Plasma rennin activity: Early indicator of renal injury in bilateral pelviureteric junction obstruction in children

OBJECTIVE: The objective of the present study is to analyze the early indicators of renal injury in children with bilateral pelviuretric junction obstruction. MATERIALS AND METHODS: We investigated 23 children, 46 kidney units who were diagnosed with bilateral pelvi-ureteric junction obstruction (PUJO) and underwent unilateral or bilateral pyeloplasty between January 2001 and December 2011. Ipsilateral kidney biopsy was performed during pyeloplasty. Kidney biopsy results were divided into three categories. Pre-operative investigation included ultrasonography with the Society of Fetal Urology (SFU) grading, plasma rennin activity (PRA) and differential renal function (DRF). RESULTS: Out of 23 children there were 17 (73.9%) boys while 6 (26.1%) girls. Median age at operation was 35.4 months (range: 9-60 months). Unilateral pyeloplasty was performed in 14 (60.8%), simultaneous bilateral pyeloplasty in 2 (8.6%) and sequential bilateral pyeloplasty in 7 (30.4%). CONCLUSION: In bilateral PUJO where DRF and SFU grading of hydronephrosis did not correctly reflect renal injury, PRA showed a significant relationship with renal histopathologic grade and could be an early indicator of renal injury in bilateral PUJO.