Islam Md Didarul, Kang Hyo Jeong, Tae Sung Jin, Kim Kyung-Wuk, Choi Young Ho, Lee Seung Bae, Rakibuzzaman Md, Kim Min Uk, Kim Hyoung-Ho
Department of Mechanical Engineering, Graduate School of Engineering, Gyeongsang National University, Jinju, South Korea.
Department of Mechanical Engineering, International University of Business Agriculture and Technology, Dhaka, Bangladesh.
Sci Rep. 2025 Jul 1;15(1):22034. doi: 10.1038/s41598-025-04248-1.
A significant challenge for urological treatment is caused by encrustation that can obstruct urinary drainage. We analyzed the rate of encrustation formation for the initial three weeks in Conventional Double J Stent (CDJS), Renovated Double J Stent (RDJS), and Single J Stent (SJS) under patient-specific control conditions (37 °C, pH 7.8, 60 mL/hr., 50% stenosis). A conceptually designed in vitro urinary tract model representing the kidney, ureter and bladder model is used where the inlet flow rate is controlled with a peristaltic pump, and when the bladder is filled with artificial urine (AU), it is emptied manually, and the time is measured to calculate flow impediments. Stents have been removed from the tract after 21 days to measure mass and scanning electron microscope (SEM) analysis. A Computational Fluid Dynamics (CFD) analysis has been done to show the velocity profile and wall shear stress (WSS) of stents. RDJS has shown the highest flow rate and stable flow performance from the experiment, and SJS exhibited the lowest encrustation with a mass increase of 0.025 g compared to RDJS (0.053 g) and CDJS (0.057 g). The SEM image showed encrustation covered 10.37% of the SJS significantly lower than RDJS (13.04%) and CDJS (13.52%) near the stenosis side holes. The research evidence on SJS demonstrates the least encrustation of SJS stenosis region is further validated through the simulation result which showed a higher wall shear stress (10.4 mPa) for SJS at that location. SJS should be used for short durations for high-risk patients and RDJS for better flow maintenance, which indicates that stent selection should focus on improving the patient's outcomes.
结石形成会阻碍尿液引流，给泌尿外科治疗带来重大挑战。我们在患者特定的控制条件（37°C、pH值7.8、60毫升/小时、50%狭窄）下，分析了传统双J支架（CDJS）、改良双J支架（RDJS）和单J支架（SJS）在最初三周内的结石形成率。使用一个概念设计的体外尿路模型，该模型代表肾脏、输尿管和膀胱模型，通过蠕动泵控制入口流速，当膀胱充满人工尿液（AU）时，手动排空膀胱，并测量时间以计算流动阻力。21天后从尿路中取出支架，测量其质量并进行扫描电子显微镜（SEM）分析。已进行计算流体动力学（CFD）分析以显示支架的速度分布和壁面剪应力（WSS）。实验表明，RDJS的流速最高且流动性能稳定，SJS的结石形成最少，与RDJS（0.053克）和CDJS（0.057克）相比，质量增加了0.025克。SEM图像显示，在狭窄侧孔附近区域，SJS的结石覆盖面积为10.37%，明显低于RDJS（13.04%）和CDJS（13.52%）。关于SJS的研究证据表明，SJS狭窄区域的结石形成最少，这通过模拟结果得到进一步验证：在该位置，SJS的壁面剪应力更高（达到10.4 mPa）。对于高危患者，SJS应短期使用；对于更好地维持尿液流动，应使用RDJS，这表明支架选择应侧重于改善患者的治疗效果。
