1. Department of Neurosurgery, First Affiliated Hospital of Harbin Medical University, Harbin 150001, China
2. Neurovascular Surgery Program, Department of Neurological Surgery, The University of Chicago, Chicago, IL 60637, USA
3. Department of Neurological Surgery, University of Chicago Medicine, 5841 S Maryland, MC3026/Neurosurgery J341, Chicago, IL 60637, USA