[1] Univ Brescia, Dept Clin & Expt Sci, Surg Clin, I-25100 Brescia, Italy
[2] Univ Siena, Dept Human Pathol & Oncol, Surg Oncol, I-53010 Siena, Italy
[3] Univ Perugia, Dept Surg Sci Radiol & Dent, Div Gen Surg, I-06010 Perugia, Italy
[4] Univ Verona, Gen Surg, I-37010 Verona, Italy