Long-term renal functional effects of shock wave lithotripsy, percutaneous nephrolithotomy and combination therapy: a comparative study of patients with solitary kidney.

PURPOSE: We compared the long-term impact on renal function after shock wave lithotripsy, percutaneous nephrolithotomy or the 2 techniques combined in patients with a solitary kidney.

MATERIALS AND METHODS: A total of 45 women and 38 men 15 to 86 years old (mean age 56.1) with a solitary kidney were treated with shock wave lithotripsy (53), percutaneous nephrolithotomy (18) or the 2 techniques combined (12). Before and after treatment serum creatinine, blood pressure and the calculated glomerular filtration rate were determined, and raw and calculated data were compared by the Kruskal-Wallis, Fisher exact and Wilcoxon rank sum tests, and the Spearman correlation coefficient. Followup was 1 to 166.5 months (mean 53.0, median 46.9) overall and statistically equivalent in the 3 treatment arms.

RESULTS: Treatment groups were comparable in regard to patient age, sex distribution, weight, blood pressure and pretreatment serum creatinine. There was no significant difference in any evaluated pretreatment or posttreatment parameters and no difference in the change in any parameter after treatment. Stratifying patients to pretreatment serum creatinine less or greater than 2 mg./dl. likewise revealed no significant difference in the impact on long-term renal function. However, pretreatment serum creatinine positively and strongly correlated with a positive change in the glomerular filtration rate after therapy.

CONCLUSIONS: In this study there was no evidence that any of these 3 treatment modalities resulted in the deterioration of renal function even at long-term followup. This finding implies that shock wave lithotripsy, percutaneous nephrolithotomy and the 2 therapies combined are equally efficacious for preserving renal function when performed in patients with a solitary kidney.