Background　Stent　placement　has　been　widely　used　to　assist　coiling　in　cerebral　aneurysm　treatments.　The　present　study　aimed　to　investigate　the　hemodynamic　effects　of　stenting　on　wide-necked　intracranial　aneurysms.　Methods　Three　idealized　plexiglass　aneurismal　models　with　different　geometries　before　and　after　stenting　were　created,　and　their　three-dimensional　computational　models　were　constructed.　Flow　dynamics　in　stented　and　unstented　aneurismal　models　were　studied　using　in　vitro　flow　visualization　and　computational　fluid　dynamics　(CFD)　simulations.　In　addition,　effects　of　stenting　on　flow　dynamics　in　a　patient-specific　aneurysm　model　were　also　analyzed　by　CFD.　Results　The　results　of　flow　visualization　were　consistent　with　those　obtained　with　CFD　simulations.　Stent　deployment　reduced　vortex　inside　the　aneurysm　and　its　impact　on　the　aneurysm　sac,　and　decreased　wall　shear　stress　on　the　sac.　Different　aneurysm　geometries　dictated　fundamentally　different　hemodynamic　patterns　and　outcomes　of　stenting.　Conclusions　Stenting　across　the　neck　of　aneurysms　improves　local　blood　flow　profiles.　This　may　facilitate　thrombus　formation　in　aneurysms　and　decrease　the　chance　of　recanalization.　Chin　Med　J　2010;123(15):1999-2003