1. Institute of Clinical Physiology, National Research Council, Pisa, Italy
2. Division of Hepatic Surgery and Liver Transplantation, University of Pisa Medical School Hospital, Pisa, Italy
3. Tuscany Regional Transplant Authority, Centro Regionale Allocazione Organi e Tessuti (CRAOT), Florence, Italy.
4. Department of Anesthesia and Critical Care Medicine, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
5. Division of Medical Statistics, University of Pisa Medical School Hospital, Pisa, Italy