Affiliation: | 1. Division of Vascular and Endovascular Surgery, University of California, San Francisco, San Francisco, Calif;2. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, Calif;3. Division of Vascular and Endovascular Surgery, Brigham and Women''s Hospital, Boston, Mass;4. Division of Vascular Medicine, Brigham and Women''s Hospital, Boston, Mass |