Basilar ArteryIntracranial AneurysmAneurysmArteriesVertebrobasilar InsufficiencyVertebral ArteryCerebral ArteriesAneurysm, InfectedCerebral AngiographySubarachnoid HemorrhageAortic AneurysmPulmonary ArteryTreatment OutcomeCarotid ArteriesBrain Stem InfarctionsEmbolization, TherapeuticAneurysm, DissectingRenal ArteryVasospasm, IntracranialFemoral ArteryAortic Aneurysm, ThoracicHeart AneurysmMesenteric ArteriesCarotid Artery, InternalTomography, X-Ray ComputedIliac ArteryVasodilationAngiography, Digital SubtractionVasoconstrictionIliac AneurysmCarotid Artery DiseasesMuscle, Smooth, VascularCoronary Artery BypassArterial Occlusive DiseasesBlood Vessel Prosthesis ImplantationSubclavian ArterySplenic ArteryAneurysm, FalseStentsRadial ArteryCoronary AneurysmMammary ArteriesCerebrovascular CirculationDogsAngiographyVasodilator AgentsFollow-Up StudiesMagnetic Resonance AngiographyRetrospective StudiesCircle of WillisMiddle Cerebral ArteryTime FactorsSerotoninEndovascular ProceduresBlood Vessel ProsthesisCeliac ArteryCarotid Artery, CommonAortic RuptureHepatic ArteryBrachial ArteryMesenteric Artery, SuperiorAorta, AbdominalCoronary VesselsPapaverinePotassium ChlorideVascular Surgical ProceduresRabbitsVasoconstrictor AgentsMuscle ContractionOphthalmic ArteryPicolinesPosterior Cerebral ArteryOutcome Assessment (Health Care)AortographyEndothelium, VascularSumatriptanIntracranial Embolism and ThrombosisPopliteal ArteryUltrasonography, Doppler, TranscranialProspective StudiesIschemic Attack, TransientAcetylcholineIntracranial ArteriosclerosisAneurysm, RupturedPostoperative ComplicationsDilatation, PathologicTemporal ArteriesRisk FactorsRenal Artery ObstructionIntracranial ThrombosisCerebral InfarctionThoracic ArteriesUmbilical ArteriesPonsBronchial ArteriesUlnar ArteryMechanical ThrombolysisCoronary AngiographyVasomotor SystemAnterior Cerebral Artery