1. Department of Vascular Surgery, St. Josef Hospital Bochum, Department of the Ruhr University Bochum, Germany
2. Vein Center of the Department of Dermatology and Department of Vascular Surgery, Katholisches Klinikum Bochum, Germany
3. Institute for Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Austria
4. Vein Center Capio Bad Betrich GmbH, Bad Bertrich, Germany
5. Department of Vascular Surgery, Krankenhaus Bethanien, Moers, Germany
6. Vein Center Capio Clinic im Park, Hilden, Germany
7. Gemeinschaftspraxis Saarlouis, Saarlouis, Germany
8. Department of Dermatology, St. Josef Hospital Bochum, Department of the Ruhr University Bochum, Germany