Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome.

PURPOSE: Horseshoe kidney is the most common renal fusion anomaly. We determined the treatment and outcome of vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney. MATERIALS AND METHODS: We reviewed the medical and radiological records of 52 consecutive children, including 32 boys and 20 girls, in whom horseshoe kidney was diagnosed at 2 children's hospitals during 1990 to 1999. Patient age at diagnosis was 1 day to 12 years (mean 3.9 years). In 2 children with horseshoe kidney neuropathic bladder was secondary to spina bifida and they were excluded from study. The diagnosis was made in all cases by abdominal ultrasound and confirmed by excretory urography or (99m)technetium-dimercaptosuccinic acid scan. Voiding cystourethrography was performed in 40 cases (80%). Patients were followed for 2 to 11 years (mean 4.2). RESULTS: Associated urological anomalies were identified in 26 patients (52%) with horseshoe kidney, including primary vesicoureteral reflux in 13, ureteropelvic junction obstruction in 12 and ectopic ureter in 1. Surgical intervention to correct the anomalies in 15 of the 26 children (58%) involved pyeloplasty in 8, ureteral reimplantation in 2, endoscopic treatment for vesicoureteral reflux in 2, ureterolithotomy in 1, upper pole heminephrectomy in 1 and valve fulguration in 1. No significant complications were observed in surgically treated patients. CONCLUSIONS: More than half of the patients with a clinically symptomatic horseshoe kidney have vesicoureteral reflux or ureteropelvic junction obstruction. Many patients with horseshoe kidney require surgical intervention for associated urological anomalies with good results.