1. Department of Surgery, Leiden University Medical Centre, Leiden, The Netherlands
2. Department of Surgery, Alrijne Hospital, Leiderdorp, The Netherlands
3. Department of Surgery, Medical Centre Haaglanden, The Hague, The Netherlands
4. Department of Surgery, Meander Medisch Centrum, Amersfoort, The Netherlands
5. Department of Surgery, Medical Centre Haaglanden, The Hague
6. Department of Surgery, Groene Hart Hospital, Gouda
7. Department of Surgery, Alrijne Hospital, Leiderdorp
8. Department of Surgery, Haga Hospital, The Hague
9. Department of Surgery, Bronovo Hospital, The Hague
10. Department of Surgery, Reinier de Graaf Group, Delft
11. Department of Surgery, Maasstad Hospital, Rotterdam
12. Department of Surgery, Amphia Hospital, Breda
13. Department of Surgery, Sint Antonius Hospital, Nieuwegein
14. Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam