1. Department of Vascular Surgery and Organ Transplant Unit, University Hospital of Catania, Catania, Italy
2. 3rd Department of Vascular Surgery, Athens Medical Center, Athens, Greece
3. Clinic of Vascular Surgery, Marien Hospital Herne, Ruhr-University of Bochum, Herne, Germany
4. Advanced Cardiac and Vascular Centers for Amputation Prevention, Grand Rapids, MI, USA
5. St. Franziskus-Hospital, Muenster, Germany
6. Department of Vascular Surgery, Ludwig-Maximilians-University Hospital, Munich, Germany