1 Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany.
2 Department of Surgery, Clarunis-University Digestive Health Care Center, St. Clara Hospital and University Hospital Basel, Basel, Switzerland.
3 Department of General, Visceral and Transplantation Surgery, Heidelberg University Hospital, Heidelberg, Germany. beat.mueller@clarunis.ch.
4 Department of Surgery, Clarunis-University Digestive Health Care Center, St. Clara Hospital and University Hospital Basel, Basel, Switzerland. beat.mueller@clarunis.ch.