[1] Burgerspital, Dept Surg, Solothurn, Switzerland
[2] Kepler Univ Hosp, Inst Pathol & Mol Pathol, Linz, Austria
[3] Johannes Kepler Univ Linz, Linz, Austria
[4] Clarunis Univ Ctr Gastrointestinal & Liver Dis, St Clara Hosp Basel, Basel, Switzerland
[5] Univ Hosp Basel, Basel, Switzerland
[6] Hosp Thun, Dept Surg, Thun, Switzerland