Factors that predict the spontaneous passage of ureteric stones in children

Objective: To study the natural history of stone passage in children with ureterolithiasis and to define factors predictive of spontaneous passage. Patients and methods: In all, 72 children with ureteric stones were evaluated; patients with ureteric calculi of 10 mm were excluded, as were those with absolute indications for surgical stone removal. Stone size, location, side, presence of hydro- nephrosis, perinephric stranding and degree of the tissue-rim sign were estimated by unenhanced helical computed tomography (UHCT). All patients were sent home with no administration of an a-blocker. The stone status was evaluated by a plain abdominal film or CT at approx 6 weeks after the initial diagnostic evaluation. The time from the initial complaint to the passage of the stone was recorded for each patient. Results: In all, 54 (75%) children with ureteric stones of 66 mm eventually passed their stones spontaneously. However, stones of 4 mm and those in the distal ureter had a significantly higher spontaneous passage rate and shorter time to stone pas- sage (P 0.05). The UHCT findings of a higher degree of the tissue-rim sign, hydro- nephrosis and perinephric fat stranding were associated with a lower likelihood of stone passage. Conclusions: The rate of spontaneous passage of ureteric stones in children varies with stone location, and perinephric stranding on UHCT seems to be useful for pre- dicting the possibility of spontaneous passage. In cases with unfavourable signs an early intervention might have better outcomes than conservative therapy.