Congenital renal anomalies in patients with classic bladder exstrophy

To determine the proportion and type of renal anomalies that occur in children born with classic bladder exstrophy. All patients in a database of 1044 patients with the bladder exstrophy-epispadias-cloacal exstrophy complex were reviewed. Those with classic bladder exstrophy had their complete medical records reviewed and children with radiographic evidence of congenital renal anomalies were identified and characterized. A total of 674 patients were identified with classic bladder exstrophy, of whom 462 had renal ultrasounds at the authors' institution. In this population, 13/462 (2.8%) had concomitant renal anomalies. The most common malformation was a duplicated collecting system in 6 patients. Hypoplastic or absent kidneys were present in 3 patients, pelvic kidney in 2, ureteropelvic junction obstruction in 1, and multicystic dysplastic kidney in 1 patient. Isolated renal anomalies occur at a rate of 2.8% in children born with classic bladder exstrophy. Although uncommon in this rare birth defect, anatomic understanding of the entire genitourinary system is critical for operative planning and long-term follow-up of patients with bladder exstrophy.