1General Surgery Dept., Papa Giovanni XXIII Hospital, Bergamo, Italy
2General Surgery Dept., Ospedale Maggiore, Parma, Italy
3General Surgery Dept., Centre Hospitalier Lyon Sud, Hospices Civils de Lyon and EMR 3738, Université Lyon 1, France
4General Surgery Dept., Kusatsu General Hospital, Yabase 1660, Japan
5Washington Cancer Institute, Washington, DC, USA
6Surgery Dept., University of Regensburg, Regensburg D-93053, Germany