1. Maastricht University Medical Centre, Department
of Surgery, PO Box 5800, 6202
AZ Maastricht, The Netherlands.
2. Canisius Wilhelmina Hospital, Department
of Surgery, PO Box 9015, 6500
GS Nijmegen, The Netherlands.
3. Rijnstate hospital Arnhem, Department
of Surgery, PO Box 9555, 6800
TA Arnhem, The Netherlands.