Open, prospective, controlled randomized superiority trial is conducted. The hypothesis is that endovascular flow-diversion is better than revascularization in treatment of complex intracranial aneurysms by postoperative modified Rankin Scale (mRS). Sample size was measured by Fisher exact test. Depending on a type of the procedure, the patients are divided into two groups: Endovascular Flow Diversion Procedure (include 55 patients) and Revascularization Procedure (include 55 patients). Randomization is performed by random number generation.The study was approved by Institutional Review Board