[1] Northeast Ohio Med Univ, Coll Med, Rootstown, OH USA
[2] Northwestern Univ, Feinberg Sch Med, Chicago, IL 60611 USA
[3] Univ Vermont, Div Vasc Surg, Med Ctr, Burlington, VT USA
[4] Soc Vasc Surg Patient Safety Org, Analyt Div, Rosemont, PA USA
[5] Maine Med Ctr, Div Vasc & Endovasc Surg, Portland, ME 04102 USA
[6] Indiana Univ Sch Med, Div Vasc Surg, 1801 N Senate Blvd,D-3500, Indianapolis, IN 46202 USA