1. University of Perugia; Department of General Surgery; Terni Italy 05100
2. Liver Unit and Department of Digestive Surgery, Hospital of Terni; Terni Italy
3. Chelsea and Westminster Hospital NHS Foundation Trust; General and Colorectal Surgery; 369 Fulham Road London UK SW10 9NH
4. Universidad de Antioquia; Department of General Surgery; Carrera 38 No 6 B Sur 25 Apto 1102 Medellín Antioquia Colombia 574