ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP SCAI/SIR/SNIS/SVM/SVS Guideline 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/ SAIP/SCAI/SIR/SNIS/SVM/SVS Guideline on the Management of Patients With Extracranial Carotid and Vertebral Artery Disease: Executive Summary