Pediatric urolithiasis: experience at a tertiary care pediatric hospital

Objective: We aimed to determine the epidemiology, risk factors, clinical characteristics, evaluation and course of patients with urolithiasis at the Children’s Hospital of Eastern Ontario to improve current diagnostic and management strategies. Methods: This was a retrospective study of children with newly identified urolithiasis between Jan. 1, 1999, and July 31, 2004. Cases were reviewed for demographics, presentation, family history, diagnostic methods and findings, metabolic and anatomic abnormalities, management, stone analysis and stone recurrence. Results: Seventy-two patients (40 male, 32 female; mean age 11.3 yr) were assessed. Mean follow-up was at 1.5 years. Eighteen patients (25%) had a family history of stones. Flank pain (63%) was the most common presentation. Eighty-two percent of urinalyses showed microscopic hematuria. Imaging comprised abdominal plain film radiography (56%) and (or) abdominal ultrasonography (74%). The mean stone size was 5 mm. Forty-one percent (28/69) of patients who underwent metabolic investigation had an abnormality. Fourteen percent of patients (10/72) had a genitourinary anatomical abnormality. Thirty-four patients (47%) passed their stones spontaneously, 25 patients (35%) required surgical intervention and 13 patients (18%) had yet to pass their stone. The mean size of spontaneously passed stones was 4 mm. Of 42 stones analyzed, 39 (93%) were composed of calcium oxalate or phosphate. Seventeen (24%) patients had stone recurrence during follow-up. Conclusion: Pediatric patients with stones present in a manner similar to adults. Abdominal plain film radiography and ultrasonography are the preferred initial radiological investigations in children as they limit radiation exposure. Metabolic abnormalities are common and may coexist with anatomic abnormalities, therefore investigations must rule these out. One-half of patients will pass their stones spontaneously. Recurrence rates are high and long-term follow-up is recommended.