Ureteral calculi in children: what is best as a minimally invasive modality? 
Minimally invasive treatment of ureteral calculi in children is a challenging topic.  In an evidence-based review, we evaluated the efficacy and safety of extracorporeal shock wave lithotripsy (SWL) and ureteroscopic modalities for this group of patients.  In this study, we performed a comprehensive systematic review on articles appeared in the PubMed from 1998 to March 2008.  We selected all papers addressing SWL or ureteroscopic management of the ureteral calculi in children and determined the level of evidence of the presenting data.  Thirty-nine articles were reviewed and 24 with valid information on SWL or ureteroscopic management of the pediatric ureteral calculi were analyzed.  Six articles (25%) were randomized controlled trials and 18 (75%) were retrospective case-controls or case series.  The following data were extracted from the 24 articles: in SWL groups, overall success rate was 84.1% (range, 71% to 100%) for the upper ureteral calculi and 76.2% (range, 19% to 91%) for the lower ureteral calculi.  Only 61% of the patients had only 1 treatment course, while 8% and 31% of the cases required 2 and more than 2 sessions of treatment, respectively.  With ureteroscopic management, the overall success rates were 93.2% (range, 81% to 100%) and 74.4% (range, 20% to 100%) in the lower and upper ureteral calculi, respectively.  The main limitations of the series on minimally invasive treatment of pediatric ureteral calculi are lack of powerful randomized controlled trials or prospective data and insufficient patient numbers.  Therefore, it is difficult to draw absolute conclusions about successful treatment based on current knowledge.