AspirinVenous ThrombosisVeinsThrombophlebitisFemoral VeinSaphenous VeinPopliteal VeinIliac VeinVaricose VeinsPulmonary EmbolismPhlebographyPortal VeinAnticoagulantsUpper Extremity Deep Vein ThrombosisPulmonary VeinsLegJugular VeinsPlatelet Aggregation InhibitorsVenous InsufficiencyFibrin Fibrinogen Degradation ProductsUltrasonography, Doppler, DuplexHeparin, Low-Molecular-WeightAnti-Inflammatory Agents, Non-SteroidalVena Cava, InferiorMesenteric VeinsVenous ThromboembolismRenal VeinsUmbilical VeinsWarfarinIntermittent Pneumatic Compression DevicesPostphlebitic SyndromeHeparinStockings, CompressionPlethysmography, ImpedanceVena Cava FiltersFibrinolytic AgentsHepatic VeinsBandagesTreatment OutcomeHemorrhageLower ExtremityThromboembolismProspective StudiesTime FactorsVaricose UlcerPostoperative ComplicationsRisk FactorsSubclavian VeinVenous ValvesThrombosisCerebral VeinsTiclopidineSplenic VeinThromboxane B2Follow-Up StudiesCyclooxygenase InhibitorsDeep Brain StimulationRecurrencePlatelet AggregationThrombophiliaRetinal VeinCatheterization, PeripheralBrachiocephalic VeinsSalicylatesRetrospective StudiesAzygos VeinGravity SuitsUltrasonography, Doppler, ColorThrombectomyEnoxaparinThrombolytic TherapyUltrasonography, DopplerFactor VPlatelet Function TestsPregnancy Complications, CardiovascularVascular PatencyRetinal Vein OcclusionDrug Therapy, CombinationAxillary VeinVascular Surgical ProceduresRisk AssessmentPopliteal CystNadroparinVenous PressureIncidenceFibrinogenPlethysmographyBlood PlateletsDalteparinKlippel-Trenaunay-Weber SyndromeThighSclerotherapyActivated Protein C ResistanceFasciaDose-Response Relationship, DrugVascular MalformationsSodium SalicylateDoppler EffectCatheterization, Central VenousAntifibrinolytic Agents