1. Department of Pediatric Surgery, Hannover Medical School, Hannover, Niedersachsen, Germany
2. Department of Pediatric Surgery, The Queen Silvia Children’s Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
3. Department of Pediatrics, Institute of Clinical Sciences, University of Gothenburg, Gothenburg, Sweden
4. Department of Medical Psychology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany