1 Department of Surgery, Zuyderland Medical Center Sittard-Geleen, PO Box 5500, 6130 MB Sittard-Geleen, The Netherlands. Electronic address: claireleenarts@hotmail.com.
2 Department of Surgery, Zuyderland Medical Center Heerlen, PO Box 5500, 6130 MB Sittard, The Netherlands.