Is medical treatment necessary for infants with small urinary stones?

Urinary stone disease is a common condition. We investigated the usefulness of medical treatment for infants with urinary stones 5 mm or smaller. The study included 197 infants (86 girls and 111 boys) with urolithiasis ≤ 5 mm who were referred to our Department of Nephrology between 2014 and 2016. Infants with metabolic or anatomical risk factors requiring medical treatment were excluded from the study. We retrospectively reviewed urine and serum metabolic profiles and compared stone resolution rates in patients who did and did not receive treatment. The mean age at diagnosis was 5.2 months (range, 14 days to 12 months). The most common complaint was restlessness (n = 92, 46.7%), and 49 infants (24.9%) were asymptomatic. Multiple stones were detected in 166 infants (84.3%). Hypomagnesuria, hypocitraturia, and hypercalciuria were present in 25.3, 19.7, and 18.7% of patients, respectively. Stones < 3 mm (microlithiasis) were detected in 97 infants (49.2%), and 100 (50.8%) patients had 3–5 mm stones. In total, 130 infants (66.5%) received regular treatment and 67 (33.5%) were not treated. Stone resolution was significantly higher in the group receiving K-citrate treatment at the 6th month follow-up, while there were no significantly difference between the two groups at the 12th month control. No previous studies have investigated treatment outcomes in infants with 3–5 mm urinary stones. According to our results, K-citrate treatment may accelerate the resolution of the stone in infants with stones smaller than 5 mm.