Renal outcome of children with horseshoe kidney: a single-center experience.

Objective: To assess the clinical features, additional abnormalities, and renal consequences of children with horseshoe kidney (HSK).

Methods: The medical records of 41 children with HSK followed in our pediatric nephrology clinic between the years of 2004 and 2014 were retrospectively reviewed.

Results: There were 22 girls (53.6%) and 19 boys (46.4%) aged 60 (2-192) months. The median follow-up time was 48 (12-120) months. HSK was incidentally found in 12 patients (29.3%), and 5 patients (12.2%) were prenatally diagnosed. Urinary tract abnormalities including vesicoureteral reflux (n = 8), ureteropelvic junction obstruction (n = 7), and duplex system (n = 3) were identified in 18 patients (43.9%). Eight children (19.5%) had bladder dysfunction, and 9 patients (21.9%) had additional systemic abnormalities. Urinary tract infection had been detected in 17 patients (41.4%). Seven patients (17%) required surgical intervention including pyeloplasty (n = 3), ureteroneocystostomy (n = 3), and upper pole heminephrectomy (n = 1). Renal scarring (RS) occurred in 10 patients (24.4%). Six patients (14.6%) developed proteinuria and 4 (9.8%) complicated with hypertension. Three patients (7.3%) progressed to chronic kidney disease (CKD). Multivariate logistic regression analysis showed that proteinuria, hypertension, and RS are independently associated with CKD.

Conclusion: Children with HSK might be examined for additional urologic and nonurologic abnormalities. Patients might be closely followed up for the increased risk of urinary tract infection and RS. Proteinuria, hypertension, and presence of RS seem to be the major determinants for progression to CKD in children with HSK.