[1] Sisters of Charity Hospital,Department of General and Visceral Surgery
[2] Academic Teaching Hospital of the Universities of Graz,Center for Minimally Invasive Surgery
[3] Academic Teaching Hospital of the Universities of Innsbruck,Department of Surgery
[4] Hospital Neuwerk,Department of General, Visceral and Transplantation Surgery
[5] Paracelsus Medical University,undefined
[6] RWTH Aachen University,undefined