1. Department of Surgery, Dr Josef Trueta Hospital, Gerona, Mataró, Spain
2. Department of Surgery, Germans Trias y Pujol Hospital, Badalona, Mataró, Spain
3. Department of Surgery, Bellvitge Hospital, Barcelona, Mataró, Spain
4. Department of Surgery, Parc Tauli Hospital Consortium, Sabadell, Mataró, Spain
5. Department of Surgery, Sta Creu i St Pau Hospital, Barcelona, Mataró, Spain
6. Department of Surgery, San Jaume i Sta Magdalena Hospital, Mataró, Spain