title: Pelvi-ureteric junction obstruction in duplex kidneys.
abstract: OBJECTIVE
  To report our experience of 11 children with pelvi-ureteric junction obstruction (PUJO) in a duplex kidney and to review previous reports.
  
  
  METHODS
  From 1995 to 2005 the second author (G.H.H.S.) performed 145 pyeloplasties in single-system kidneys and in 11 children with PUJO in a duplex kidney. Upper and lower pole obstructions were found in both complete and incomplete duplicated systems. Investigations included renal ultrasonography, renal scintigraphy, micturating cystography, cystoscopy and retrograde pyelography. Ten patients had surgery (eight dismembered pyeloplasties, one upper-pole heminephrectomy, one pyelo-ureterostomy).
  
  
  RESULTS
  Three children had obstruction of the upper moiety and eight had obstruction of the lower moiety. Upper and lower pole obstructions were found in both complete and incomplete duplicated systems.
  
  
  CONCLUSIONS
  Upper-pole obstruction in a duplex kidney is rare; the present series suggests that it is more common than previously reported.
authors.affiliation: Urology, The Children's Hospital at Westmead, NSW, Australia.
authors.forename: Maya
authors.initials: M
authors.lastname: Horst
authors.forename: Grahame H H
authors.initials: GH
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D011446:Prospective Studies; D011859:Radiography; D014513:Ureter / Q000000981:diagnostic imaging / Q000601:surgery*; D014517:Ureteral Obstruction / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*