1. From the Stroke Prevention Research Unit (R.B., P.M.R.), University Department of Clinical Neurology, Radcliffe Infirmary, Oxford, UK; the Vascular Group, Department of Surgery (K.R.), Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; the Department of Vascular and Endovascular Surgery (A.R.N.), Leicester Royal Infirmary, Leicester, UK; and the Department of Surgery (A.F.A.R.), Robert C. Byrd Health Sciences Center of West Virginia University, Charleston.