Purpose: It has been proposed that younger children are less likely to pass renal calculi spontaneously, and that children younger than 10 years are more likely to have an identifiable metabolic abnormality and subsequently a higher risk of recurrence. We report our clinical outcomes in children with urinary calculi, specifically examining these factors.
Materials and methods: We performed a retrospective review of all pediatric patients diagnosed with renal or ureteral calculi at our institution between 2000 and 2007. Of 150 patients evaluated and treated during this period 80 (86 stones) had sufficient followup data to be included. Patients were divided into 2 groups according to age, namely 10 years or younger and older than 10 years. There were 39 patients in the younger group and 41 patients in the older group. Stone size and location, successful passage or intervention, recurrence and 24-hour urine metabolic study results were recorded.
Results: Of the younger cohort stones were ureteral in 43% and renal in 57%. The opposite trend was seen in older patients, with 69% having ureteral and 31% having renal stones (p = 0.02). Mean stone size (greatest dimension) did not differ significantly between the older and younger groups (6.9 mm vs 5.5 mm, p = 0.17). Overall stone passage rate was 34% for younger and 29% for older patients (p = 0.65). No significant mean size differences in passed stones existed between the groups (3.2 mm vs 2.5 mm, p = 0.31). Overall younger vs older ureteral stone passage rate was 37% vs 41% (p = 0.58), and for renal stones it was 32% vs 0%. Stones recurred in 7 younger and 6 older patients.
Conclusions: Younger children were more likely to present with renal stones, while older children had more ureteral stones. Overall children 10 years old or younger are as likely to pass stones as older children. Renal stones are more likely to be successfully managed expectantly in younger children. Metabolic abnormalities and stone recurrences are observed at similar rates between younger and older children.