1. Department of Surgery, Atrium Medical Centre Parkstad, PO Box 4446, 6401 CX, Heerlen
2. Department of Surgery – Vascular Surgery, Catharina Hospital, PO Box 1350, 5602 ZA, Eindhoven
3. Department of Epidemiology, Caphri Research School, Maastricht University, PO Box 616, 6200 MD, Maastricht, The Netherlands