title: Risk factors associated with chronic kidney disease in patients with posterior urethral valves without prenatal hydronephrosis.
abstract: OBJECTIVE
  Postnatal diagnosis of posterior urethral valves continues despite the prevalence of prenatal ultrasound. We identified risk factors associated with chronic kidney disease in these children.
  
  
  METHODS
  We retrospectively reviewed the medical records of boys with posterior urethral valves with clinical presentations other than prenatal hydronephrosis. We recorded presenting symptoms, age at presentation, and preoperative hydronephrosis and/or vesicoureteral reflux. Chronic kidney disease was defined as previous renal transplantation, dialysis dependence or glomerular filtration rate less than 60 ml per minute/1.73 m(2) at last followup. We used univariate survival analysis with the log rank test of equality for categorical variables and Cox proportional hazard regression for continuous variables to identify risk factors associated with progression to chronic kidney disease.
  
  
  RESULTS
  We identified 141 boys with posterior urethral valves with a postnatal presentation. Median age at presentation was 46 months (range 0.3 to 174). Febrile urinary tract infection in 28% of patients and voiding complaints in 50% were the most common presentations. A total of 12 patients (9%) progressed to chronic kidney disease up to 23 years after initial presentation. Preoperative bilateral hydronephrosis, increased hydronephrosis severity and bilateral vesicoureteral reflux were associated with progression to chronic kidney disease.
  
  
  CONCLUSIONS
  Approximately 10% of cases with postnatal presentation of posterior urethral valves progress to chronic kidney disease, sometimes decades after the initial presentations. Although all patients with posterior urethral valves should be counseled on the potential loss of renal function, children with risk factors warrant close followup into adulthood.
authors.affiliation: Division of Pediatric Urology, Monroe Carell Jr. Children's Hospital at Vanderbilt, Nashville, Tennessee, USA.
authors.forename: Dena L
authors.initials: DL
authors.lastname: Engel
authors.forename: John C
authors.initials: JC
authors.lastname: Pope
authors.forename: Mark C
authors.initials: MC
authors.lastname: Adams
authors.forename: John W
authors.initials: JW
authors.lastname: Brock
authors.forename: John C
authors.initials: JC
authors.lastname: Thomas
authors.forename: Stacy T
authors.initials: ST
authors.lastname: Tanaka
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D006801:Humans; D006869:Hydronephrosis; D007223:Infant; D007674:Kidney Diseases / Q000453:epidemiology*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D014521:Urethra / Q000002:abnormalities*