ABSTRACT
Objective To study urodynamic changes of urine at different degrees of hydronephrosis based on computational fluid dynamics (CFD) method, so as evaluate the influence of hydronephrosis degree on kidneys’ ability to discharge stones. Methods Twelve models, including the branched pelvis Model A (normal hydronephrosis A1, mild hydronephrosis A2, medium hydronephrosis A3, severe hydronephrosis A4 models), mature ampullary pelvis Model B (normal hydronephrosis B1, mild hydronephrosis B2, medium hydronephrosis B3, severe hydronephrosis B4 models), and embryo pot abdominal pelvis Model C (normal hydronephrosis C1, mild hydronephrosis C2, medium hydronephrosis C3, severe hydronephrosis C4 models) were established. The urine flow velocity and velocity vector at the neck of the kidney, the outlet of the renal pelvis were calculated by CFD method. Results As the degree of hydronephrosis increased, the flow velocity of urine at the neck of the kidney and the outlet of the renal pelvis decreased. The urinary shearing force of the stones and the kidney’s ability to discharge stones gradually decreased, whereas the circulatory stagnation zone and the velocity boundary layer in kidney aggregate system gradually increased. Conclusions Hydronephrosis can cause changes in urodynamics of the urine. Therefore, the effect of hydronephrosis with different degrees on the patient’s ability to discharge stones after surgery should be fully considered， so as to choose an appropriate treatment method for kidney stones in clinic.
ABSTRACT
Objective:To explore the effect of improved urethral irrigation on urethral stricture in patients with closed bulbar urethral injury.Methods:The clinical data of 65 male patients with closed bulbar urethral injury complicated with difficult catheterization from January 2014 to January 2018 in the First Hospital of Shanxi Medical University were retrospectively analyzed. Among them, 30 cases were treated with flexible cystoscope-guided catheterization and external urethral orifice nursing (routine group), and 35 cases were treated with flexible cystoscope-guided catheterization and urethral drug flushing (improved group). The incidence of urethral stricture 1 and 6 months after catheter removal, number of urethral dilatation and maximum urinary flow rate 6 months after catheter removal, visual analogue score (VAS) during indwelling catheter were compared between 2 groups.Results:Both groups indwelled the catheters successfully. During indwelling catheter, the inflammatory secretion in improved group was less and thinner than that in routine group. There was no significant difference in the incidence of urethral stricture 1 month after catheter removal and VAS during indwelling catheter between 2 groups ( P>0.05); the incidence of urethral stricture and number of urethral dilatation 6 months after catheter removal in improved group were significantly lower than those in routine group: 5.7% (2/35) vs. 26.7% (8/30) and (7.1±1.0) times vs. (11.4±1.8) times, the maximum urinary flow rate 6 months after catheter removal was significantly higher than that in routine group: (19.8 ± 2.9) ml/s vs. (16.3±2.3) ml/s, and there were statistical differences ( P<0.05 or <0.01). Conclusions:The system of improved urethral irrigation can be easily fabricated and can achieve convenient application. This improved treatment can facilitate the discharge of urethral secretions, alleviate the urethral inflammation, reduce the urethral scar formation, and can prevent the incidence of bulbar urethral stricture effectively.