1. University Hospital Freiburg, Department of General and Digestive Surgery – University of Freiburg, Faculty of Medicine, Freiburg, Germany.
2. University Hospital Freiburg, Department of Pediatric and Adolescent Medicine – University of Freiburg, Faculty of Medicine, Freiburg, Germany.
3. Department of Surgery, University Medical Center Schleswig-Holstein, Campus Luebeck, Germany
4. University Hospital Freiburg, Department of Medicine II – University of Freiburg, Faculty of Medicine, Freiburg, Germany.