1 Herniacenter Dr. Muschaweck - Dr. Conze, Arabellastr. 17, 81925, Munich, Germany. jc@hernien.de.
2 Department of General, Visceral and Transplantation Surgery, RWTH Aachen, University Hospital, Pauwelsstr. 30, 52074, Aachen, Germany. jc@hernien.de.