1. Department of General Surgery and Transplantation ASST Grande Ospedale Metropolitano Niguarda Milan Italy
2. Department of Surgical Sciences University of Pavia Pavia Italy
3. Department of Statistics and Quantitative Methods University of Milano‐Bicocca Milan Italy
4. Department of General Surgery IRCCS San Raffaele Scientific Institute Vita‐Salute University Milan Italy
5. Department of Medicine and Surgery University of Milano‐Bicocca Milan Italy