Clinical Signif icance of Intrarenal Reflux in Children with Urinary Tract Infection

Lim, Beom Taek; Lee, Hae Sang; Pai, Ki Soo

Abstract

PURPOSE: Intrarenal reflux(IRR) is backflow of urine from the renal pelvis into the collecting ducts. IRR is the main cause of renal injury in children with vesicoureteral reflux (VUR) which leads to renal scars, hypertension, proteinuria, and chronic renal failure. The purpose of our study was to investigate the characteristics of intrarenal reflux.
METHODS
We retrospectively reviewed the medical records of 80 patients who were diagnosed as having grades of III-V VUR from Jan. 2004 to Dec. 2006 in the department of pediatrics in Ajou University Hospital. The patients were divided into two groups according to the presence of IRR on voiding cystoureterogram and compared to each other for the possible factors associated with intrarenal reflux.
RESULTS
Among 80 VUR patients, IRR(+) group comprised 17(21.3%) patients and 27 renal units(23.2%) and revealed younger age, higher grade of VUR, and more proteinuria compared to IRR(-) group. There were no significant difference in gender, laboratory findings and the rate of resolution in VUR or defects on renal scan between two groups. Also, intrarenal reflux mostly corresponded to the same site of photon defects on DMSA scan.
CONCLUSION
We suggest that intrarenal reflux tends to be associated with younger age, higher grade of reflux, more proteinuria with no difference in resolution rate of VUR when compared to the VUR patients without IRR. From this study, we were able to understand the characteristics of intrarenal reflux in children with urinary tract infection.