title: Factors that predict the spontaneous passage of ureteric stones in children.
abstract: OBJECTIVE
  To study the natural history of stone passage in children with ureterolithiasis and to define factors predictive of spontaneous passage.
  
  
  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 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 ≈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 ⩽6 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 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.
  
  
  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 predicting the possibility of spontaneous passage. In cases with unfavourable signs an early intervention might have better outcomes than conservative therapy.
authors.affiliation: Section of Paediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Mokhless
authors.affiliation: Section of Paediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt.
authors.forename: Abdel-Rahman
authors.initials: AR
authors.lastname: Zahran
authors.affiliation: Section of Paediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Youssif
authors.affiliation: Section of Paediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt.
authors.forename: Khaled
authors.initials: K
authors.lastname: Fouda
authors.affiliation: Section of Paediatric Urology, Department of Urology, Alexandria University, Alexandria, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Fahmy
keywords: Paediatric urolithiasis; Stones; TRS, tissue rim sign; UHCT, unenhanced helical CT; Ureter