1. From the Division of Vascular and Interventional Radiology, Mayo Clinic Arizona, 5777 E Mayo Blvd, Phoenix, AZ (K.S.Z., S.O.S., S.J.A., I.J.P., S.G.N., R.O., M.G.K.); Minimally Invasive Procedure Specialists, Highlands Ranch, Colo (E.B.S., A.L.); and University of Illinois College of Medicine at Chicago, Chicago, IL (R.A.D.).