1. Center for Vein Restoration, Morrison Vein Institute, Scottsdale, AZ, USA
2. OhioHealth, Riverside Methodist Hospital, Columbus, USA
3. Venous Institute of Buffalo, Buffalo, USA
4. Medtronic Santa Rosa, Santa Rosa, USA
5. Inovia Vein Specialty Center, Bend, USA
6. Lake Washington Vascular, Bellevue, USA