1 Department of Gastroenterology & Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam 1100 DD, Netherlands.
2 Department of Surgery, St Antonius Hospital, Nieuwegein, Netherlands; Department of Surgery, University Medical Centre Utrecht, Utrecht, Netherlands.
3 Department of Surgery, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC, University of Amsterdam, Amsterdam 1100 DD, Netherlands. Electronic address: m.g.besselink@amsterdamumc.nl.