We report 3 cases in which ureteral
stents were indwelt to treat
hydronephrosis due to
retroperitoneal fibrosis, resulting in aggravation of
hydronephrosis and renal function. An urodynamic study was carried out to determine the factors that aggravated
hydronephrosis. The subjects were a 59-year-old male with
prostatic cancer and bilateral
hydronephrosis due to intrapelvic
lymph node metastasis, a 49-year-old female with retroperitoneal
lymph node metastasis and bilateral
hydronephrosis following surgery for
stomach cancer, and a 65-year-old male with
hydronephrosis due to
idiopathic retroperitoneal fibrosis. Indwelling of ureteral
stents in the 3 patients resulted in aggravation of
hydronephrosis and renal function.
Stent indwelling models of
retroperitoneal fibrosis were produced using adult mongrel dogs. A pressure flow study was carried out through the
nephrostomy in each experimental model to determine the intrapelvic pressure and urine volume. In all
stent indwelling models, the urine volume showed changes similar to those in the controls. In the
stent indwelling models, the intrapelvic pressure showed a significant increase with an increase in the volume of water instilled through the
nephrostomy in the
stent indwelling models with
retroperitoneal fibrosis, unlike the controls and models with ureteral
stenosis. In conclusion, the clinical cases and model experiment suggested that unlike partial ureteral
stenosis, in ureters in which extensibility was disturbed in an extensive area, the indwelt
stent caused an increase in the resistance of the liquid flowing in the ureter, aggravating
hydronephrosis.