1. Gefässpraxis am See—Lakeside Vascular Center Lucerne, 6003 Lucerne, Switzerland
2. Department of Dermatology, Bern University Hospital Inselspital, University of Bern, 3012 Bern, Switzerland
3. Department of Angiology, University Hospital, University of Basel, 4001 Basel, Switzerland
4. Vascular Institute Central Switzerland, 5000 Aarau, Switzerland