Double-J stenting is the most common clinical method employed to restore the upper urinary tract drainage, in the presence of a ureteric obstruction. After implant, stents provide an immediate pain relief by decreasing the pressure in the renal pelvis (P). However, their long-term usage can cause infections and encrustations, due to bacterial colonization and crystal deposition on the stent surface, respectively. The performance of double-J stents - and in general of all ureteric stents - is thought to depend significantly on urine flow field within the stented ureter. However very little fundamental research about the role played by fluid dynamic parameters on stent functionality has been conducted so far. These parameters are often difficult to assess in-vivo, requiring the implementation of laborious and expensive experimental protocols. The aim of the present work was therefore to develop an artificial model of the ureter (i.e. ureter model, UM) to mimic the fluid dynamic environment in a stented ureter. The UM was designed to reflect the geometry of pig ureters, and to investigate the values of fluid dynamic viscosity (μ), volumetric flow rate (Q) and severity of ureteric obstruction (OB%) which may cause critical pressures in the renal pelvis. The distributed obstruction derived by the sole stent insertion was also quantified. In addition, flow visualisation experiments and computational simulations were performed in order to further characterise the flow field in the UM. Unique characteristics of the flow dynamics in the obstructed and stented ureter have been revealed with using the developed UM.
Written by:
Clavica F, Zhao X, Elmahdy M, Drake MJ, Zhang X, Carugo D. Are you the author?
Department of Urology, sector FURORE, Erasmus MC, Rotterdam, The Netherlands; Bioengineering Sciences, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom; Bristol Urological Institute, Southmead Hospital, Bristol, United Kingdom; Department of Biomedical Engineering, School of Geosciences and Info-Physics, Central South University, Changsha, China; School of Clinical Science, University of Bristol, Bristol, United Kingdom; Institute for Life Sciences, University of Southampton, Southampton, United Kingdom; Electro-Mechanical Engineering, Faculty of Engineering and the Environment, University of Southampton, Southampton, United Kingdom.
Reference: PLoS One. 2014 Feb 3;9(2):e87433.
doi: 10.1371/journal.pone.0087433
PubMed Abstract
PMID: 24498322
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