title: Observation of infants with SFU grades 3-4 hydronephrosis: worsening drainage with serial diuresis renography indicates surgical intervention and helps prevent loss of renal function.
abstract: OBJECTIVE
  Early pyeloplasty is indicated for ureteropelvic junction obstruction (UPJ) obstructions with reduced differential renal function (DRF) and/or no drainage on diuretic renography (DR). Optimal management of Society of Fetal Urology (SFU) Grades 3 and 4hydronephrosis with preservation of DRF and indeterminate drainage is less straightforward. We review our experience using serial DR to guide the management of kidneys with high-grade hydronephrosis, emphasizing preservation of DRF.
  
  
  METHODS
  After IRB approval we reviewed the charts of 1398 patients <1-year-old referred for prenatal hydronephrosis. Only patients with SFU Grades 3 and 4 hydronephrosis without ureterectasis were included in the study. Initial evaluation included a baseline DR. Follow-up included DR or ultrasound (US).
  
  
  RESULTS
  115 patients (125 kidneys) were eligible for study inclusion. 27 kidneys underwent early surgery (median 64 days) due to reduced DRF and/or severely impaired drainage. 98 kidneys were initially observed. Of these, 21 underwent delayed surgery (median 487 days) due to worsening drainage. Only 2 patients had an irreversible decrease in DRF of >5%. 77 kidneys demonstrated improved drainage and stable DRF. Comparison of observation (n = 77) and surgery groups (n = 48) revealed more kidneys with SFU Grade 3 hydronephrosis in the observation group (p = 0.0001).
  
  
  CONCLUSIONS
  Infants with Grades 3 and 4 hydronephrosis and preserved DRF may be safely followed with serial DR. Patients with SFU Grade 4 hydronephosis are more likely to require surgery. Worsening drainage on serial DR is a useful indicator for surgical intervention which limits the number of pyeloplasties while preserving DRF.
authors.affiliation: Division of Pediatric Urology and Department of Pediatric Radiology, Children's National Medical Center, The George Washington University, Washington, DC, USA. sherry.ross@duke.edu
authors.forename: Sherry S
authors.initials: SS
authors.lastname: Ross
authors.forename: Steve
authors.initials: S
authors.lastname: Kardos
authors.forename: Aaron
authors.initials: A
authors.lastname: Krill
authors.forename: Jason
authors.initials: J
authors.lastname: Bourland
authors.forename: Bruce
authors.initials: B
authors.lastname: Sprague
authors.forename: Massoud
authors.initials: M
authors.lastname: Majd
authors.forename: Hans G
authors.initials: HG
authors.lastname: Pohl
authors.forename: M David
authors.initials: MD
authors.lastname: Gibbons
authors.forename: A Barry
authors.initials: AB
authors.lastname: Belman
authors.forename: H Gil
authors.initials: HG
authors.lastname: Rushton
mesh_terms: D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D007223:Infant; D007682:Kidney Pelvis / Q000601:surgery*; D008297:Male; D011859:Radiography; D011866:Radioisotope Renography / Q000379:methods*; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal; D013520:Urologic Surgical Procedures / Q000379:methods