A Numerical Simulation of Peristaltic motion in the Ureter Using Fluid Structure Interactions

Vahidi, Behrooz; Fatouraee, Nasser

doi:10.1109/iembs.2007.4352504

Cited by 14 publications

(19 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Numerical analysis has been used for the evaluation of a double J stent in the ureter, and the models for the analysis were models of a straight ureter [4][5][6]. However, the ureter in the human body is not straight but curved due to its location in the abdominal and pelvic cavities.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of the effect of side holes of a double J stent on flow rate and pattern

Kim

Choi

Lee

et al. 2015

BME

View full text Add to dashboard Cite

Abstract.A double J stent has been used widely these days for patients with a ureteral stenosis or with renal stones and lithotripsy. The stent has multiple side holes in the shaft, which supply detours for urine flow. Even though medical companies produce various forms of double J stents that have different numbers and positions of side holes in the stent, the function of side holes in fluid dynamics has not been studied well. Here, the flow rate and pattern around the side holes of a double J stent were evaluated in curved models of a stented ureter based on the human anatomy and straight models for comparison. The total flow rate was higher in the stent with a greater number of side holes. The inflow and outflow to the stent through the side holes in the curved ureter was more active than in the straight ureter, which means the flow through side holes exists even in the ureter without ureteral stenosis or occlusion and even in the straight ureter. When the diameter of the ureter changed, the in-stent flow rate in the ureter did not change and the extraluminal flow rate was higher in the ureter with a greater diameter.

show abstract

Section: Introductionmentioning

confidence: 99%

Numerical analysis of the effect of side holes of a double J stent on flow rate and pattern

Kim

Choi

Lee

et al. 2015

BME

View full text Add to dashboard Cite

show abstract

“…Ureteral peristalsis controls urine transport from the kidney to the bladder partially, along with hydrodynamic forces [1]. A stenosis or occlusion in the ureter by benign or malignant diseases induces insufficient urine flow from the kidney to the bladder, despite peristaltic efforts, resulting in renal failure.…”

Section: Introductionmentioning

confidence: 99%

“…However, the model was not based on the human ureter anatomy, especially the ureter curvature in the human body and the ureter diameter in a condition of no ureteral peristalsis. Here, it was considered that the ureter behaves as a non-uniform passively distensible tube in the absence of peristalsis [1] and data from human beings were collected. We made the model of a stented ureter and analyzed the flow rate and pattern of the model.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of the urine flow in a stented ureter with no peristalsis

Kim

Choi

Lee

et al. 2015

BME

View full text Add to dashboard Cite

Abstract.A ureteral stenosis or occlusion causes the disturbance of normal urine flow and results in renal failure. Ureteral stents are used to relieve the stagnation of urine in the upper urinary tract. Peristalsis in the ureter, which occurs to help urine flow, becomes to weaken when a stent is inserted and effective peristalsis disappears as time goes on, and a stented ureter seems to be tubular and curved in the human body. Double J stents, which are manufactured by many medical companies and are used widely these days, have different geometries of side holes in the stent shafts. In total, 12 models-six curved models of a stented ureter according to different numbers and positions of side holes and ureteral and stent stenoses and another six straight models for comparison with the curved ones-were made based on the data collected from 19 men. The flow rate and pattern in the stented ureter were evaluated using computational fluid dynamics (CFD). According to the results, curved models reflecting the human anatomy seem to be more desirable in the CFD simulation of urine flow and must be good for evaluating the effect of geometrical variations in stent design on urine flow.

show abstract

“…Tissue damage to the ureter wall or obstruction in the vessel will greatly impede healthy flow. A blocked ureter could result in high pressures within the kidney, possibly causing infection/or and kidney failure [4][5]. When adequate flow cannot be produced or a blockage is unable to be removed, a stent is typically used to relieve the strain on both the ureter and kidney [1,[4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…It is assumed that the axial orientation of the stent and ureter are concentric and axially symmetric. The stent is treated as a rigid cylinder with passages to the annulus region having the same diameter as the bore, where the ureter wall is a linear distensible representation [5]. Model physics are fully coupled to allow complete fluid structure interaction between material domains.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Peristaltic Urine Flow in a Stented Ureter

Bevan¹,

Carriveaul²,

Goneau

et al. 2012

Am. J. Biomed. Sci.

View full text Add to dashboard Cite

The capacity of ureteral stents to enhance the conveyance of urine from kidney to bladder is the critical function for patients that require them. The flow path in and around the stent is not a trivial one, particularly if some elements of peristalsis are present in the ureter. This paper details a numerical flow simulation for an axially symmetric stented ureter segment. The flow of urine through a stented, elastically-modeled ureter was considered under varying pressure gradients, bore (lumen) obstructions, and peristaltic deflections (waves). Peristaltic waves are combined with the pressure gradient developed between the kidney and bladder to provide a more accurate representation of the complex flow mechanics found within the ureter. Although it is recognized that peristalsis ceases or diminishes greatly after prolonged presence of a stent, in the time frame that it is active, detrimental consequences like reflux may occur. Several relationships from varying control parameters are determined to predict the onset of reflux as flow conditions within the ureter change. It was determined that occurrence of reflux is more likely as the peristaltic deflection or the obstruction of the stent bore increases. The threat of reflux is low if the pressure gradient between the kidney and bladder remains large. These simulations provide insight into the fluid behaviour within a stented ureter that could lead to optimized stent designs and reduce the possibility of reflux, infection, and discomfort.

show abstract

A Numerical Simulation of Peristaltic motion in the Ureter Using Fluid Structure Interactions

Cited by 14 publications

References 4 publications

Numerical analysis of the effect of side holes of a double J stent on flow rate and pattern

Numerical analysis of the effect of side holes of a double J stent on flow rate and pattern

Numerical analysis of the urine flow in a stented ureter with no peristalsis

Numerical Simulation of Peristaltic Urine Flow in a Stented Ureter

Contact Info

Product

Resources

About