1. Department of Visceral and Transplantation Surgery, University of Berne, Inselspital, Berne, Switzerland
2. Department of Surgery, University of Ulm, Sandoz AG, Nürnberg, Germany
3. Department of Surgery, University of Münster, Sandoz AG, Nürnberg, Germany
4. Department of Surgery, University of Düsseldorf, Sandoz AG, Nürnberg, Germany
5. Department of Surgery, Clinical Research Department, Sandoz AG, Nürnberg, Germany