This clinical research study is designed to determine safety and effectiveness of the Surpass Flow Diverter (Surpass System), an investigational device developed to treat wide neck, large or giant intracranial aneurysms. An intracranial aneurysm is a bulge in the wall of a blood vessel in the brain. The bulge is caused by a weakening of the vessel wall. If left untreated, the bulge may continue to grow larger and ultimately the vessel may break open (rupture), resulting in serious bleeding into or around the brain. The information collected from this study will be used to evaluate how well patients do when treated with the Surpass System both immediately after treatment of an aneurysm and over a long period of time (5 years).