Long-term effects of extracorporeal shock wave lithotripsy on renal function: Our experience with 156 patients with solitary kidney

Purpose: We studied the long-term impact of shock wave lithotripsy on renal function, stone recurrence and hypertension in patients with a solitary kidney. Patients with a solitary kidney provide a unique opportunity to evaluate any clinically significant change in renal function. Materials and Methods: We retrospectively reviewed the records of 156 patients with stones in a solitary kidney treated with shock wave lithotripsy monotherapy. Treatment outcome was evaluated after 3 months. Long-term followup (more than 12 months) was available for 108 patients. Serum creatinine, systolic and diastolic blood pressure, new onset hypertension, calculated glomerular filtration rate, and kidney morphology were determined before and after treatment, and compared by chi-square, paired and unpaired t tests. Results: After 3 months the overall stone-free rate was 80.8% (126 of 156). Renal obstruction caused by steinstrasse after shock wave lithotripsy occurred in 14 (8.9%) patients. Secondary procedures were required in 20 (12.8%) patients. Followup ranged from I to 16 years with a mean of 3.8 (SD +/- 3.5). After long-term followup the stone-free rate was 76.8% and real stone recurrence developed in 18.5% of patients. There was no significant difference in any evaluated pretreatment or posttreatment parameters. Conclusions: The demonstrated effectiveness, small number of complications at short-term followup, insignificant effect on renal function, blood pressure and relatively small number of recurrences at the long-term followup confirm that shock wave lithotripsy is not only effective but is also safe in the long run.