1. Department of Surgery University Hospital Kralovske Vinohrady Prague Czech Republic
2. Department of Anatomy, Second Faculty of Medicine Charles University Prague Czech Republic
3. Department of Surgery, Second Faculty of Medicine Charles University and Motol University Hospital Prague Czech Republic
4. Institute of Health Information and Statistics of the Czech Republic Prague Czech Republic
5. Institute of Biostatistics and Analyses, Faculty of Medicine Masaryk University Brno Czech Republic