[1] Maggiore Hosp, Reg Emergency Surg & Trauma Ctr, Bologna Local Hlth Dist, Emergency Surg & Trauma Surg Unit,AUSL, Bologna, Italy
[2] Univ Parma, Maggiore Hosp Parma, Emergency Surg Dept, I-43100 Parma, Italy
[3] John Paul II Mem Hosp, Dept Gen Surg, Belchatow, Poland
[4] Univ Perugia, Gen & Emergency Surg Dept, Terni Hosp, I-06100 Perugia, Italy