[1] St Maria Hosp, Dept Digest, I-05100 Terni, Italy
[2] St Maria Hosp, Liver Surg Unit, I-05100 Terni, Italy
[3] Univ Perugia, St Maria Hosp, I-05100 Terni, Italy
[4] Univ Perugia, Dept Gen & Oncol Surg, I-06157 Perugia, Italy
[5] Univ Roma La Sapienza, Dept Gen Surg, I-00161 Rome, Italy