title: Congenital Solitary Kidney in Children: Size Matters.
abstract: OBJECTIVE
  We assessed renal function outcome in children with congenital solitary kidney and evaluated prognostic risk factors.
  
  
  METHODS
  We retrospectively studied the clinical charts of 210 children presenting with congenital solitary kidney at 2 pediatric nephrology and 5 pediatric units between January 2009 and October 2012. Children 0 to 18 years old with a congenital solitary kidney confirmed by scintigraphy were enrolled. Of the patients 146 were suitable for analysis. Median followup was 4.6 years. Primary outcome was decreased estimated glomerular filtration rate, and secondary outcome was occurrence of proteinuria and/or systemic hypertension. Primary outcome-free survival analysis was performed, including multiple regression analysis of significant risk factors.
  
  
  RESULTS
  Decreased estimated glomerular filtration rate was present in 12% of children at a median age of 2.2 years. Primary outcome-free survival analysis revealed an estimated event-free survival of 82% (95% CI 74% to 91%) at 10 years. Estimated survival rate was significantly decreased in children with additional congenital anomalies of the kidney/urinary tract (54% vs 88% overall) or insufficient renal length vs expected for normal congenital solitary kidney. The latter was the strongest predictor of decreased estimated outcome-free survival (49% vs 89%, p <0.001). Occurrence of proteinuria and/or systemic hypertension was present in less than 5% of children.
  
  
  CONCLUSIONS
  Some children with congenital solitary kidney show decreased glomerular filtration rate. Associated anomalies of the kidney/urinary tract and insufficient renal length appear to be significant risk factors. Adequate length of the congenital solitary kidney is a key parameter for maintenance of renal function and should be examined routinely during followup.
authors.affiliation: Nephrology and Dialysis Unit, Department of Pediatrics, Azienda Ospedaliero Universitaria Sant'Orsola-Malpighi, Bologna, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: La Scola
authors.affiliation: Department of Pediatrics, University of Parma, Parma, Italy.
authors.forename: Anita
authors.initials: A
authors.lastname: Ammenti
authors.affiliation: Department of Sciences for Health Promotion and Mother and Child Care, University of Palermo, Palermo, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Puccio
authors.affiliation: Nephrology and Dialysis Unit, Department of Pediatrics, Azienda Ospedaliero Universitaria Sant'Orsola-Malpighi, Bologna, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Lega
authors.affiliation: Nephrology and Dialysis Unit, Department of Pediatrics, Azienda Ospedaliero Universitaria Sant'Orsola-Malpighi, Bologna, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: De Mutiis
authors.affiliation: Nephrology and Dialysis Unit, Department of Pediatrics, Azienda Ospedaliero Universitaria Sant'Orsola-Malpighi, Bologna, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Guiducci
authors.affiliation: Pediatric Unit, Ospedale Mazzoni, Ascoli Piceno, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: De Petris
authors.affiliation: Pediatric Unit, Ospedale S. Bortolo, Vicenza, Italy.
authors.forename: Rosa
authors.initials: R
authors.lastname: Perretta
authors.affiliation: Pediatric Unit, Ospedale Morgagni-Pierantoni, Forlì, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Venturoli
authors.affiliation: Pediatric Unit, Ospedale degli Infermi, Rimini, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Vergine
authors.affiliation: Pediatric Unit, Ospedale di Faenza, Ravenna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Zucchini
authors.affiliation: Pediatric Nephrology and Dialysis Unit, Department of Clinical Sciences and Community Health, University of Milan, Fondazione IRCCS Cà Granda-Ospedale Maggiore Policlinico, Milan, Italy. Electronic address: giovanni.montini@unimi.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Montini
mesh_terms: D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007668:Kidney / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008297:Male; D009929:Organ Size; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D000075529:Solitary Kidney / Q000151:congenital / Q000175:diagnosis* / Q000503:physiopathology; D014463:Ultrasonography / Q000379:methods*
keywords: CAKUT; renal insufficiency, chronic; ultrasonography