Publications by authors named "Kyung-Wuk Kim"
Article Synopsis
- The study compared renovated double J stents (DJS) with conventional stents using ureter models to assess their effectiveness for different ureteral diseases.
- Two ureter models were tested: one with stenosis and one without, using various sizes and designs of DJS to evaluate urine flow.
- Results showed that renovated stents had better flow rates in models without stenosis but did not perform significantly better than conventional stents in models with stenosis.
Background: Iatrogenic femoral artery pseudoaneurysm (IFP) incidence is increasing with increase in diagnostic and therapeutic angiography, and so, the less invasive percutaneous thrombin injection (PTI) is the most widely used treatment. Moreover, studies that minimize PTI complications and highlight therapeutic effects are lacking.
Objectives: This study performed in vitro thrombosis modeling of pseudoaneurysms and analyzed thrombosis within and thromboembolism outside the sac during thrombin injection.
Effects of size and shape of the side holes of a double J stent on the ureter fluid flow after stenosis.
Comput Methods Biomech Biomed Engin
September 2024
Article Synopsis
- The study used computational fluid dynamics (CFD) to analyze how different side hole sizes in double J stents (DJS) affect their encrustation in the presence of ureteral stenosis.
- It looked at side holes with varying diameters and how they influenced urine flow rates, shear stress, and wall shear stress (WSS) under different degrees of stenosis (0%, 12%, 88%).
- Results indicated that larger side holes increase flow rates and reduce encrustation, particularly beneficial for patients with urinary stones, especially with a 12% stenosis where flow rates doubled.
Purpose: To evaluate the formation of encrustation on double J stents (DJSs) using artificial urine.
Materials And Methods: In this study, a static urinary system containing artificial urine was created, and a total of 45 DJSs were used to evaluate the formation of encrustation. Three groups of 15 DJSs were tested for 4, 8, or 14 weeks.
Objective: This study investigates the effects of vesicoureteral reflux (VUR) in the upper and lower urinary tracts with and without ureteral stenosis and with a double J stent (DJS).
Methods: The entire length of the urinary tract with an implanted DJS was modeled. To assess the possibility of VUR, the measured values were used as boundary conditions for the baseline, the maximum cystometric bladder capacity (MCBC) during the filling phase, and maximum vesical pressure during the voiding phase were computed.
Article Synopsis
- The study investigates the use of computational fluid dynamics (CFD) to optimize percutaneous thrombin injection (PTI) for treating femoral artery pseudoaneurysms (FAP).
- The analysis recommends that the needle be placed at the center of the aneurysm during the initial inflow phase of blood for effective treatment.
- The clinical results show a 100% success rate for PTI, with no complications or embolism detected in patients, and confirmed complete thrombosis of the pseudoaneurysms through follow-up CT scans.
Urine flow analysis using double J stents of various sizes in in vitro ureter models.
Int J Numer Method Biomed Eng
February 2020
Article Synopsis
- A double J stent (DJS) is used to relieve urine buildup in the upper urinary tract due to ureteral stenosis, which can lead to renal failure.
- The study tested various sizes of DJSs (from 5Fr to 8Fr) in silicone ureter models without stenosis to evaluate their effectiveness in promoting urine flow.
- Results showed that the smaller 5Fr DJS had higher total flow rates compared to larger sizes, and computational fluid dynamics confirmed that the experimental findings were consistent with the numerical analysis.
Article Synopsis
- The ureter allows urine to travel from the kidneys to the bladder, with flow aided by peristalsis and hydrostatic pressure.
- Ureteral diseases and the use of double J stents can disrupt normal urine flow, leading to various shapes of the ureter, like a tube or funnel.
- This study created models of differently shaped ureters to analyze how their shapes and the presence of stents affect urine flow rates and patterns.
Article Synopsis
- * A study explored the impact of side holes in double J stents on urine flow, specifically using models that mimic human anatomy instead of straight ureters.
- * Findings revealed that side holes improved urine flow rates in cases of ureteral stenosis, particularly as the severity of the stenosis increased, although their angular positioning did not influence the flow rates.
Article Synopsis
- The study compared two surgical techniques (conventional MMA and modified MMA-ASSO) for treating obstructive sleep apnea syndrome (OSAS) using advanced 3D airflow analysis.
- Two male patients with OSAS underwent these techniques, and their airway changes were evaluated before and after surgery using computed tomography and polysomnography.
- Results showed that both methods improved airway function, but the modified MMA-ASSO provided greater benefits in reducing apnea episodes and enhancing airflow dynamics, suggesting it as a promising option for treatment.
Article Synopsis
- A double J stent is commonly used for patients with ureteral stenosis or kidney stones, featuring multiple side holes for urine flow.
- Research evaluated the flow rate and patterns around these side holes using models that mimic both curved and straight ureters.
- Results showed that stents with more side holes had higher total flow rates and that the curved ureter model demonstrated more active inflow and outflow compared to straight models, indicating flow occurs even without obstructions.
Article Synopsis
- - Ureteral stenosis can obstruct urine flow and lead to renal failure, with ureteral stents used to alleviate this issue by enabling urine to flow more freely in the upper urinary tract.
- - The insertion of a stent can weaken ureteral peristalsis over time, causing the ureter to appear tubular and curved rather than functioning normally.
- - A study involving 12 stent models (six curved and six straight) highlighted that curved stent designs, which mimic human anatomy, are more effective for simulating and improving urine flow in computational fluid dynamics (CFD) evaluations.