Factors that predict the spontaneous passage of ureteric stones in children

Abstract

ObjectiveTo study the natural history of stone passage in children with ureterolithiasis and to define factors predictive of spontaneous passage. Patients and methodsIn all, 72 children with ureteric stones were evaluated; patients with ureteric calculi of >10mm were excluded, as were those with absolute indications for surgical stone removal. Stone size, location, side, presence of hydronephrosis, 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 α-blocker. The stone status was evaluated by a plain abdominal film or CT at ≈6weeks after the initial diagnostic evaluation. The time from the initial complaint to the passage of the stone was recorded for each patient. ResultsIn all, 54 (75%) children with ureteric stones of ⩽6mm eventually passed their stones spontaneously. However, stones of <4mm and those in the distal ureter had a significantly higher spontaneous passage rate and shorter time to stone passage (P<0.05). The UHCT findings of a higher degree of the tissue-rim sign, hydronephrosis and perinephric fat stranding were associated with a lower likelihood of stone passage. ConclusionsThe rate of spontaneous passage of ureteric stones in children varies with stone location, and perinephric stranding on UHCT seems to be useful for predicting the possibility of spontaneous passage. In cases with unfavourable signs an early intervention might have better outcomes than conservative therapy.