Nephrolithiasis in pediatric patients: metabolic and anatomical investigation.

UNLABELLED: Metabolic disorders are frequently observed in pediatric patients with renal lithiasis. OBJECTIVES: Study the metabolic and anatomical alterations and perform the chemical analysis of stones found in children with nephrolithiasis in our region. METHODS: A retrospective study on 158 children with evidence of recent renal stone formation was performed. One hundred and nine children concluded the metabolic study. Laboratory investigation consisted in two samples of 24-hour urine for calcium, uric acid, citrate, oxalate, sodium and creatinine; qualitative cystinuria, urinary pH following 12-hour fasting and water restriction, urine culture and chemical analysis when the stones were available. Renal imaging techniques included, at least, renal ultrasound and excretory urogram. RESULTS: A cause for nephrolithiasis was identified in 96.3% of children. The main metabolic alteration was hypercalciuria (73.4%). Chemical analysis of stones showed calcium oxalate in 90.9% of the cases. Anatomical alterations were found in 18.0% of the investigated cases and the most frequently found alteration was pyelo-ureteral duplication (28.6%). CONCLUSIONS: Hypercalciuria was the most frequently found disorder and pyelo-ureteral duplication was the most common anatomical alteration; moreover, calcium oxalate was the most frequent chemical constituent. The present study showed the characteristics of pediatric patients with nephrolithiasis in our region.