1. Division of Cardiology, Rocky Mountain Regional VA Medical Center, University of Colorado, Aurora, CO, USA
2. Anschutz Medical Center, Division of Vascular Surgery and Endovascular Therapy, University of Colorado, Aurora, CO, USA
3. Division of Vascular Surgery, Sao Paulo State University, Botucatu School of Medicine, Botucatu, Brazil
4. Division of Vascular Surgery, University of California San Francisco, Fresno, CA, USA
5. Division of Vascular Surgery, Federal University of Maranhao, Sao Luiz, Brazil