胰腺疾病的诊治课件

APPROACHTOTHEPATIENTWITHPANCREATICDISEASEAPPROACHTOTHEPATIENTWITHP1GENERALCONSIDERATIONSInflammatorydiseaseofpancreas:acute/chronic.acutepancreatitis:frequency:5000/newcases/yrUSAmortalityrate:10%recurrentacutepancreatitisorchronicpancreatitis:Incidence:8.2newcases/100,000/yearprevalence:26.4cases/100,000.prevalenceofchronicpancreatitis(autopsy):0.045%.GENERALCONSIDERATIONSInflam2PANCREATITIS:DEFINITIONAcutepancreatitisAbdominalpainUsuallyassociatedwithelevatedlevelsofpancreaticenzymesinbloodorurineresultingfromaninflammatorypancreaticdiseaseChronicpancreatitisIrreversiblemorphologicchange,sclerosisPainPermanentimpairmentoforgansfunctionPANCREATITIS:DEFINITION3ProblemsinDxofPancreaticDiseaserelativeinaccessibilitytodirectexaminationandnonspecificityoftheabdominalpainusuallydependentonelevationofbloodamylase.Manypatientswithchronicpancreatitisdonothaveelevatedbloodamylaselevels.subclinicalexocrinedysfunction(90%ofpancreasbedamaged.secretinstimulationtest(themostsensitivemethodofassessingpancreaticexocrinefunction):60%ofexocrinefunctionlost.Noninvasive,indirecttests(bentiromide,trypsinogen):inobvious(calcification,steatorrhea,DM)thanoccultdisease.ProblemsinDxofPancreaticD4clinicalmanifestationsclinicalmanifestations:Proteanhypertriglyceridemia,vit-B12malabsorption,hypercalcemia,hypocalcemia,hyperglycemia,ascites,pleuraleffusions,andchronicabdominalpainwithnormalbloodamylase.ifconsiderspancreatitisonlyclassicsymptoms(i.e.,severe,constantepigastricpainthatradiatesthroughtotheback,alongwithanelevatedbloodamylaselevel):onlyaminorityofpatientswillbediagnosedcorrectly.Etiologies:quitevaried.frequentlysecondarytoalcoholabuseandbiliarytractdiseasedrugs,trauma,virus,metabolic&connectivetissuedisorders.Idiopathicpancreatitis:30%(acute),2540%(chronic)clinicalmanifestationsclinica5TESTSINTHEDIAGNOSISOFPANCREATICDISEASEpancreaticfunctiontestsareperformedifthediagnosisofpancreaticdiseaseremainsapossibilityafternoninvasivetestsUS,CTandinvasivetestsERCPhavegivennormalorinconclusiveresults.testsemployingdirectstimulationofthepancreasarethemostsensitive.TESTSINTHEDIAGNOSISOFPANC6PANCREATICENZYMESINBODYFLUIDSserumamylase:ascreeningtestforacutepancreatitisinacuteabdominalpainorbackpain.65U/L:raisethequestionofacutepancreatitis.130U/L:makethediagnosismorelikely,3x:clinchtheDxifgutperforation/infarctionisexcluded.acutepancreatitis:85%ofpatientswithwillhaveanserumamylase.serumamylase:within24hofonset,remains13days.returntonormalwithin35daysunlessextensivenecrosis,incompleteductalobstruction,pseudocystformation.maybenormal,if:(1)delay(of25days)beforebloodsamplesareobtained(2)chronicpancreatitisratherthanacutepancreatitis(3)hypertriglyceridemia.spuriouslylowamylase,lipase.PANCREATICENZYMESINBODYFLU7serumamylaseelevatedinotherconditions:theenzymeisfoundinmanyorgans(salivaryglands,liver,smallintestine,kidney,fallopiantube)producedbytumors(Caoflung,esophagus,breast,ovary).Isoenzymesofamylase:pancreas(Pisoamylases);nonpancreaticsource(Sisoamylases).normalserum:3545%isofpancreaticorigin.Theclinicalimportanceinmeasurementofisoamylases.acutepancreatitis:totalserumamylasereturnstonormalmorerapidlythanpancreaticisoamylase.postoperativestate,acutealcoholintoxication,andDKA:duetoanelevationoftheSisoamylase.teststodistinguishisoamylase:notreliablewhenthetotalamylaseisminimallymoderatelyelevated.assayoftrypsinogen:ifnormalr/oacutepancreatitis.Urinaryamylase,amylase/creatinineclearanceratio:nomoresensitive/specificserumamylaseelevatedinothe8asciticfluidamylaseacutepancreatitis(1)pancreatogenousascites:disruptionofthemainPDofaleakingpseudocyst(2)otherabdominaldisordersthatsimulatepancreatitisintestinalobstruction,intestinalinfarction,PPUElevationofpleuralfluidamylaseacutepancreatitis,chronicpancreatitis,carcinomaofthelung,andesophagealperforation.asciticfluidamylaseacutepan9Lipase:thesinglebestenzymefortheDxofacutepancreatitis.Improvementsinsubstratesandtechnology(turbidometricassay).newerlipaseassays:colipaseasacofactorandarefullyautomated.Lipase:10assayfortrypsinogen(trypsin-likeimmunoreactivity)useful&theoreticaladvantageoveramylaseandlipase.Sensitivity,specificity:C/Wthoseofamylaseandlipase.trypsinogenisalsoexcretedbythekidney:inrenalfailureNosinglebloodtestisreliablefortheDxofacutepancreatitisinrenalfailure.whetherapatientwithESRDandabdominalpainhaspancreatitisremainsadifficultclinicalproblem.serumamylaseinpatientswithrenaldysfunctiononlywhenCCr50mL/min.levelwasinvariably3xnormalarehighlyspecific.sensitivity&specificityof512STUDIESPERTAININGTOPANCREATICSTRUCTURERadiologicTestsPlainfilmsofabdomen:usefulinformationin3050%ofacutepancreatitis.(1)localizedileus:usuallythejejunum(sentinelloop),(2)generalizedileus+air-fluidlevels(3)isolateddistentionoftransversecoloncoloncutoffsign,(4)duodenaldistentionwithair-fluidlevels(5)mass(frequentlyapseudocyst).chronicpancreatitis:pancreaticcalcificationcharacteristicallylocalizedadjacenttoandsuperimposedonthesecondlumbarvertebraSTUDIESPERTAININGTOPANCREAT13Upper gastrointestinal x-raysdisplacementofstomachbytheretroperitonealmasswideningandeffacementoftheduodenalCloop(also,pancreaticmass,inflammatory,cystic,orneoplastic).Ultrasonographyinitialinvestigationforpancreaticdisease.Interference:obesity,excessbowelgas,recentlyperformedbariumcontrastexaminationsappearances:edema,inflammation,calcificationpseudocyst,masslesions,andgallstonesacutepancreatitis:characteristicallyenlargedpancreas.Pseudocyst:echo-free,smooth,roundfluidcollection.Pancreaticcarcinoma:distortstheusuallandmarksmasslesions3.0cm:localized,echo-freesolidlesions.Uppergastrointestinalx-rays14thebestimagingstudyforinitialevaluationespeciallyuseful:tumors,fluid-containinglesions(seudocysts,abscesses,calciumdeposits)Mostlesionsarecharacterizedby(1)enlargementofthepancreaticoutline(2)distortionofthepancreaticcontour(3)afluidfillingthathasadifferentattenuationcoefficientthannormalpancreas.CTthebestimagingstudyforini15occasionallydifficulttodistinguishbetweeninflammatoryandneoplasticlesions.Oralwater-solublecontrastagentspermitsmoreprecisedelineationofvariousorgansaswellasmasslesions.DynamicCT:estimatingthedegreeofpancreaticnecrosisandinpredictingmorbidityandmortality.Spiral(helical)CT:clearimagesmuchmorerapidlynegatesartifactcausedbypatientmovementoccasionallydifficulttodist16Selective catheterizationceliac&SMA+superselectiveothersarteriesvisualizationofthepancreasanddetectionofneoplasmsandpseudocysts.Pancreaticneoplasms:identifiedbythesheathingofvesselsbyamasslesionHormone-producingpancreatictumors:especiallyincreasedvascularityandtumorstaining.inpancreaticcarcinoma,uncommonwithoutpancreaticdiseaseAngiographycomplementsultrasonographyandERCP:ifERCPisunsuccessfulornondiagnostic.magnetic resonance cholangiopancreatography(MRCP):tobeofvalueSelectivecatheterizationcel17ERCPPancreaticcarcinoma:stenosis/obstructionofeitherthePDorCBD;bothductalsystemsareoftenabnormal.chronicpancreatitis:(1)luminalnarrowing(2)irregularitiesintheductalsystemwithstenosis,dilation,sacculation,andectasia(3)blockageofthepancreaticductbycalciumdeposits.ERCPPancreaticcarcinoma:sten18ERCPchangessimilartochronicpancreatitis:theeffectsofagingonthepancreaticductAlthoughagingmaycauseimpressiveductalalterations,itdoesnotaffecttheresultsofpancreaticfunctiontests(i.e.,thesecretintest).theprocedurewasperformedwithinseveralweeksofanattackofacutepancreatitisdifficultDDxbetweenchronicpancreatitisandcarcinoma:ductalstenosisandirregularity.ERCPchangessimilartochroni19followingERCPserumand/orurineamylase:2575%clinicalpancreatitis:uncommon.Pancreatitis:5/300patientsfollowingERCP.morecommoninpatientswithanondilatedpancreaticduct.manometryofthesphincterofOddi:riskofpost-ERCP/manometryacutepancreatitis.PancreaticBiopsyWithRadiologicGuidance:(Percutaneousaspirationbiopsy)DDxpancreaticinflammatorymassandneoplasm.followingERCPserumand/orur20TESTSOFEXOCRINEPANCREATICFUNCTION1.Direct stimulation of the pancreas:IVsecretinorsecretin+CCKcollectionandmeasurementofduodenalcontents2.Indirect stimulation of the pancreas:usingnutrients,AA,FA,andsyntheticpeptidesassaysofproteolytic,lipolytic,andamylolyticenzymes3.Studyofintraluminal digestion products:undigestedmeatfibers,stoolfat,andfecalnitrogen4.Measurement of fecal pancreatic enzymes:suchaschymotrypsinTESTSOFEXOCRINEPANCREATICF21secretintestdetectdiffusepancreaticdiseasephysiologicprinciple:pancreaticsecretoryresponseisdirectlyrelatedtothefunctionalmassofpancreatictissuestandardassay:secretin1CU/kgIVNormal:(1)volumeoutput2.0mL/kg/hr,(2)HCO3-80mmol/L,(3)HCO3-output10mmolin1h.Themostreproducible,highestdiscriminationbetweennormalandchronicpancreatitismaximalbicarbonateconcentrationsecretintestdetectdiffusepa22combined secretin-CCK testmeasure:pancreaticamylase,lipase,trypsin,chymotrypsinProblemsinfunctionaltestoverlapbetweennormal&patientswithpancreatitismarkedlylowenzymeoutputssuggestadvanceddamageanddestructionofacinarcells.frankexocrineinsufficiency:inbothHCO3-andoutputofseveralenzymes.lesserdamage:dissociationbetweenHCO3-&enzymeoutput.dissociationbetweensecretintest&binedsecretin-CCKtestmea23chronicpancreatitisoftenhaveabnormallylowoutputsofHCO3-aftersecretinbuthavenormalfecalfatexcretion.secretintestmeasuresthesecretorycapacityofductularepitheliumfecalfatexcretionindirectlyreflectsintraluminallipolyticactivity.Steatorrheadoesnotoccuruntilintraluminallevelsoflipasearemarkedlyreducedabnormalsecretintestresult:suggestschronicpancreaticdamageispresentnotconsistentlydistinguishbetweenchronicpancreatitisandpancreaticcarcinoma.chronicpancreatitis24tripeptide hydrolysisorbentiromide testmeasureintraluminalchymotrypsinactivityindirectlyPOsyntheticpeptide,N-benzoyl-L-tyrosyl-p-aminobenzoicacid(Bz-Ty-PABA)cleavedbychymotrypsintoBz-Ty+PABA.Normal:thepeptideishydrolyzedinthesmallintestinebychymotrypsinwiththeliberationofPABArapidlyabsorbedandexcretedintheurine.chronicpancreatitis:PABAexcretionissignificantlylowerthancontrolsubjects.sensitivity:60%(4674%)Specificity:90%(ifcoupledwithaD-xylosetest).MeasurementofbloodPABAsensitivity.tripeptidehydrolysisorbenti25intraluminal digestion productsundigestedmusclefibers,stoolfat,andfecalnitrogen,amountofchymotrypsininstool:pancreaticoutputofthisproteolyticenzymechronicpancreatitisandcysticfibrosis:chymotrypsinactivityinstool.normalvaluesmayoccurinpatientswithpancreaticinsufficiency,false-positive:10%ofnormalindividuals.intraluminaldigestionproduct26