1. Department of Plastic Surgery and Microsurgery, University Hospital of Cagliari, University of Cagliari, Monserrato, Italy
2. Department of Plastic Surgery, S. Orsola Hospital University of Bologna, Bologna, Italy
3. Unit of Clinical Epidemiology, Città della salute e della Scienza and CPO, Turin, Italy
4. Department of Medical Sciences and Public Health, University of Cagliari, Monserrato, Italy.