Mesenteric VeinsPortal VeinMesenteric Vascular OcclusionVeinsPortal SystemSplenic VeinFemoral VeinRenal VeinsSaphenous VeinIliac VeinSplanchnic CirculationIdiopathic Pulmonary FibrosisVaricose VeinsVenous ThrombosisHepatic VeinsVisceraPulmonary VeinsVena Cava, InferiorHypertension, PortalPancreaticoduodenectomyIofetamineJugular VeinsNorepinephrineMesenteric ArteriesLiver CirculationPortasystemic Shunt, SurgicalMesenteric Artery, SuperiorAdrenergic alpha-2 Receptor AntagonistsEsophageal and Gastric VaricesAmphetaminesThrombosisTomography, X-Ray ComputedScoliosisMuscle, Smooth, VascularDogsArthritis, JuvenileUmbilical VeinsBudd-Chiari SyndromePurpura, Thrombocytopenic, IdiopathicAnastomosis, SurgicalGastrointestinal Hemorrhage