title: Numerical analysis of the urine flow in a stented ureter with no peristalsis.
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.
authors.affiliation: Department of Mechanical Engineering, Soongsil University, 369 Sangdo-Ro, Dongjak-gu, Seoul, 156-743, Korea.
authors.forename: Hyoung-Ho
authors.initials: HH
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Boramae Hospital, 425 Shindaebang-2-dong, Dongjak-gu, Seoul,156-707, Korea.
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Urology, Seoul National University Boramae Hospital, 425 Shindaebang-2-dong, Dongjak-gu, Seoul,156-707, Korea.
authors.forename: Seung Bae
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Department of Radiology, Ryokusenkai Yonemori Hospital, 1-7-1, Yojiro, Kagoshima-shi, Kagoshima, 890-0062, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Baba
authors.affiliation: Department of Mechanical Engineering, Soongsil University, 369 Sangdo-Ro, Dongjak-gu, Seoul, 156-743, Korea.
authors.forename: Kyung-Wuk
authors.initials: KW
authors.lastname: Kim
authors.affiliation: Department of Mechanical Engineering, Soongsil University, 369 Sangdo-Ro, Dongjak-gu, Seoul, 156-743, Korea.
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Suh
mesh_terms: D003198:Computer Simulation; D019544:Equipment Failure Analysis; D006801:Humans; D008954:Models, Biological; D010528:Peristalsis / Q000502:physiology*; D011474:Prosthesis Design; D012212:Rheology / Q000379:methods; D015607:Stents; D014513:Ureter / Q000502:physiology* / Q000601:surgery; D014554:Urination / Q000502:physiology*; D014556:Urine / Q000502:physiology*
keywords: CFD; Ureter; flow; numerical analysis; stent