PEDIATRIC UROLOGY

doi: 10.1590/S1677-553820100003000029

Predictive factors for acute renal cortical scintigraphic lesion and ultimate scar formation in children with first febrile urinary tract infection
Oh MM, Cheon J, Kang SH, Park HS, Lee JG, Moon du G
Department of Urology, Korea University Medical Center, Seoul, Korea
J Urol. 2010; 183: 1146-50

• Purpose: We assessed predictive factors for acute renal cortical scintigraphic lesion and ultimate scar formation in children with a first febrile urinary tract infection.
  Materials and Methods: A total of 89 girls and 138 boys with a first febrile urinary tract infection were included in the study. We analyzed radiological (ultrasound, dimercapto-succinic acid scintigraphy, voiding cystourethrogram), clinical (age, gender, peak fever, therapeutic delay time) and laboratory (complete blood count with differential count, absolute neutrophil count, blood urea nitrogen, creatinine, urinalysis, Gram’s stain, culture, C-reactive protein, erythrocyte sedimentation rate) variables. Dimercapto-succinic acid scintigraphy was performed within 5 days and at 6 months after diagnosis of urinary tract infection. Voiding cystourethrogram was performed after the acute phase of the urinary tract infection. Predictive factors for acute scintigraphic lesion and ultimate scar formation were assessed using logistic regression analysis.
  Results: Of 227 patients enrolled 140 had a refluxing and 87 a nonrefluxing urinary tract infection. On logistic regression analysis therapeutic delay time (p = 0.001) and presence of reflux (p = 0.011) were predictive of acute scintigraphic lesion and ultimate scar formation (p = 0.001 and p = 0.0001, respectively) in children with a first febrile urinary tract infection.
  Conclusions: Since vesicoureteral reflux is the common risk factor for acute scintigraphic lesion and ultimate scar formation, voiding cystourethrogram must be considered as an initial study in patients with acute febrile urinary tract infection.

• Editorial Comment
  This study examined 227 young children (mean age 9 months) who were hospitalized with their first febrile urinary tract infection. The authors were able to obtain a DMSA renal scan within 1 week of presentation and a subsequent scan at 5 to 7 months on all patients in the study. They also obtained laboratory values at the time of admission and reviewed VCUGs on all patients to determine reflux status. Multivariate logistic regression analysis demonstrated that both the presence of reflux and increased therapeutic delay time were predictive of an acute photon defect on the initial DMSA scan. They were also predictive of ultimate scar formation on follow-up DMSA scans, but the odds ratio was much higher for children with reflux (10.1 vs. 2.4).
  The patients in this study were a select population in that they were all young patients and all required hospitalization for their first urinary tract infection. The authors did a nice job getting a complete set of data on their entire study population, which is often a difficult task. The role of imaging studies after urinary tract infections has been challenged in recent years and this study reminds us that reflux status remains a significant risk factor for renal scarring, particularly in this young patient population.

M. Chad Wallis
Division of Pediatric Urology
University of Utah
Salt Lake City, Utah, USA
E-mail: chad.wallis@hsc.utah.edu