title: Primary vesicoureteral reflux: A 26-year experience in a single centre.
abstract: OBJECTIVE
  To determine the nature of primary vesicoureteral reflux (VUR) and the association of VUR with hydronephrosis and renal damage.
  
  
  METHODS
  The medical records of children ≤ 15 years diagnosed with VUR, attending the Department of Pediatrics, Prince of Songkla University, Thailand between 1987 and 2013 were reviewed. Renal ultrasound and technetium-99m dimercaptosuccinic acid renal scan (DMSA) results were examined to determine the severity of hydronephrosis and renal damage, respectively.
  
  
  RESULTS
  There were 177 boys and 211 girls. 350 (90.2%) were diagnosed following urinary tract infection (UTI). The median (IQR) age at diagnosis of first VUR was 7.6 (4.3-12.2) months in boys and 18.6 (9.0-46.6) months in girls (P < 0.001). Renal ultrasound was performed in 340 patients. Hydronephrosis was found in 105 patients and 135 kidneys and 22.5% VUR kidneys and 11.0% non-VUR kidneys (P = 0.01). The severity of hydronephrosis was associated with VUR grade (44.2% of grades IV and V VUR had hydronephrosis vs 11.9% of grades I-III VUR, P < 0.001). DMSA was performed in 332 patients. Abnormalities were found in 30.1% VUR kidneys and 4.1% non-VUR kidneys (P < 0.001). Abnormal DMSA results were strongly associated with VUR grade (17.8% for VUR grades I-III vs 60.5% for VUR grades IV and V, P < 0.001).
  
  
  CONCLUSIONS
  Primary VUR in this group was most commonly diagnosed following investigation of UTI and detected during infancy, earlier in boys. Hydronephrosis and renal damage were associated with severity of VUR.
authors.affiliation: Department of Pediatrics, Hat Yai, Thailand.
authors.forename: Prayong
authors.identifier: http://orcid.org/0000-0003-3735-1771
authors.initials: P
authors.lastname: Vachvanichsanong
authors.affiliation: Department of Pediatrics, Hat Yai, Thailand.
authors.forename: Pornsak
authors.initials: P
authors.lastname: Dissaneewate
authors.affiliation: Epidemiology Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand.
authors.forename: Edward
authors.initials: E
authors.lastname: McNeil
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006785:Hospitals, University; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000453:epidemiology*; D007223:Infant; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008499:Medical Records; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D017678:Sex Distribution; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D013785:Thailand / Q000453:epidemiology; D013997:Time Factors; D014718:Vesico-Ureteral Reflux / Q000000981:diagnostic imaging / Q000453:epidemiology*
chemical_list: D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid
keywords: children; hydronephrosis; renal damage; urinary tract infection; vesicoureteral reflux