Factors associated with renal scarring in children with vesicoureteral reflux

Introduction: Vesicoureteral reflux (VUR), a prevalent urological disorder in pediatrics, often leads to severe consequences such as renal scarring, hypertension, and end-stage renal diseases. Objectives: This study investigates the prevalence of renal scarring and its potential predisposing factors in children with VUR. Patients and Methods: A prospective cross-sectional study was conducted at a pediatric tertiary referral hospital between 2014 and 2017. Patients diagnosed with VUR underwent TC99m-DMSA scans. The presence of a renal cortical uptake defect on the renal scan was indicative of renal scarring. In cases with a history of pyelonephritis, the persistence of renal cortical defects for ≥12 months following acute pyelonephritis was defined as renal scarring. Results: A total of 93 patients were enrolled, comprising 62 girls (66.7%) and 31 boys (33.3%). The age of the initial visit to the nephrology clinic was 44.29 ± 43.38 months. Tc-99m DMSA scans identified renal scarring in 28 out of 93 (30.1%) patients and 41 out of 186 (22.04%) kidney ureter units (KUUs), encompassing 32 out of 111 (28.8%) refluxing and 9 out of 75 (12%) non-refluxing kidney units. Renal scarring was observed in 6 out of 21 (28.6%) cases with no history of urinary tract infection (UTI), 13 out of 57 (22.8%) cases with a history of pyelonephritis, and 9 out of 15 (60%) cases with a history of cystitis (P=0.02). Patients with renal scarring were diagnosed with VUR at an older age than those without scarring (45.38±37.37 versus 22.21±22.45 months, respectively; P=0.0001). The prevalence of renal scarring was 21.55% among cases seen in the nephrology clinic at or before the age of 5 years, whereas it was 50% among those referred after the age of 5 years (P=0.006). The diagnosis of VUR after age five years was significantly associated with renal scarring (61.5% versus 25%, respectively) (P= 0.003). No significant associations were found between high-grade and mild-to-moderate VUR or between primary and secondary VUR with renal scarring (P>0.05 for both). Conclusion: Renal scarring is prevalent in the VUR population, occurring as frequently in cases with a history of pyelonephritis as in those without. Early detection of VUR can potentially delay the development of renal scarring.