Deepveinthrombosis深静脉血栓

DeepveinthrombosisXiangYuChengWhatIsDeepVeinThrombosis?TheearliestcaseofDVTwasdescribedaround600-900BC.Atsomepoint,theincreasedincidenceofDVTinwomenafterchildbirthwasnoticed,andinthelate1700s,apublichealthrecommendationwasissuedtoencouragewomentobreastfeedasameanstopreventthisphenomenon;theDVTwascalledmilkleg,asitwasthoughttoresultfrommilkbuildingupintheleg.WhatIsDeepVeinThrombosis?Deepveinthrombosis,orDVT,isabloodclotthatformsinaveindeepinthebody.Bloodclotsoccurwhenbloodthickensandclumpstogether.WhatIsDeepVeinThrombosis?Abloodclotinadeepveincanbreakoffandtravelthroughtheblood.Theemboluscouldtraveltoanarteryinthelungsandblockbloodflow.Thisconditioniscalledpulmonaryembolism,orPE.EpidemiologyDeepveinthrombosis*DiagnosesofDVTandPEarenotmutuallyexclusive;anestimated78,511patientsreceiveddiagnosesofbothDVTandPE.VTEestimatesincludepatientswithdiagnosesofeitherDVTorPE.EpidemiologyDeepveinthrombosisAccordingtothemostrecentACCPguidelines,VTEremainsthesecondmostcommoncauseofprotractedhospitalstayandthethirdmostcommoncauseofexcessmortalityamong7millionpatientsdischargedfrom944acutecarehospitalsintheUS.CausesGermanpathologistRudolfVirchowpostulatedtheinterplayofthreeprocessesresultinginvenousthrombosis,nowknownasVirchow'striad:DeepveinthrombosisInkeepingwithVirchow'sconcept,alterationsofthecoagulationsystemthatinduceahypercoagulablestatealsoconferanincreasedriskofDVT.CausesGermanpathologistRudolfVirchowpostulatedtheinterplayofthreeprocessesresultinginvenousthrombosis,nowknownasVirchow'striad:DeepveinthrombosisCausesThebloodflowpatterninthevalvescancausehypoxemia,whichisworsenedbyvenousstasis,activatespathways-onesthatincludehypoxia-induciblefactor-1andearly-growth-responseprotein1.Hypoxia-induciblefactor-1andearly-growth-responseprotein1contributetomonocyteassociationwithendothelialproteins,suchasP-selectin,promptingmonocytestoreleasetissuefactor-filledmicrovesicles,whichpresumablybeginclottingafterbindingtotheendothelialsurface.[9]DeepveinthrombosisCausesIndependentRiskFactorsforDVTAgeisanindependentriskfactorforthromboticdisease.Themajorityofvenousthrombioccurineitherthesuperficialordeepveinsoftheleg.ADVTisstationaryclottingbloodadheredtothedeepveinofthepelvisoranextremityandusuallyoccursinthecalforthigh.VTEdenotesanobstructionarisingfromtheformationofaclotinthevenouscirculationcarriedbythebloodfromthesiteoforigintopluganothervessel.DeepveinthrombosisCausesIndependentRiskFactorsforDVTDeepveinthrombosisSignsandsymptomsCommonsignsandsymptomsofDVTinclude：√Pain…√Swelling…√Warmth…√Rednessordiscoloration…√Distentionofsurfaceveins…DeepveinthrombosisSignsandsymptomsCommonsignsandsymptomsofDVTinclude：√Pain…√Swelling…√Warmth…√Rednessordiscoloration…√Distentionofsurfaceveins…DeepveinthrombosisSignsandsymptomsInmostsuspectedcases,DVTisruledoutafterevaluation,andsymptomsaremoreoftenduetoothercauses,suchascellulitis,Baker'scyst,musculoskeletalinjury,orlymphedema.Otherdifferentialdiagnosesincludehematoma,tumors,venousorarterialaneurysms,andconnectivetissuedisorders.DeepveinthrombosisDiagnosisProbability:InthosewithsuspectedDVT,aclinicalassessmentofprobabilitycanbeusefultodeterminewhichteststoperform.ThemoststudiedclinicalpredictionruleistheWellsscore.DeepveinthrombosisDiagnosisDeepveinthrombosisDiagnosisPhysicalExam:symptomsHalfofthosewiththeconditionHAVENOSYMPTOMS.Signsandsymptomsalonearenotsufficientlysensitiveorspecifictomakeadiagnosis,butwhenconsideredinconjunctionwithknownriskfactorscanhelpdeterminethelikelihoodofDVT.DeepveinthrombosisDiagnosisDVTdiagnosisrequirestheuseofimagingdevicessuchasultrasound.Clinicalassessments,whichpredictDVTlikelihood,canhelpdetermineifaD-dimertestisuseful.InthosenothighlylikelytohaveDVT,anormalD-dimerresultcanruleoutadiagnosis.DeepveinthrombosisDiagnosisD-dimer:Afibrindegradationproduct,andanelevatedlevelcanresultfromplasmindissolvingaclot,orotherconditions.DeepveinthrombosisDiagnosisForthosewithalowormoderateprobabilityofDVT,aD-dimerlevelmightbeobtained,whichexcludesadiagnosisifresultsarenormal.Anelevatedlevelrequiresfurtherinvestigationwithdiagnosticimagingtoconfirmorexcludethediagnosis.DeepveinthrombosisDiagnosisForasuspectedfirstlegDVTinalow-probabilitysituation,theAmericanCollegeofChestPhysicians(ACCP)recommendstestingeitherD-dimerlevelswithmoderateorhighsensitivityorcompressionultrasoundoftheproximalveins.DeepveinthrombosisDiagnosisImaging:ImagingtestsoftheveinsareusedinthediagnosisofDVT.Ultrasound,CTscanvenography,MRIvenography,orMRIofthethrombusarealsopossibilities.DeepveinthrombosisDiagnosisUltrasound:asensitiveandspecifictoolfortheassessmentofpatientspresentingwithsymptomssuggestiveoflowerextremityDVT.DeepveinthrombosisDiagnosisDoplerUltrasoundDeepveinthrombosisDiagnosisContrastVenography:Thegoldstandardmethodstorevealwhetherthevenoussupplyhasbeenobstructed.Deepveinthrombosis(a)directmanualcontrastinjectionintotheguidingcatheter(directvenographytechnique,DVT)and(b)occlusionofcoronarysinusbyaSwan-Ganzcatheter.DiagnosisContrastVenography:Thegoldstandardmethod