1. Department of Surgery, Isala hospital, Zwolle, The Netherlands
2. Department of Surgery, University Medical Centre Groningen, Groningen, the Netherlands
3. Department of Surgery, Amsterdam University Medical Centres, University of Amsterdam, Cancer Centre Amsterdam, Amsterdam, the Netherlands
4. Department of Gastroenterology and Hepatology, Amsterdam University Medical Centres, Amsterdam, the Netherlands
5. Department of Surgery, Meander hospital, Amersfoort, the Netherlands
6. Department of Surgical Oncology and Gastrointestinal Surgery, Erasmus Medical Centre, Rotterdam, the Netherlands