Relationship between the Success of Extracorporeal Shock Wave Lithotripsy (ESWL) and the Degree of Hydronephrosis when Treating Patients with Upper Ureteral Stones

Abstract

Purpose: We tried to determine the relation between the degree ofstoneinduced hydronephrosis and the outcome of extracorporeal shock wave lithotripsy (ESWL) when treating patients with solitary upper ureteral stone. Materials and Methods: 260 proximal ureteral stone patients with or without hydronephrosis were treated with ESWL between January 2003 and December 2006 and 8 of these patients were lost to follow up. The degree of hydronephrosis was defined by performing renal ultrasound. The patients were divided into four groups according to the degree of hydronephrosis. Group 0 (n=30) had no urinary system dilatation, group 1 (n=123) had a mild dilatation of the renal pelvis but no renal calices, group 2 (n=75) had a moderate dilatation of the renal pelvis and group 3 (n=24) had a severe dilatation of the renal pelvis and calices. In addition to the degree of hydronephrosis, the stone size, number of sessions, number of shockwave treatments applied and the success rate of ESWL were recorded. Results: The success rate after ESWL treatment was 92.9% (n=234). There were no statistically significant differences among the groups for the stone size, number of sessions and number of applied shockwave treatments. There were a trend for a decreased success rate of ESWL with an increased degree of hydronephrosis, but this did not reach statistical significance (p=0.436). After ESWL, a few patients encountered minor complications such as gross hematuria, flank pain, stone street, fever and perirenal hematoma. Yet most cases were treated conservatively and there was no need for hospitalization. Conclusions: For the patients in our study who had a solitary calculus in the upper ureter, the degree of hydronephrosis caused by the stone does not affect the success rate after ESWL. (Korean J Urol 2007;48:422-427)