1 Paediatric Urology Service, San Borja Arriaran Hospital, University of Chile, Santiago, Chile; Department of Urology, School of Medicine, University of Chile, Santiago, Chile.
2 Paediatric Urology Service, Dr. Exequiel González Cortés Hospital, University of Chile, Santiago, Chile; Department of Pediatrics and Pediatric Surgery, School of Medicine, University of Chile, Santiago, Chile; Paediatric Urology Department, Clínica Alemana, Santiago, Chile.