[1] Univ Hosp Maastricht, Dept Surg, NL-6202 AZ Maastricht, Netherlands
[2] CHU Estaing, Dept Gen & Digest Surg, Clermont Ferrand, France
[3] Univ Hosp Northern Norway, Dept Gastrointestinal Surg, Tromso, Norway
[4] Univ Tromso, Inst Clin Med, Tromso, Norway
[5] Royal Infirm, Edinburgh, Midlothian, Scotland
[6] Maastricht Univ, Med Ctr, NUTRIM Sch Nutr Toxicol & Metab, Maastricht, Netherlands