Adam Whitley1,2, David Kachlik3. 1. Department of Surgery, University Hospital Kralovske Vinohrady, Šrobárova 1150/50, 100 34, Prague 10, Czech Republic. whitley.adam@gmail.com. 2. Department of Anatomy, Second Faculty of Medicine, Charles University, Prague, Czech Republic. whitley.adam@gmail.com. 3. Department of Anatomy, Second Faculty of Medicine, Charles University, Prague, Czech Republic.