关键词: 输尿管支架, 结壳, 生物膜, 聚氨酯, 亲水涂层

Abstract: Objective To conduct a comparative study on the encrustation of three types of ureteral stents under in vitro conditions. Methods The three groups of ureteral stents—hydrophilic-coated ureteral stents, imported non-coated ureteral stents, and domestic non-coated ureteral stents—were evenly divided into 1 cm segments. Subsequently, the segments of the three groups of ureteral stents were immersed in artificial urine for 2, 4, 6, 8, 10, and 12 weeks. After the sample preparation was completed, the outer surfaces and cross-sections of the three groups of ureteral stents were first scanned using a scanning electron microscope （SEM）. Secondly, based on the SEM, an energy-dispersive spectrometer （EDS） was used to analyze the inorganic elements in the encrustation of the regions of interest. Finally, the encrustation was fully dissolved in 5% nitric acid solution, and an automatic biochemical analyzer was employed to measure the concentrations of calcium, phosphate, magnesium, and other ions in the solution. Results The scanning electron microscopy （SEM） images and biochemical analysis results indicated that the encrustation on all three groups of ureteral stents increased with prolonged indwelling time. At the 2-week time point, there was no significant difference in the encrustation mass among the three groups of ureteral stents. Starting from the 4-week time point, the mass of inorganic elements on the hydrophilic-coated stents was significantly greater than that on the imported non-coated stents and the domestic non-coated stents （P<0.01）. Conclusion As the retention time of ureteral stents increases, the amount of crusting progressively increases. Hydrophilic coating materials may promote surface crusting of polyurethane ureteral stents. It is recommended to clinically monitor the retention time of ureteral stents.

Key words: ureteral stents, encrustatio, biofilm, polyurethane, hydrophilic coating