1. Department of Pediatric Colorectal and Pelvic Reconstructive Surgery, Nationwide Children's Hospital Columbus, Ohio, United States
2. Colorectal and Urogenital Reconstruction Unit, La Paz University Hospital, Madrid, Spain
3. Department of Pathology, Son Espases University Hospital, Palma de Mallorca, Illes Balears, Spain
4. Department of Pathology, La Paz University Hospital, Madrid, Madrid, Spain
5. Department of Pathology, Vall d'Hebron Hospital Universitari, Barcelona, Catalunya, Spain
6. Department of Pediatric Surgery, Son Espases University Hospital, Palma de Mallorca, Illes Balears, Spain
7. Department of Pediatric Surgery, Hospital Universitario La Paz, Paseo de la Castellana 261, Madrid, Madrid, Spain
8. Division of General and Thoracic Surgery, SickKids, Toronto, Ontario, Canada
9. Division of Colorectal and Pelvic Reconstructive Surgery, Children's National Medical Center, Washington, District of Columbia, United States