What predicts spontaneous passage of ≤1 cm ureteral stones in children?

PURPOSE: The aim of this study is to determine what factors predict spontaneous passage of ≤1 cm ureteral stones in children. METHODS: Files of the patients diagnosed with a single ureteral stone on a given side between 2008 and 2017 were retrospectively reviewed. Patients with congenital obstructive uropathy, neurogenic bladder, vesicoureteral reflux and those with a stone diameter of >1 cm were excluded. Detection of ureteral stones was done using ultrasonography (US) primarily, and computed tomography when US findings were inconclusive. Patients were treated either conservatively or surgically. Conservative treatment included adequate hydration and pain management whereas surgical treatment included ureteroscopic intervention. Apart from those who required urgent intervention, patients were referred for surgical treatment after 2-4 weeks of follow-up with no spontaneous passage. Factors analyzed for association of spontaneous passage included age, gender, type of hematuria, stone localization, laterality, presence of concomitant kidney stone, degree of hydronephrosis, stone size and stone composition. RESULTS: A total of 70 patients (38 males, 32 females); median age 4.7 years had a ≤ 1 cm ureteral stone (median diameter 7 mm). US was able to diagnose the ureteric stone in 47 patients while computed tomography was required in 23 patients. Spontaneous passage was observed in 40 patients (57.1%). Median time for stone passage was 8 days (3-34 days). Stone size and presence of hematuria (macroscopic and microscopic combined) were factors associated with spontaneous passage and 6.7 mm was found to be the cut-off (AUC = 0.953; 95% CI 0.905-1.000; sensitivity 96.7%, specificity 82.5%, p < 0.001). Moreover, age, degree of hydronephrosis or stone location were not associated with spontaneous passage. CONCLUSION: Patients with a ureteric stone size <6.7 mm can safely be followed conservatively, with a spontaneous passage rate of 82.5%. Type of Study Case series with no comparison group. Level of Evidence IV.

Time to resolution of isolated antenatal hydronephrosis with anteroposterior diameter ≤ 20 mm.

Data regarding spontaneous resolution of mild hydronephrosis consist of different etiologies, and hence, it is heterogeneous. The aim of this study is to evaluate spontaneous resolution rates and the time to complete resolution of antenatally detected isolated hydronephrosis in patients with renal pelvis antero-posterior diameter (RPAPD) ≤ 20 mm. Retrospective chart review of patients who were admitted to our pediatric nephrology clinic for the evaluation of antenatal hydronephrosis between 2011 and 2017 was conducted. Patients that had hydronephrosis with RPAPD ≤ 20 mm, < SFU (Society for Fetal Urology) grade IV on initial postnatal evaluation, and ≥ 3 months of follow-up with at least two renal ultrasounds (US) were included. Complete resolution of hydronephrosis was regarded as SFU grade 0 with a RPAPD of < 7 mm. Patients with ureteric and lower urinary tract abnormalities were excluded. There were a total of 276 patients who met the inclusion criteria. Median follow-up was 16 months (range 3-96 months). Hydronephrosis completely resolved in 198 patients (71.7%). Surgery was not required in any of the patients; however, nine patients (3.3%) showed progression to higher grades of hydronephrosis or increase in AP diameter. Median time to complete resolution of hydronephrosis was 6 months (range 2-35 months) in our study. Those with AP diameter < 10 mm became normal in median of 5 months, while it took median 11 months for patients with AP diameter 10-20 mm to become normalized (p < 0.001).Conclusion: Isolated antenatal hydronephrosis with RPAPD ≤ 20 mm would spontaneously resolve in 71.7% of the cases. Resolution may be expected to happen in 3 years, while the majority will take place in the first year of life. What is Known: • Antenatal hydronephrosis comprises an important amount of clinical visits. • Spontaneous resolution rates differ for various etiologies. What is New: • Isolated antenatal hydronephrosis with RPAPD ≤ 20 mm completely resolves within 3 years in approximately 72% of the cases. • Resolution can be observed within the first year of life in most of the cases.