1 Department of Gastrointestinal Surgery, Østfold Hospital Trust, Grålum, Norway, Institute for Clinical Medicine, University of Oslo, Oslo, Norway.
2 Department of Gastrointestinal Surgery, Østfold Hospital Trust, Grålum, Norway, Institute for Clinical Medicine, University of Oslo, Oslo, Norway, Interventional Centre, Oslo University Hospital-Rikshospitalet, Oslo, Norway, Department of Surgery, Fonna Hospital Trust, Odda, Norway, Department of Faculty Surgery N 2, I.M. Sechenov First Moscow State Medical University, Moscow, Russia, Department of Surgery N 2, Yerevan State Medical University After M. Heratsi, Yerevan, Armenia.
3 Anatomy Sector, Teaching Unit, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
4 Institute for Clinical Medicine, University of Oslo, Oslo, Norway, Department of Digestive Surgery, Akershus University Hospital, Lørenskog, Norway.