1. From the Stroke Institute (R.L., S.Z., A.A., S.K., V.R., M.H., K.U., L.R.W., T.J.), Department of Neurosurgery (B.J., M.H.), University of Pittsburgh Medical Center, Pittsburgh, Pa; Department of Neurosurgery (A.T.), Beth Israel Deaconess Medical Center; Souers Stroke Institute (N.V.), Saint Louis University, Saint Louis, Mo; Cerebrovascular Center (R.G.), Cleveland Clinic, Ohio.