Role of Metabolic Evaluation and Specific Prophylaxis in the Long-Term Outcome of Extracorporeal Shock Wave Lithotripsy in Children*

Abstract

Children (28 boys, 24 girls) with an average age of 10.1 years (range 2–17) who underwent 63 sessions of extracorporeal shock wave lithotripsy for 64 urinary stones (57 renal, 7 ureteral) between 1984 and 1991 have been evaluated with special regard to long-term recurrences and stone regrowth. The first 10 patients were treated on a Dornier HM3, the rest on the Siemens Lithostar. Of the 52 patients, 35 were first-time stone formers, and 17 had recurrent disease. A uniform metabolic evaluation with 24-hour urinalysis was not performed in all patients. Fourteen children received urinary calcium analysis according to Pak's test. After 3 months, 93% were either stone free or had a residual stone mass of less than 3 mm. Within an average follow-up of 39.3 (9–80) months, 74% were stone free, 9.5% had recurrences, and 17% showed regrowth. Only 1 of 16 patients who received specific prophylaxis for hypercalciuria (n = 6), cystinuria (n = 6), or infection stones (n = 4) developed new stone episodes, while the other 10 patients with either recurrence or regrowth belonged to the no-prophylaxis group. We think that all children with urolithiasis should undergo a metabolic evaluation and have specific prophylaxis to enhance the long-term stone-free rate following SWL.