Mesenteric VeinsHepatic ArteryMesenteric Vascular OcclusionPortal VeinMesenteric ArteriesMesenteric Artery, SuperiorSplenic VeinPortal SystemArteriesPancreaticoduodenectomyHepatic VeinsSplanchnic CirculationIliac VeinMesenteric Artery, InferiorHypertension, PortalVeinsTomography, X-Ray ComputedVenous ThrombosisVena Cava, InferiorThrombosisCeliac ArteryLiver CirculationGastrointestinal HemorrhagePulmonary ArteryPancreatic NeoplasmsTreatment OutcomeRenal ArterySplenic ArteryCarotid ArteriesCerebral ArteriesFemoral ArteryMuscle, Smooth, VascularRenal VeinsBasilar ArteryVasoconstrictionNorepinephrineSaphenous VeinLiverFemoral VeinAngiographyLiver TransplantationSuperior Mesenteric Artery SyndromeHemobiliaIliac ArteryVasodilationAneurysmInfusions, Intra-ArterialDogsVertebral ArteryCoronary Artery BypassVisceraEmbolization, TherapeuticTime FactorsRadial ArteryMammary ArteriesAnastomosis, SurgicalBiological FactorsAneurysm, FalseRegional Blood FlowCarotid Artery, InternalVascular Surgical ProceduresSubclavian ArteryEndothelium, VascularRats, Sprague-DawleyArterial Occlusive DiseasesVaricose VeinsLigationVasodilator AgentsLiver NeoplasmsCarotid Artery DiseasesVasoconstrictor AgentsVena Cava, SuperiorBrachial ArteryDose-Response Relationship, DrugConstriction, PathologicPulmonary VeinsRats, WistarMuscle ContractionCoronary VesselsRabbitsSuperior ColliculiRetrospective StudiesCarotid Artery, CommonUltrasonography, DopplerInjections, Intra-ArterialAcetylcholineIofetamineOphthalmic ArteryIschemiaJugular VeinsPostoperative Complications