, the second retaining structure is a curled structure, and the flap-shaped structure is placed inside the curled structure to maintain the integrity of the outer urinary wall and thus the longitudinal strength of the stent tube. In actual use, the ureteral stent must be mounted on a guidewire and pushed forward to the appropriate position using a pusher tube also mounted on the guidewire. If the longitudinal strength of the stent tube is reduced due to the modification, the stent tube cannot be placed using conventional methods. Experiments have shown that if the flap-shaped structure is placed outside the curled structure, the stent tube will wrinkle when being pushed into the body along the guidewire, causing the lumen to deform and wrap around the guidewire, increasing friction and making it difficult to continue pushing the stent tube. By placing the flap-shaped structure inside the curled structure, the longitudinal strength reduction can be avoided and the stent can be ensured to slide smoothly along the guidewire.

[0010] Furthermore, the flap-like structure is provided on the second retention structure so that its distance from the second end is one-fourth the length of the second retention structure, and this portion is less affected by bladder contraction, so that when the bladder contracts, the flap-like structure tends to move together with the second end, further reducing deformation of the flap-like structure due to bladder contraction and reducing the impact of deformation on the anti-reflux capability. Experiments have shown that flap-like structures that are farther from the second end and closer to the main body of the conduit often cannot adhere to the pipe wall when pressed, causing water to leak through the gap between the pipe wall and the flap-like structure, reducing the anti-reflux capability.

[0011] Additionally, the flap-like structure narrows toward the second end.

[0012] Furthermore, the free end of the flap-like structure may be oriented toward a first end to facilitate placement from the kidney to the bladder, or toward a second end to facilitate placement from the bladder to the kidney.

[0013] Furthermore, a recessed groove is provided on the outer wall of the flap-like structure.

[0014] Furthermore, the conduit body and the flap-like structure are made of different materials.

[0015] Additionally, one or more side holes are provided in the first end and the sidewall of the conduit body. [Effects of the Invention]

[0016] Compared with the prior art, the present invention has the following advantageous effects. The flap-like structure of the present invention can be realized by adding a simple cutting process to the existing stent manufacturing process, which basically does not increase manufacturing costs and is highly feasible. Furthermore, the anti-reflux function can be achieved without changing the stent shape or increasing side effects. Using the stent of the present invention does not require the surgeon to change their operating method, which does not incur additional learning costs or risks during surgery. In other words, the application of the present invention achieves the anti-reflux effect without increasing costs, causing side effects, or changing operating habits. A first end and a second end are provided at both ends of the duct body, the first end including a first retaining structure, and the second end including a second retaining structure. In actual use, the first end is located in the renal pelvis, and the second retaining structure and a portion of the duct body approximately 2 cm proximal to the second retaining structure are located in the bladder, with the flap-like structure provided on the stent within the bladder. When the external pressure of the flap-like structure is less than the internal pressure, i.e., when the external pressure of the bladder portion of the stent is less than the internal pressure, the internal pressure pushes the flap-like structure open, allowing the fluid inside to flow out smoothly, achieving smooth drainage from the kidney to the bladder. When the external pressure of the flap-like structure is greater than the internal pressure, i.e., when the external pressure of the stent is greater than the internal pressure, the flap-like structure adheres to the stent's lumen wall, and the stent's lumen wall supports the flap-like structure. Because there is no opening for fluid flow at the second end, the flap-like structure adheres to the lumen wall, isolating the lumen from the outside, preventing external fluid from entering the stent and preventing urine from refluxing into the kidney. In an experiment, when the above-mentioned anti-reflux stent and a standard ureteral stent were placed at the same height in the same saline bottle, the anti-reflux stent completely eliminated reflux compared to the standard ureteral stent. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a structural schematic diagram of an anti-reflux ureteral stent in an embodiment of the present invention. [Figure 2] FIG. 2 is a structural schematic diagram of a second retention structure of an anti-reflux ureteral stent in an embodiment of the present invention. [Figure 3] FIG. 1 is a first cross-sectional view of a flap-like structure of an anti-reflux ureteral stent in accordance with an embodiment of the present invention. [Figure 4] FIG. 10 is a second cross-sectional view of a flap-like structure of an anti-reflux ureteral stent in accordance with an embodiment of the present invention. [Figure 5] 2 is a cross-sectional view of a second end of an anti-reflux ureteral stent according to an embodiment of the present invention.

[0018] The following specific embodiments further illustrate the present invention with reference to the above drawings. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0019] To facilitate an understanding of the present invention, the present invention will now be described more fully hereinafter with reference to the associated drawings, in which several embodiments of the present invention are shown. However, this invention may be embodied in many different forms and is not limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0020] It should be noted that when an element is said to be "fixedly mounted" to another element, it may be directly connected to the other element, or there may be intervening elements. When an element is considered to be "connected" to another element, it may be directly connected to the other element, or there may also be intervening elements. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for descriptive purposes only.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting of the invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] 1 to 5 show an anti-reflux ureteral stent according to an embodiment of the present invention, which includes a ductal body 10, a first end 20 and a second end 30. As shown in FIG.

[0023] The aforementioned The first end 20 is placed in the kidney. The aforementioned The second end 30 is placed in the bladder. The aforementioned First end 20 and The aforementioned The second ends 30 are each The aforementioned Installed at both ends of the pipeline body 10, The aforementioned The first end 20 includes a first end 21 and a first retention structure 22 for placement within the kidney; The aforementioned The first holding structure 22 The aforementioned It is installed at one end of the pipeline body 10, The aforementioned The first end 21 The aforementioned First holding structure 22 The aforementioned It is installed at an end far from the main pipe body 10, The aforementioned The second end 30 is connected to the second end 31 and the catheter 32. The and two retaining structures 32; The aforementioned The second holding structure 32 The aforementioned Pipe body 10 The aforementioned located at an end remote from the first retaining structure 22; The aforementioned The second end 31 The aforementioned The second holding structure 32 The aforementioned It is installed at an end far from the main pipe body 10, The aforementioned The second end 31 has no opening for fluid flow, only a puncture hole for the passage of a guide wire; The aforementioned a second retaining structure 32 and The aforementioned Within 2 cm of the second retention structure 32 The aforementionedThe main body 10 has 、1 one or more flap-like structures 33 are provided, The aforementioned The flap-like structure 33 is located on the side of the pipe wall, and The aforementioned It is not installed at the second end 31. The aforementioned The flap-like structure 33 is surrounded by the stent lumen together with the stent wall in cross section, The aforementioned The outer surface 333 of the flap-like structure 33 The aforementioned larger than the inner surface 332 of the flap-like structure 33; The aforementioned The external pressure of the flap-like structure 33 The aforementioned If the internal pressure of the flap-like structure 33 is greater than The aforementioned The flap-like structure 33 The aforementioned Adheres to the pipe wall, The aforementioned The pipe wall The aforementioned Supporting the flap-like structure 33 The aforementioned Achieving luminal closure, The aforementioned The external pressure of the flap-like structure 33 The aforementioned If the internal pressure of the flap-like structure 33 is less than The aforementioned The flap-like structure 33 opens to provide an open lumen.

[0024] As can be understood, at this time, The aforementioned The duct body 10 is disposed in the ureter, The aforementioned a first end 20 and The aforementioned The second end 30 is located in the kidney and the bladder, respectively, and after urine is produced, it is transported to the kidney by the peristaltic movement of the smooth muscle of the renal pelvis. The aforementioned It flows to the second end 30 . The aforementioned If the pressure of urine in the second retention structure 32 is higher than the pressure of urine in the bladder, the pressure in the bladder will be The aforementioned The pressure inside the flap-like structure 33 is smaller than that inside the flap-like structure 33. The aforementioned The flap-like structure 33 opens, opening the lumen and allowing urine to escape. The aforementioned The bladder is then filled with urine. The aforementioned If the pressure in the flap-like structure 33 is greater than The aforementioned The flap-like structure 33 The aforementioned second end 30 or The aforementioned It adheres closely to the pipe wall structure of the pipe body, The aforementioned second end 30 or The aforementionedThe pipe wall structure of the main pipe is The aforementioned Supporting the flap-like structure 33; The aforementioned The flap-like structure 33 cannot be deformed into the lumen, and the lumen is closed, so urine The aforementioned cannot flow into the second holding structure 32, The aforementioned The second end 31 has no opening for fluid flow, only a puncture hole for the guide wire to pass through, and urine The aforementioned No fluid can flow into the second retaining structure 32, thereby providing an anti-reflux function and improving the patient's comfort in use.

[0025] In this embodiment, the flap-like structure 33 is enclosed in cross section together with the wall structure of the second end 30 or the duct body 10 to form the lumen of the stent, and the outer surface 333 of the flap-like structure 33 is larger than the inner surface 332 of the lumen, maintaining sufficient structural strength to maintain the lumen structure. When the external pressure of the flap-like structure 33 is greater than the internal pressure of the flap-like structure 33, the flap-like structure 33 adheres to the wall structure of the second end 30 or the duct body 10, and the wall structure of the second end 30 or the duct body 10 supports the flap-like structure 33, preventing the flap-like structure 33 from deforming into the lumen, resulting in a closed lumen. When the external pressure of the flap-like structure 33 is less than the internal pressure of the flap-like structure 33, the flap-like structure 33 opens, opening the lumen and achieving a one-way drainage effect.

[0026] The flap-like structures 33 can be formed by cutting the tubular structure of an existing stent tube, or by removing a portion of the tubular wall of the stent tube and adding the flap-like structures 33. The pressure required to open the flap-like structures 33 can be adjusted by adjusting the thickness and size of the base of the flap-like structures 33. The drainage ability of the flap-like structures 33 can be adjusted by adjusting the length and size of the flap-like structures 33. The incision 334 may have various shapes, such as an L-shape, a cambered shape, or an arc shape.

[0027] In a specific implementation, when a patient urinates, the pressure inside the bladder rises, and the flap-like structure 33 is pressed against the outer wall of the second retaining structure 32, preventing urine from flowing back from the duct into the kidney. During the process of drainage from the kidney, the staff cuts an opening at the first end 21, which allows urine to enter the first retaining structure 22, pass through the duct body 10, and enter the second retaining structure 32. At this time, because there is drained urine in the duct body 10, the pressure inside the duct body 10 is greater than the external pressure, i.e., the internal pressure of the flap-like structure 33 is greater than the external pressure, so that the internal pressure pushes open the flap-like structure 33, allowing urine to smoothly enter the bladder.

[0028] As can be seen, the first end 20, i.e., the side wall of the first retention structure 22 and the side wall of the conduit body 10, are both provided with one or more side holes 300 to facilitate drainage of urine.

[0029] The first holding structure 22 is placed in the kidney, and at this time, a portion of one end of the conduit main body 10 connected to it is also placed in the kidney, and the second holding structure 32 is placed in the bladder, and a portion of the conduit main body 10 connected to the second holding structure 32 is also placed in the bladder, so the flap-like structure 33 may be placed at the end of the conduit main body 10 close to the second holding structure 32, or may be placed in the second holding structure 32.

[0030] The conduit body 10, first end portion 21, first retaining structure 22, second end portion 31, second retaining structure 32, and flap-like structure 33 are integrally molded. If the second retaining structure 32 is considered to be a circular ring, the flap-like structure 33 is located within the inner ring of the second retaining structure, or within 2 cm of the second retaining structure within the conduit body 10.

[0031] Furthermore, the above The second holding structure 32 is a curled structure, The aforementioned The flap-like structure 33 is The aforementioned Installed inside the curled structure RThis maintains the integrity of the outer tube wall and thus the longitudinal strength of the stent tube. This prevents wrinkles from forming in the stent tube as it is pushed along the guidewire, deforming the lumen and making it difficult to push the stent tube into the body.

[0032] In addition, the second holding structure 32 is provided with a plurality of flap-like structures 33. In this embodiment, two flap-like structures 33 are provided on the outer wall of the second holding structure 32. The flap-like structures 33 are provided on the second holding structure 32 so that the distance from the second end 31 is one-fourth the length of the second holding structure 32. do.

[0033] In order to prevent backflow of liquid from the drainage side holes, no drainage side holes are provided within 2 cm of the connection point between the conduit body 10 and the second retaining structure 32 and at the second end 30.

[0034] in particular, The aforementioned The second end 31 has a puncture hole or incision 334 that is used only to pass the guide wire 40 when placing the ureteral stent, and it closes naturally in the absence of the guide wire 40 to prevent backflow of fluid through the opening. Note that because the second end 31 is attached to one end of the second retention structure 32 and the flap-like structure 33 is attached to the second retention structure 32, the flap-like structure 33 can serve as a drain when opened, and therefore the puncture hole in the second end 31 does not need to allow fluid to pass through.

[0035] in particular, The aforementioned First end 20 and The aforementioned The side wall of the pipe body 10 、1 At least one side hole 300 is provided.

[0036] in particular, The aforementioned Flap-like structure 33 The aforementionedThe end closer to the second end 31 gradually narrows, and as can be seen, the flap-like structure 33 gradually narrows at one end so as to better fit with the outer wall of the second retaining structure 32, as the flap-like structure 33 is cut out above the outer wall of the second retaining structure 32 in the form of a side cut.

[0037] Preferably , The aforementioned The flap-like structure 33 is The aforementioned The width of the second retaining structure 32 is gradually narrowed from the end connected to the second retaining structure 32, and the width is in the range of 1 / 6 to 1 / 5 of the circumference of the outer wall of the conduit of the second retaining structure, and the length is about 5 times the width. The aforementioned The free ends of the flap-like structures 33 have less mass and are able to complete their drainage function more easily.

[0038] In some alternative embodiments, the width of the flap-like structures 33 may be the same, achieving the same anti-reflux effect.

[0039] In some alternative embodiments, the flap-like structure 33 The aforementioned The end closest to the second end 31 gradually narrows, then widens and finally narrows again, making it more convenient when the flap-like structure 33 is pushed open.

[0040] As can be understood, in a specific implementation, since the flap-like structure 33 is close to the second end 31, the second end 31 is free, and this part is less affected by bladder contraction, and when the bladder contracts, the flap-like structure 33 has a stronger tendency to move together with the second end 31, which further reduces the deformation of the flap-like structure 33 due to bladder contraction and reduces the impact of the deformation on the anti-reflux ability.

[0041] moreover , The aforementioned Flap-like structure 33 and The aforementionedThe flap-shaped structure 33 is adhered to the outer wall of the second retention structure 32 by a water-soluble polymer material. When the anti-reflux ureteral stent is placed in a patient's body, the flap-shaped structure 33 is adhered to the outer wall of the second retention structure 32 by the water-soluble polymer material, facilitating placement in the body. The water-soluble polymer material dissolves in urine produced by the human body, allowing the flap-shaped structure 33 to open and close, thereby preventing reflux. In this embodiment, the water-soluble polymer material is fibrin. Furthermore, the orientation of the flap-shaped structure can be adjusted to accommodate placement from the bladder to the kidney and from the kidney to the bladder, respectively, or to facilitate placement in the body without the use of an adhesive material.

[0042] In addition, The aforementioned A lateral groove 331 is provided on the outer wall of the flap-like structure 33, and further, a plurality of lateral grooves 331 are provided on the outer wall of the flap-like structure 33. In this embodiment, one lateral groove 331 is provided on the inner wall of the flap-like structure 33. By providing such a configuration, the pressure difference required to open the flap-like structure 33 can be effectively reduced, and the flap-like structure 33 can better perform its drainage function.

[0043] Preferably , The aforementioned Pipe body 10 and The aforementioned The flap-like structures 33 are made of different materials, which effectively reduces the pressure difference required to open and close the flap-like structures.

[0044] In some alternative embodiments, The aforementioned Pipe body 10, The aforementioned First end 20 and The aforementioned The second end 30 is made of polyurethane or silicone. The conduit body 10, the first end 21, the first holding structure 22, the second end 31, the second holding structure 32, and the flap-like structure 33 are all made of polyurethane or silicone.

[0045] In addition, The aforementioned Pipe body 10 and The aforementionedThe flap-like structure 33 is made of a different material; in this embodiment, the conduit body 10 is made of polyurethane, and the flap-like structure 33 is made of silicone.

[0046] The effectiveness of the solution of the present invention was confirmed by the following experiment.

[0047] Materials: The ureteral stent manufacturer provided a ureteral stent blank made of the same material (polyurethane) as the commercial stent tube. This blank had no side holes, was closed at one end, and open at the other, with an outer diameter of 6 mm. A test anti-reflux stent was fabricated by curling a structure onto the closed end of the blank, incising the ductal wall, and forming a 6 mm x 1.5 mm flap with its base facing the open end of the stent tube. The closed end of the same ureteral stent blank was left open to simulate a standard ureteral stent.

[0048] Drainage capacity test: The open ends of the test anti-reflux stent tube and the simulated standard ureteral stent were placed in a 500ml infusion bag, and the other ends were placed in 100ml measuring cups. The drainage capacity of the two types of stents was measured at pressures of 20cm and 40cm water column. At a pressure of 20cm water column, the drainage volume of the anti-reflux stent was 90% of that of the standard ureteral stent, and at a pressure of 40cm water column, the drainage volume of the anti-reflux stent was 120% of that of the standard ureteral stent.

[0049] Backflow prevention test: The flap-shaped end of the test anti-reflux stent tube and the open end of a simulated standard ureteral stent were placed in a 500ml infusion bag, which was then connected to a pressure gauge. A 100ml measuring cup was placed at each end, and the drainage capacity of the two stents was measured at 30cm and 60cm water columns, respectively. The anti-reflux stent with flaps on the stent body and the inner curled structure achieved complete reflux prevention, while the drainage rate of the stent with flaps on the sides and outer sides of the curled structure was 10-30% of that of a standard stent.

[0050] Anti-reflux experiment simulating bladder contraction: The flap-like end of the test anti-reflux stent tube and the open end of a simulated conventional ureteral stent were placed in a 500ml infusion bag, and the other ends were each placed in a 100ml measuring cup. The infusion bag was pressed with a pressure of 60cm of water to deform the ureteral stent, simulating the final state of bladder emptying. Results: The test anti-reflux stent with the flap-like structure positioned closest to the end of the stent demonstrated the strongest stability. The closer the flap-like structure was to the stent body, the more susceptible it was to pressure from the bladder wall, resulting in various degrees of reflux.

[0051] Stent tube pushing experiment: Test anti-reflux stents with different flap positions and numbers were prepared. The closed ends of these stent tubes were perforated with a 1.0 mm square needle to facilitate guidewire passage. A 0.88 mm guidewire was passed through the perforation and extended through the entire stent. A pusher tube was attached to the guidewire and pressed against the perforation end of the stent to propel the stent forward. This simulated the process of pushing a stent into the body during surgery. Results: When the flap structures were located inside the curled section, they had the least effect on the longitudinal strength of the stent tube, allowing it to slide smoothly along the guidewire when pushed with the pusher tube. When the flap structures were located in other positions, the stent tube deformed when pushed longitudinally, increasing friction when gripping the guidewire and making it difficult to slide.

[0052] In summary, the anti-reflux ureteral stent in the above embodiment of the present invention has a first end 20 and a second end 30 disposed at either end of a duct body 10, the first end 20 including a first retaining structure 22, and the second end 30 including a second retaining structure 32, the second retaining structure 32 being provided with a flap-like structure 33. When the external pressure of the duct body 10 is greater than the internal pressure, the flap-like structure 33 will adhere to the outer wall of the second retaining structure 32 to prevent external fluid from entering the second retaining structure 32; when the external pressure of the duct body 10 is less than the internal pressure, the internal pressure will push open the flap-like structure 33, allowing the internal fluid to flow out smoothly, thereby realizing one-way drainage of the ureteral stent and preventing reflux.

[0053] In the description herein, references to terms such as "one embodiment," "some embodiments," "examples," "particular examples," or "some examples" mean that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In the description herein, exemplary references to the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0054] The above examples merely illustrate some embodiments of the present invention, and although the descriptions are specific and detailed, they should not be understood as limiting the scope of the claims of the present invention. It should be noted that a person skilled in the art can make some modifications and improvements without departing from the concept of the present invention, and all of these are within the scope of protection of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined based on the scope of the attached claims. [Industrial Applicability]

[0055] The present invention can be used as an anti-reflux ureteral stent. [Explanation of symbols]

[0056] 10...Conduit body 20...First end 21...First end 22...First retention structure 30...Second end 300...Side hole 31...Second end 32...Second retention structure 33...Flap-like structure 331...Lateral groove 332...Inner surface 333...Outer surface 334...Incision portion 40...Guidewire

Claims

1. 1. An anti-reflux ureteral stent comprising: A pipeline body; a first end and a second end respectively disposed at opposite ends of the conduit body; the first distal end includes a first end and a first retention structure for placement within the kidney, the first retention structure being placed at one end of the conduit body, the first end being placed at an end of the first retention structure remote from the conduit body, and an opening being provided at the first end; the second end includes a second end portion and a second holding structure for placement in the bladder, the second holding structure being placed at an end of the duct body remote from the first holding structure, the second end portion being placed at an end of the second holding structure remote from the duct body, the second holding structure and the duct body within 2 cm of the second holding structure both having one or more flap-like structures, the flap-like structures being placed on a side of the duct wall and not at the second end portion; The flap-shaped structures are enclosed together with the tubular wall of the stent in cross section to form the lumen of the stent, the outer surface of the flap-shaped structures is larger than the inner surface of the flap-shaped structures, and when the external pressure of the flap-shaped structures is greater than the internal pressure of the flap-shaped structures, the flap-shaped structures are in close contact with the tubular wall, and the tubular wall supports the flap-shaped structures to close the lumen, and when the external pressure of the flap-shaped structures is smaller than the internal pressure of the flap-shaped structures, the flap-shaped structures are open to open the lumen.

2. 2. The anti-reflux ureteral stent according to claim 1, wherein the first retention structure and the second retention structure are both curled structures, and the flap-shaped structure is located inside the second retention structure.

3. 3. The anti-reflux ureteral stent of claim 2, wherein the flap-like structure is provided on the second retention structure such that the distance from the second end is one-fourth the length of the second retention structure.

4. The anti-reflux ureteral stent of claim 1, wherein the end of the flap-like structure near the second end is gradually narrowed.

5. The anti-reflux ureteral stent according to claim 1, wherein the flap-like structure and the outer wall of the second retaining structure are bonded together by a water-soluble polymer material.

6. The anti-reflux ureteral stent according to claim 1, characterized in that the outer wall of the flap-shaped structure is provided with a groove.

7. The anti-reflux ureteral stent according to claim 1, wherein the duct body and the flap-like structure are made of different materials.

8. 2. The anti-reflux ureteral stent according to claim 1, wherein the first end and the side wall of the duct body are both provided with one or more side holes.

9. The anti-reflux ureteral stent according to claim 6, wherein the grooves are transverse grooves.

Images