1. Department of Pediatric Surgery, Altona Children’s Hospital, Hamburg, Germany.
2. Department of Pediatric Surgery, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
3. Department of Pediatric Gastroenterology, Altona Children’s Hospital, Hamburg, Germany.
4. Department of Pathology, University Medical Center Hamburg Eppendorf, Hamburg, Germany.
5. Department of Pathology, University Hospital Basel, Basel, Switzerland.