title: The role of diuretic renography in the evaluation of obstructed hydronephrosis after pediatric pyeloplasty.
abstract: BACKGROUND
  The purpose of this study was to clarify the value of renal drainage half-time in the evaluation of pediatric hydronephrosis after dismembered pyeloplasty.
  
  
  METHODS
  We reviewed the records of 30 children who underwent dismembered pyeloplasty for unilateral ureteropelvic junction obstruction with no other associated urological abnormality. The follow-up duration was more than 5 years for all patients. Pre- and postoperative evaluation included technetium-99m dimercaptosuccinic acid (99mTc-DMSA) renal scan, technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA) diuretic renography, and ultrasonographic examination. According to postoperative renal drainage half-time on diuretic renography, patients were divided into 2 groups: group A with normal renal drainage and group B with prolonged renal drainage for evaluation of their renal functional status.
  
  
  RESULTS
  Postoperative diuretic renography revealed normal drainage (group A) in 54% of patients and prolonged drainage (group B) in 46%. The anteroposterior diameter (APD) of the renal pelvis of all patients showed improvement after pyeloplasty. There was no significant difference in improvement of the renal pelvic APD between the 2 groups. Furthermore, 92% of group A and 91% of group B maintained stable or had improved differential renal function (DRF) postoperatively.
  
  
  CONCLUSIONS
  Drainage half-time is not a reliable parameter for diagnosing obstructed hydronephrosis after pediatric pyeloplasty. We suggest that the renal pelvic APD and DRF should be considered when postoperative obstructed hydronephrosis is diagnosed using the criterion of prolonged renal drainage half-time on diuretic renography.
authors.affiliation: Department of Urology, Chang Gung Memorial Hospital, Taipei, Taiwan 333, R.O.C. taminwang@yahoo.com.tw
authors.forename: Ta-Min
authors.initials: TM
authors.lastname: Wang
authors.forename: Phei-Lang
authors.initials: PL
authors.lastname: Chang
authors.forename: Pan-Fu
authors.initials: PF
authors.lastname: Kao
authors.forename: Ming-Li
authors.initials: ML
authors.lastname: Hsieh
authors.forename: Shih-Tsung
authors.initials: ST
authors.lastname: Huang
authors.forename: Ke-Hung
authors.initials: KH
authors.lastname: Tsui
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging / Q000601:surgery*; D007677:Kidney Function Tests; D008297:Male; D011182:Postoperative Care; D011866:Radioisotope Renography / Q000379:methods*; D012189:Retrospective Studies; D016284:Technetium Tc 99m Pentetate; D016896:Treatment Outcome; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging / Q000601:surgery*; D014567:Urography
chemical_list: D016284:Technetium Tc 99m Pentetate