MP47-19: Time to spontaneous resolution in infant stone disease

Sunday, September 12, 2021 8:00 PM to 10:00 PM


Authors: Sean Berquist, Gunjan Agrawal, Justine Dela Cruz, Kathleen Kan, Stanford, CA

Introduction: Urolithiasis is a rising concern in pediatric populations. Infant presentations are unique in their pathophysiology and may often present as incidental findings. We aim to characterize our population of infant stone formers at a single tertiary pediatric hospital in order to inform duration of follow-up and long-term management.

Methods: We utilized our electronic health record to identify patients with a first diagnosis of stone disease before the age of 12 months from 2014-2021. The final cohort (n=53) all had initial stones diagnosed by imaging at our institution with =1 subsequent radiology encounter. Patients with nephrocalcinosis and percutaneous tubes were excluded. History and presentation, radiographic findings, treatment/management and demographic variables were collected.  

Variables were analyzed using descriptive analysis, chi-square, Fisher test and Welch t-tests using R. Outcomes have been grouped into patients with complete resolution (Group 1) or with stones of equivocal or greater size (Group 2) on follow-up ultrasound. Results were considered significant if p < 0.05.

Results: The mean age of diagnosis of urolithiasis in 53 patients (male=37) was 3.25 ± 2.52 months. The duration of follow up ranged from 1-72 months with a mean of 12.67 ± 15.30 months. Most infants were asymptomatic at presentation (64.1%). Among the symptomatic infants, UTI (n=10, 18.8%) was the most common diagnosis followed by fever (n=4, 7%). There was no significant difference between the two groups in terms of gender, stone size, antenatal factors such as hydronephrosis and associated genitourinary abnormalities. Ultrasound at the time of diagnosis showed hydronephrosis (32.1%) and bilateral stones (37.7%) with only 1 patient having ureteral stones (1.9%).  

Mean time to spontaneous resolution was 6.48 ± 5.46 months. The two groups had significant difference with regards to prematurity and history of furosemide intake (p < 0.05). None of the 53 patients required medical treatment.  4 patients, all with a history of prematurity, underwent eventual surgical intervention.

Conclusions: Infants with stones who have a history of prematurity or furosemide exposure may warrant closer follow-up as they are less likely to undergo spontaneous resolution of stone disease. This may be due to intrinsic physiologic and environmental factors related to initial stone formation itself. A meta-analysis may be required to further confirm the relationship between these factors and the rate of stone resolution in children.

Source of Funding: None
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