1. St Olavs Hospital; National Center for Advanced Laparoscopic Surgery (NSALK); Olav Kyrresgate 17 Trondheim Norway 7006
2. Medical Faculty of the Humboldt University at Berlin, Charité, Campus Mitte; Department of General-, Visceral-, Vascular- and Throacic Surgery; Schumannstrasse 20/21 Berlin Germany 10117
3. Helse Nord-Trøndelag Health Trust, Namsos Hospital; Department of General Surgery; Sykehusalleen 1 Namsos Norway 7800
4. Helse Nord-Trøndelag Health Trust, Namsos Hospital; Department of research and development; Sykehusalleen 1 Namsos Norway 7809
5. Erasmus Medical Center; Department of Surgery; PO Box 2040 Rotterdam Netherlands 3000 CA