Extracorporeal shock wave lithotripsy in children. Efficacy, complications and long-term follow-up

Extracorporeal shock wave lithotripsy (ESWL) is effective and safe for the treatment of upper urinary tract calculi in adults. Some speculations concerning possible damages from ESWL on the growing kidney have been raised.

From January 1990 to December 1998, 64 children (30 girls and 34 boys; 8 months to 15 years old, mean 5.6 years) with a total of 83 stones of the upper urinary tract were treated by ESWL (Lithostar). Preoperative evaluation included history, physical examination, routine blood tests, urinalysis, urine culture, intravenous urography and optional renal scintigraphy. The impulse rate per treatment varied from 750 to 4,000 (mean 2,996). After acute treatment, routine follow-up included renal ultrasound, blood pressure controls, laboratory tests and eventually plain film X-ray.

Successful fragmentation of the stones was achieved in all patients. In 54% the patients were free of stones treated at the time of discharge. At 3 months after treatment radiographic studies showed no residual fragments in 80% of the treated children. 83% of the treated stones were cleared entirely. The remaining fragments were clinically insignificant. An average of 2.5 ESWL treatments per child in general anesthesia were required. Stone analysis showed 20 calcium oxalate, 38 calcium phosphate, 12 struvite, 2 uric acid and 9 cystine calculi. Ureteral stents were placed in 43%. No significant urinary infection was seen under antibiotic prophylaxis. Only 3 children showed a recurrence (1 x cystinuria with low compliance and 2 x struvite). There was no case of renal scarring. No change in renal function or blood pressure was found compared to the preoperative values. Hematuria and proteinuria disappeared in all children who were free of stones. Renal ultrasound revealed no growth difference between treated and untreated renal units.

In childhood, ESWL is an efficacious and safe treatment of stones of the upper urinary tract. The long-term follow-up after ESWL with a second-generation lithotriptor did not show any signs of damage to the growing kidney. Sometimes repeated ESWL treatments are justified by the low rate of complications.