Ureteral stent and manufacturing method thereof
By designing a ureteral stent with a trumpet-shaped renal pelvic end and a fish tail-shaped bladder end, combining biocompatible composite materials and self-cleaning function, the complex and complications of traditional fixation methods are solved, achieving safer and more effective urine drainage.
Patent Information
- Application Number
- CN202510268712.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-07
- Publication Date
- 2025-06-24
AI Technical Summary
The fixation of traditional ureteral stents is complex, which increases the difficulty of surgery and can cause complications such as bladder damage, infection, and urine reflux.
A ureteral stent is designed, with the end of the renal pelvis adopting a trumpet-shaped opening and the end of the bladder adopting a fish tail-shaped opening. The body of the stent is made of biocompatible composite material, and a nano-scale rough layer, nano-titanium dioxide coating and drug sustained-release coating are built on the surface. A fixing frame and anti-reflux sheet are installed inside to prevent urine reflux.
The design reduces irritation to the renal pelvis and bladder mucosa, reduces the risk of infection, avoids urine reflux, and improves the safety and effectiveness of the stent through biocompatible materials and self-cleaning functions.
Smart Images
Figure CN120189618A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of medical devices, and particularly to a ureteral stent and a manufacturing method thereof. Background Art
[0002] A ureteral stent is a medical device used to treat ureteral diseases and plays a key role in the treatment of urinary system diseases. Currently, traditional ureteral stents on the market generally have a curved section at each end and a slender straight tube section in the middle. One curved section is placed in the patient's renal pelvis, and the other curved section is placed in the patient's bladder, which can effectively guide the urine in the patient's renal pelvis to the bladder. In addition to draining urine, the ureteral stent also has the functions of dilating the ureter and preventing ureteral stenosis and adhesion.
[0003] Traditional ureteral stents often require the assistance of complex fixing devices, such as setting expandable elements in the bladder or using external sutures for fixation. These fixation methods not only increase the complexity and time of surgical operations but may also cause a series of complications. For example, the expandable element may damage the bladder mucosa, resulting in problems such as bladder bleeding and inflammation; external sutures may cause infections, and during the patient's activities, the fixing device may fail, leading to stent displacement and affecting the treatment effect. Summary of the Invention
[0004] In order to improve the situation that the fixation methods used in traditional ureteral stents increase the surgical difficulty and may also cause complications, this application provides a ureteral stent and a manufacturing method thereof.
[0005] On the one hand, this application provides a ureteral stent, adopting the following technical solution: A ureteral stent includes a stent body, which is hollow inside and in the shape of a slender tube, and the stent body is made of a biocompatible composite material; a renal pelvis end, which is arranged at one end of the stent body and is connected to the stent body. The end of the renal pelvis end is provided with a renal pelvis end opening in a flared shape; a bladder end, which is arranged at the end of the stent body far from the renal pelvis end and is connected to the stent body. The end of the bladder end is provided with a bladder end opening in a fish-tail shape.
[0006] Optionally, the biocompatible composite material is one or a mixture of more of poly(lactic-co-glycolic acid), poly(lactic-co-caprolactone), glycolide, polycaprolactone, gelatin, polyurethane, silicone, polytetrafluoroethylene, and expanded polytetrafluoroethylene.
[0007] Optionally, the outer walls of the stent body, the renal pelvis end, and the bladder end are all etched with a nanoscale rough layer.
[0008] Optionally, a titanium dioxide nanotube coating is uniformly distributed outside the nano-scale rough layer on the stent body, the renal pelvis end and the bladder end.
[0009] Optionally, a drug sustained-release coating is coated outside the titanium dioxide nanotube coating on the stent body, the renal pelvis end and the bladder end.
[0010] Optionally, through holes are uniformly spaced on the tube wall of the stent body, and the through holes communicate the inner and outer spaces of the stent body.
[0011] Optionally, a fixing frame is arranged in the hollow interior of the stent body. The fixing frame is arranged parallel to the stent body. The fixing frame divides the inner space of the stent body into two independent and symmetric drainage channels. The two drainage channels are connected at both the head and the tail. Two anti-reflux sheets are fixed at both the head and the tail of the fixing frame. The two anti-reflux sheets at the same end are symmetrically distributed relative to the fixing frame and correspond to the drainage channels one by one. The anti-reflux sheets are made of an elastic material. In the normal state, along the direction from the renal pelvis end to the bladder end, the anti-reflux sheets gradually bend and incline away from the fixing frame. After being pressed, the anti-reflux sheets can bend themselves to conduct or block their corresponding drainage channels.
[0012] Optionally, drainage strips are circumferentially spaced at the edge position of the anti-reflux sheet away from the fixing frame. The drainage strips are all located in the drainage channels and are all arranged parallel to the fixing frame. The head and tail ends of the drainage strips are simultaneously connected to the two anti-reflux sheets in the same drainage channel. The two anti-reflux sheets in the same drainage channel act synchronously through the drainage strips.
[0013] On the other hand, the present application provides a manufacturing method of a ureteral stent for manufacturing the ureteral stent as described above, including the following steps: S1: First, a biocompatible composite material and titanium dioxide are mixed in a high-speed mixer according to a preset ratio. The mixing temperature is 80-100 °C and the time is 10-20 min to uniformly disperse the materials. Then, the mixed materials are dried in a vacuum drying oven. The drying temperature is 60-80 °C and the time is 4-8 hours to remove moisture and volatile impurities. S2: The dried materials are extruded into a slender tube by a precision extruder. The temperature of the extruder is 200-240 °C, the screw speed is 15-25 revolutions per minute, and the traction speed is 0.8-1.2 meters per minute. During the extrusion process, the corresponding shapes of the renal pelvis end opening and the bladder end opening are formed through the corresponding die. Finally, a nano-scale rough structure is constructed on the outer surfaces of the stent body, the renal pelvis end and the bladder end through a plasma etching process. S3: The whole ureteral stent is placed in a reaction kettle containing a titanium dioxide precursor solution, and titanium dioxide is uniformly deposited on the inner and outer surfaces of the whole ureteral stent by a chemical deposition method. Then, the whole ureteral stent is annealed. S4: Dissolve potassium sodium hydrogen citrate and biodegradable polycaprolactone in an organic solvent to prepare a solution with a drug concentration of 10%-30% (weight ratio). Immerse the entire ureteral stent into the solution using the dip coating method, slowly lift it at a speed of 5-10 cm / min, and then dry it in a vacuum drying oven at a drying temperature of 40-60°C to form a drug sustained-release coating on the entire surface of the ureteral stent.
[0014] In summary, this application includes at least one of the following beneficial effects: 1. By designing the opening at the renal pelvis end as a flared opening and the opening at the bladder end as a fish-tail shape. The renal pelvis end is the flared renal pelvis end opening. This shape can closely fit the anatomical structure of the renal pelvis, collect urine in the renal pelvis to the greatest extent, reduce urine residue in the renal pelvis, help maintain a relatively low pressure in the renal pelvis, and at the same time reduce the risk of damage to the renal pelvis mucosa. The bladder end is the fish-tail shaped bladder end opening. Its unique fish-tail shape enables the stent to conform to the urine flow direction in the bladder and maintain a relatively stable position without additional fixation devices, effectively reducing irritation to the bladder mucosa. 2. The ureteral stent is made of a new type of biocompatible nanocomposite material, making the ureteral stent have good biocompatibility and degradability. It can be gradually decomposed into lactic acid and glycolic acid in the body and finally be metabolized and excreted by the human body, reducing the potential risks of long-term indwelling of the stent in the body. The nano-scale rough structure constructed on the outer surface of the ureteral stent has superhydrophobic properties. When urine contacts the stent surface, water droplets will form and quickly slide off, and part of the attached dirt can be carried away during the sliding process, enabling the ureteral stent to have a good self-cleaning function. Nano-titanium dioxide is evenly distributed on the surface of the ureteral stent. Under weak visible light or ultraviolet light irradiation in the body, nano-titanium dioxide generates photo-generated carriers, and then forms reactive oxygen species such as strongly oxidizing hydroxyl radicals and superoxide anion radicals. These reactive oxygen species can decompose organic pollutants such as bacteria and proteins attached to the stent surface, playing a self-cleaning role, effectively preventing bacterial growth and biofilm formation, and reducing the risk of infection. The drug sustained-release coating coated on the outer surface of the ureteral stent can be slowly released during the stent indwelling period, continuously inhibiting bacterial growth and preventing stone formation. 3. By arranging a fixing frame and an anti-reflux sheet inside the stent body, in the normal state, along the direction from the renal pelvis end to the bladder end, the anti-reflux sheet gradually bends and inclines away from the fixing frame. In the normal state, urine flows from the renal pelvis end to the bladder end, and the anti-reflux sheet bends towards the fixing frame under the impact of urine. At this time, the anti-reflux sheet opens the opening of the drainage channel, and urine normally flows through the drainage channel; when urine reflux occurs, the anti-reflux sheet bends away from the fixing frame under the push of urine and internal pressure. During the bending deformation process of the anti-reflux sheet, the drainage channel is gradually closed until it is completely closed finally, thus avoiding the occurrence of urine reflux. Brief Description of the Drawings
[0015] Figure 1 FIG. is a schematic structural diagram showing the overall ureteral stent in Embodiment 1 of the present application; Figure 2 FIG. is a schematic structural diagram showing the shape of the renal pelvis end opening in Embodiment 1 of the present application; Figure 3 FIG. is a schematic structural diagram showing the shape of the bladder end opening in Embodiment 1 of the present application; Figure 4 FIG. is a schematic diagram showing the coating structure of the ureteral stent in Embodiment 1 of the present application; Figure 5 FIG. is a schematic cross-sectional view showing the conducting state of the drainage channel in Embodiment 1 of the present application; Figure 6 FIG. is a schematic cross-sectional view showing the closed state of the drainage channel in Embodiment 1 of the present application; Figure 7 FIG. is Figure 5 a schematic cross-sectional view at A - A.
[0016] Description of the reference numerals: 1, stent body; 11, fixing frame; 12, drainage channel; 13, anti-reflux sheet; 131, free end; 132, fixed end; 14, drainage strip; 2, renal pelvis end; 21, renal pelvis end opening; 3, bladder end; 31, bladder end opening; 4, through hole; 5, nano-scale rough layer; 6, nano-titanium dioxide coating; 7, drug sustained-release coating. Detailed Description of the Embodiment
[0017] The following further elaborates on the present application in conjunction with the attached Figures 1-7 drawings. Embodiment 1
[0018] Embodiment 1 of the present application discloses a ureteral stent. Refer to Figures 1 to 4, the ureteral stent successively includes a stent body 1, a renal pelvis end 2 and a bladder end 3. The inside of the stent body 1 is hollow, and the stent body 1 has an elongated tubular appearance. The renal pelvis end 2 and the bladder end 3 are respectively distributed at both ends of the stent body 1, and both the renal pelvis end 2 and the bladder end 3 are communicated with the stent body 1. The stent body 1, the renal pelvis end 2 and the bladder end 3 can all be made of a novel biocompatible nanocomposite material, and the novel biocompatible nanocomposite material can be composed of one or a mixture of more of poly(lactic-co-glycolic acid), poly(lactic-co-caprolactone), glycolide, polycaprolactone, gelatin, polyurethane, silica gel, polytetrafluoroethylene and expanded polytetrafluoroethylene.
[0019] In Example 1 of the present application, it is preferably composed of a composite of poly(lactic-co-glycolic acid) (PLGA) and nano-titanium dioxide. Poly(lactic-co-glycolic acid) (PLGA) has good biocompatibility and degradability, and can be gradually decomposed into lactic acid and glycolic acid in the body and finally excreted by human metabolism, reducing the potential risk of long-term indwelling of the stent in the body. Nano-TiO2 endows the material with antibacterial and photocatalytic self-cleaning properties, and can generate strongly oxidizing substances under light conditions, effectively decomposing organic pollutants such as bacteria and proteins attached to the surface of the stent.
[0020] The whole stent body 1 is in an elongated tubular shape, with a length of 20 - 30 cm, and can be specifically customized according to individual patient differences to meet the length requirements of the ureters of different patients, ensuring that the stent can be accurately placed in the ureter, extending from the renal pelvis to the bladder, effectively supporting the ureter and promoting urine drainage. The wall thickness of the stent body 1 is 0.2 - 0.4 mm. This thickness can not only ensure that the stent has sufficient support strength to prevent the ureter from collapsing, but also will not cause excessive compression on the ureteral wall, ensuring the normal physiological function and blood circulation of the ureter.
[0021] The end of the renal pelvis end 2 is provided with a renal pelvis end opening 21 in a flared shape, and the diameter of the renal pelvis end opening 21 is 3 - 5 mm. This shape can closely fit the anatomical structure of the renal pelvis, collect the urine in the renal pelvis to the greatest extent, reduce the residue of urine in the renal pelvis, help maintain a relatively low pressure in the renal pelvis, and at the same time reduce the risk of damage to the renal pelvis mucosa. The end of the bladder end 3 is provided with a bladder end opening 31 in a fish-tail shape. The fish-tail branches are 2 - 3 cm long and 0.3 - 0.5 cm wide. Its unique shape enables the stent to conform to the flow direction of urine in the bladder and can maintain a relatively stable position without additional fixing devices, effectively reducing the irritation to the bladder mucosa.
[0022] On the tube walls of the stent main body 1, through holes 4 are evenly distributed. The through holes 4 communicate the inner and outer spaces of the stent main body 1. The diameter of the through holes 4 is 0.1 - 0.3 mm. These through holes 4 contribute to the penetration and drainage of urine inside and outside the stent, reduce the retention of urine in the stent, and lower the possibility of infection and stone formation. In Embodiment 1 of the present application, the stent main body 1, the renal pelvis end 2, and the bladder end 3 are all provided with through holes 4.
[0023] Furthermore, on the outer walls of the stent main body 1, the renal pelvis end 2, and the bladder end 3, a nano-scale rough layer 5 is etched through a micro-nano processing technology (plasma etching technology), forming a micro-nano protrusion array similar to the surface of a lotus leaf on the surface of the ureteral stent. The height of these micro-nano protrusions is between 50 - 200 nm, and the spacing is about 100 - 300 nm, so that the surface of the stent has superhydrophobic properties, and the water contact angle can reach more than 150°. When urine contacts the surface of the stent, water droplets will form and slide off quickly, and part of the attached dirt, such as bacteria and protein fragments, can be carried away during the sliding process.
[0024] On the nano-scale rough layer 5 of the stent main body 1, the renal pelvis end 2, and the bladder end 3, a nano-titanium dioxide coating 6 is evenly distributed. After depositing nano-TiO2 on the surface of the stent by chemical deposition method, it is annealed to make it crystallized and enhance the bonding force with the material of the stent main body 1. Under weak visible light or ultraviolet light irradiation in the body, nano-TiO2 generates photo-generated carriers, and then forms highly oxidative hydroxyl radicals (·OH) and superoxide anion radicals (O2 - ·) and other reactive oxygen species. These reactive oxygen species can decompose organic pollutants such as bacteria and proteins attached to the surface of the stent, play a self-cleaning role, effectively prevent the growth of bacteria and the formation of biofilms, and reduce the risk of infection.
[0025] Furthermore, on the outer coating of the nano-titanium dioxide coating 6 of the stent main body 1, the renal pelvis end 2, and the bladder end 3, a drug sustained-release coating 7 is coated. The drug is selected as a drug with dual functions of broad-spectrum antibacterial and anti-stone, such as potassium sodium hydrogen citrate. Potassium sodium hydrogen citrate and biodegradable polycaprolactone (PCL) are dissolved in an organic solvent (such as dichloromethane) to prepare a solution with a drug concentration of 10% - 30% (weight ratio). The stent is immersed in the solution by dip coating method, so that the drug is evenly attached to the surface of the stent to form a coating with a thickness of about 0.03 - 0.08 mm. The drug in the coating can be slowly released during the stent indwelling period, continuously inhibit the growth of bacteria and prevent the formation of stones, and as the stent material gradually degrades, the drug release rate will be adjusted accordingly to ensure the effective concentration of the drug in the body.
[0026] Furthermore, referring to Figures 5 to 7, a fixing frame 11 is fixedly installed inside the hollow interior of the stent body 1. The fixing frame 11 is arranged parallel to the stent body 1, and the fixing frame 11 divides the interior space of the stent body 1 into two independent and symmetrical drainage channels 12. The two drainage channels 12 are communicated at both the head and tail ends. The urine flowing in from the renal pelvis end 2 is divided into two streams under the separation of the fixing frame 11, and respectively flows through the two drainage channels 12 to the bladder end 3, and finally converges and flows out at the bladder end 3. The fixing frame 11 can increase the number of cavity walls for drainage, thereby improving the drainage efficiency.
[0027] Two anti-reflux sheets 13 are fixedly installed at both the head and tail ends of the fixing frame 11. The two anti-reflux sheets 13 at the same end are symmetrically distributed relative to the fixing frame 11 and correspond to the drainage channels 12 one by one. The anti-reflux sheet 13 has an overall semi-circular cross-sectional appearance, so that the anti-reflux sheet 13 can be adapted to the tubular stent body 1. The anti-reflux sheet 13 includes a free end 131 and a fixed end 132. The straight segment of the anti-reflux sheet 13 is the fixed end 132, and the arc segment is the free end 131. The fixed end 132 of the anti-reflux sheet 13 is fixedly connected to the fixing frame 11.
[0028] The anti-reflux sheet 13 is made of an elastic material. In Embodiment 1 of the present application, the anti-reflux sheet 13 can be made of a composite material of TiO2 + PDMS (polydimethylsiloxane), which can take into account both elasticity and self-cleaning properties. In the normal state, along the direction from the renal pelvis end 2 to the bladder end 3, the anti-reflux sheet 13 gradually bends and inclines away from the fixing frame 11. The urine flowing from the renal pelvis end 2 to the bladder end 3 impacts the anti-reflux sheet 13, and the free end 131 of the anti-reflux sheet 13 is pressed and bends towards the direction close to the fixing frame 11, so that the free end 131 is close to the fixing frame 11. At this time, the anti-reflux sheet 13 conducts the respective corresponding drainage channels 12, so that the urine can flow smoothly through the drainage channels 12. When urine reflux occurs, that is, flowing from the bladder end 3 to the renal pelvis end 2, the free end 131 of the anti-reflux sheet 13 bends away from the fixing frame 11 under the push of the urine and the internal pressure of the body. At this time, the anti-reflux sheet 13 gradually closes the drainage channel 12 during the bending deformation process until the drainage channel 12 is completely closed finally, thereby avoiding the occurrence of urine reflux. The anti-reflux sheets 13 at both the head and tail ends of the fixing frame 11 can form two seals for the urine, further avoiding urine reflux.
[0029] Furthermore, drainage strips 14 are circumferentially and fixedly arranged at the edge positions of the free ends 131 of the anti-reflux sheets 13. All the drainage strips 14 are located in their respective corresponding drainage channels 12, and all the drainage strips 14 are arranged parallel to the fixing frame 11. The head and tail ends of the drainage strips 14 are simultaneously connected to two anti-reflux sheets 13 located in the same drainage channel 12. In the same drainage channel 12, when one of the anti-reflux sheets 13 moves, the other anti-reflux sheet 13 can be driven to move synchronously through the drainage strip 14, so that the two anti-reflux sheets 13 located in the same drainage channel 12 can be opened or closed synchronously. At the same time, the drainage strip 14 can further increase the wall body for effective drainage, promote the full drainage of hydronephrosis, further improve the drainage efficiency, and promote the excretion of stone residues after lithotripsy for kidney stones. When the anti-reflux sheet 13 is impacted by urine, it will deform itself. During the deformation process of the anti-reflux sheet 13, all the drainage strips 14 will be driven to reciprocally peristalsis along the direction of urine flow, which can provide a continuous dilation effect, prevent adhesion formation, and greatly improve the drainage efficiency.
[0030] The implementation principle of the ureteral stent in Embodiment 1 of the present application is as follows: The end of the renal pelvis end 2 has a flared opening appearance, which can closely fit the anatomical structure of the renal pelvis, collect the urine in the renal pelvis to the greatest extent, and reduce the residue of urine in the renal pelvis. The bladder end 3 is a fish-tail structure, enabling the stent to conform to the direction of urine flow in the bladder and maintaining a relatively stable position without additional fixing devices. The surface of the ureteral stent is successively provided with a nano-scale rough layer 5, a nano-titanium dioxide coating 6, and a drug sustained-release coating 7, which can endow the ureteral stent with good self-cleaning function and drug sustained-release effect, maintain the effectiveness and safety of the stent for a long time, reduce the risks and inconveniences brought by frequent stent replacement, and at the same time, the anti-reflux sheet 13 inside the stent body 1 can effectively prevent urine reflux and effectively avoid discomfort to patients. Embodiment 2
[0031] Embodiment 2 of the present application discloses a manufacturing method of a ureteral stent. The ureteral stent as described in Embodiment 1 is manufactured, including the following steps: S1: First, a biocompatible composite material and nano-titanium dioxide are mixed in a high-speed mixer according to a preset ratio. Preferably, it is composed of a copolymer of poly(lactic-co-glycolic acid) (PLGA) and nano-titanium dioxide. The mixing temperature is 80 - 100 °C, and the time is 10 - 20 min to make the materials evenly dispersed. Then, the mixed material is dried in a vacuum drying oven. The drying temperature is 60 - 80 °C, and the time is 4 - 8 hours to remove moisture and volatile impurities; S2: Use a precision extruder to extrude the dried material into a slender tubular shape. The temperature of the extruder is 200 - 240 °C, the screw speed is 15 - 25 revolutions per minute, and the traction speed is 0.8 - 1.2 meters per minute. During the extrusion process, the corresponding shapes of the renal pelvis end opening 21 and the bladder end opening 31 are formed through the corresponding die. Use laser micro-hole processing technology to process holes in the pipe wall. Use carbon dioxide laser, the laser wavelength is 10.6 μm, the pulse energy is 8 - 15 millijoules, the pulse frequency is 15 - 25 kilohertz, and the scanning speed is 400 - 800 millimeters per second to process micro-holes with a diameter of 0.1 - 0.3 millimeters. Finally, construct a nano-scale rough structure on the outer surfaces of the stent body 1, the renal pelvis end 2, and the bladder end 3 through plasma etching process; S3: Place the whole ureteral stent in a reaction kettle containing a nano-titanium dioxide precursor solution, and uniformly deposit nano-titanium dioxide on the inner and outer surfaces of the whole ureteral stent through chemical deposition method, and then perform annealing treatment on the whole ureteral stent; S4: Dissolve potassium sodium hydrogen citrate and biodegradable polycaprolactone in an organic solvent to prepare a solution with a drug concentration of 10% - 30% (weight ratio). Use the dip coating method to immerse the whole ureteral stent in the solution and slowly lift it at a speed of 5 - 10 centimeters per minute, and then dry it in a vacuum drying oven. The drying temperature is 40 - 60 °C to form a drug sustained-release coating 7 on the surface of the whole ureteral stent.
[0032] The above are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.
Claims
1. A ureteral stent, characterized in that: include The stent body is hollow inside and in the shape of an elongated tube, and the stent body is made of a biocompatible composite material; The renal pelvis end is arranged at one end of the support body and is connected to the support body. The end of the renal pelvis end is provided with a trumpet-shaped renal pelvis end opening; The bladder end is arranged at one end of the support body away from the renal pelvis end and is communicated with the support body. The end of the bladder end is provided with a bladder end opening in a fishtail shape.
2. The ureteral stent according to claim 1, characterized in that: The biocompatible composite material is a mixture of one or more of polylactic acid-glycolic acid copolymer, polylactic acid-caprolactone copolymer, glycolide, polycaprolactone, gelatin, polyurethane, silica gel, polytetrafluoroethylene and expanded polytetrafluoroethylene.
3. The ureteral stent according to claim 1, characterized in that: The outer walls of the stent body, the renal pelvis end and the bladder end are all etched with a nano-scale rough layer.
4. The ureteral stent according to claim 3, characterized in that: The stent body, the renal pelvis end and the bladder end are all uniformly provided with a nano-titanium dioxide coating outside the nano-scale rough layer.
5. The ureteral stent according to claim 4, characterized in that: The stent body, the renal pelvis end and the bladder end are all coated with a drug sustained-release coating outside the nano titanium dioxide coating.
6. The ureteral stent according to claim 1, characterized in that: Through holes are evenly spaced on the tube wall of the support body, and the through holes communicate with the inner and outer spaces of the support body.
7. The ureteral stent according to claim 1, characterized in that: A fixing frame is provided in the hollow interior of the bracket body, and the fixing frame is arranged parallel to the bracket body. The fixing frame divides the internal space of the bracket body into two independent and symmetrical drainage channels, and the two drainage channels are connected at both ends. Two anti-reflux sheets are fixed at both ends of the fixing frame. The two anti-reflux sheets located at the same end are symmetrically distributed relative to the fixing frame and correspond one to one to the drainage channels. The anti-reflux sheets are made of elastic material. Under normal conditions, the anti-reflux sheets gradually bend and tilt away from the fixing frame along the direction from the renal pelvis end to the bladder end. After being compressed, the anti-reflux sheets can bend themselves to conduct or close their corresponding drainage channels.
8. The ureteral stent according to claim 7, characterized in that: The anti-reflux sheet is provided with drainage strips at circumferential intervals at the edge of the anti-reflux sheet away from the fixed frame. The drainage strips are all located in the drainage channel and are all arranged parallel to the fixed frame. The head and tail ends of the drainage strips are simultaneously connected to the two anti-reflux sheets located in the same drainage channel. The two anti-reflux sheets in the same drainage channel move synchronously through the drainage strips.
9. A method for manufacturing a ureteral stent, characterized in that: Manufacturing the ureteral stent according to any one of claims 1 to 8 comprises the following steps: S1: First, the biocompatible composite material and nano-titanium dioxide are mixed in a high-speed mixer according to a preset ratio at a mixing temperature of 80-100°C for 10-20 minutes to uniformly disperse the materials, and then the mixed material is dried in a vacuum drying oven at a drying temperature of 60-80°C for 4-8 hours to remove moisture and volatile impurities; S2: The dried material is extruded into a slender tube using a precision extruder, the extruder temperature is 200-240°C, the screw speed is 15-25 rpm, and the pulling speed is 0.8-1.2 m / min. During the extrusion process, the corresponding shapes of the renal pelvis end opening and the bladder end opening are formed by corresponding dies, and finally a nano-scale rough structure is constructed on the outer surface of the stent body, the renal pelvis end and the bladder end by a plasma etching process; S3: placing the entire ureteral stent in a reactor containing a nano-titanium dioxide precursor solution, uniformly depositing the nano-titanium dioxide on the inner and outer surfaces of the entire ureteral stent by chemical deposition, and then annealing the entire ureteral stent; S4: Sodium potassium hydrogen citrate and biodegradable polycaprolactone are dissolved in an organic solvent to prepare a solution with a drug concentration of 10%-30% (weight ratio). The ureteral stent is immersed in the solution by dip coating, slowly pulled up at a speed of 5-10 cm / min, and then dried in a vacuum drying oven at a drying temperature of 40-60°C to form a drug sustained-release coating on the entire surface of the ureteral stent.