腹壁及腹腔探察.ppt

DissectionofAnteriorAbdominalWall,Withthecadaverinthesupineposition,incisetheskininthemidlinefromthexiphisternaljointtothepubicsymphysis,cuttingaroundtheumbilicus.Thenincisetheskin1inchabovethepubissymphysislaterallyovertoandalittleabovetheiliaccresttothemidaxillarylineonbothsides.Reflecttheskinfromthemidlineanteriorllytothemidaxillaryline,leavingthesuperficialfasciaontheanteriorabdominalwall.,Identifythefattylayerofthesuperficialfascia(Campersfascia)andnotethatitiscontinuousbelowwiththefattysuperficialfasciaofthethighandabovewiththesuperficialfasciaofthethorax.Notethatthefatisgreatestinamountovertheinferiorhalfoftheabdomen.,Notealsotheterminalportionofthesuperficialarteriesandcutaneousnervesinthislayer;alsoobservethesuperficialveins.,IdentifytheMembranousLayeroftheSuperficialFascia(ScarpasFascia).NoteThatItLiesDeeptotheFattyLayerandImmediatelySuperficialtotheaponeurosisoftheExternalObliqueMuscle.InsertaFingerBetweentheMembranousLayerandtheaponeurosisoftheExternalObliqueandSeparateThemInferiorly.,NoteThattheFingerCanBePassedDownMedialtothePubicTubercleAlongtheSpermaticCordandAnteriortotheBodyofthePubisIntothePerineum.LateraltothePubicTubercletheFingerCannotEntertheThigh,However,sincetheMembranousLayerIsAttachedtotheDeepFasciaoftheThighJustBelowtheInguinalLigament.,IdentifytheSuperficialInguinalRingAbovethePubicTuberclebutDoNotDisturbItatThisStage.TheRingIsaTriangularOpeningintheaponeurosisoftheExternalObliqueMuscle.,Makeaverticalincisingthroughthefullthichnessofthesuperficialfasciafromthexiphoidprocesstothesymphysispubis.Withtheaidofascalpelhandle,carefullyreflecttheflapsoffascialaterally,separatingthefasciafromtheaponeurosisoftheexternalobliquemuscle.,Identifyexamplesofanteriorandlateralcutaneousnerves.Removealltheflapsofsuperficialfasciabymakingaverticalincisionthroughthefasciainthemidaxillaryline.,Externalobliquemuscle.Cleanthesurfaceoftheexternalobliquemuscleanditsaponeurosis.Notetheattachmentofthefleshyoriginfromeachofthelowereightribs.Hereitinterdigitateswiththeoriginoftheserratusanteriorandthelatissimusdorsi.,Observethedirectionofthemusclefibers.Identifythelineaalbathatextendsfromthexiphoidprocessdowntothesymphysispubisandisformedbythefusionoftheaponeurosisofthemuscleofthetwosides.,Carefullydefinethemarginsofthesuperficialinguinalringlyingabovethepubictubercle.Notethatitistriangularinshapeandnotround.Inthemale,identifythespermaticcordemergingfromthisapertureandconfirmthatitsoutercovering,theexternalspermaticfascia,isattachedtothemarginsofthering.,Inthefemale,theroundligamentoftheuterusemergesfromthering.Againconfirmthatitsoutercoveringisattachedtothemarginofthering.Identifytheilioinguinalnerveasitemergesfromthelateralpartofthesuperficialinguinalring.,Identifytheinguinalligamentandnotethatitisformedbythelowermarginoftheaponeurosisoftheexternalobliquemuscle.Theligamentisattachedlaterallytotheanteriorsuperioriliacspineandmediallytothepubictubercle.Attachedtothelowermarginoftheligamentisthedeepfascia.,InternalObliqueMuscle.Freetheinterdigitatingoriginsoftheexternalobliquemusclefromthoseoftheserratusanteriorasfarasthemidaxillaryline.Incisetheexternalobliquedownthemidaxillarylinetotheiliaccrest.Nowfindtheplanebetweentheexternalobliqueandtheinternalobliquemuscles.Withthefingers,freetheexternalobliquefromtheinternalobliqueandgraduallyturntheupperpartoftheexternalobliqueforward.,Notethatthefibersoftheinternalobliquemusclerundownwardandbackward,thatis,atrightanglestothefibersoftheexternaloblique.Continuetoreflecttheexternalobliqueforwardandmediallytowardthelateralmarginoftherectussheathtofullyexposetheunderlyinginternalobliquemuscle.Studytheoriginsandinsertionsoftheexternalobliqueanditsinnervation.,Makeaverticalincisionthroughtheaponeurosisoftheexternalobliquemuscle1inchlateraltotherectussheathandextenditdowntoapoint3inchesabovethepubictubercle.Turntheinferiorportionoftheexternalobliquedownwardandcarefullyexaminethesuperiorsurfaceoftheinguinalligament.,Itismostimportantthatyouunderstandtheattachmentsandconfigurationoftheinguinalligament.Notethattheligamentistheinrolledlowermarginoftheaponeurosisoftheexternalobliqueandconfirmagainthatitisattachedtothepubictuberclemediallyandtheanteriorsuperioriliacspinelaterally.,Carefullyfollowtheinguinalligamentmediallytothepubictubercle,followthefibersbackwardasthelacunarligament,andnotetheattachmenttothepectinealline.Notethecontinuityofthelacunarligamentwiththepectinealligament.Studytherelationshipoftheinguinal,lacunar,andpectinealligamentstothefemoralsheath.,Cleanthesurfaceoftheinternalobliquemuscle.Definetheinferiorborderofthemuscleandnoteitsrelationshiptothespermaticcordorroundligamentoftheuterus.Studycloselytheoriginoftheinternalobliquefromtheinguinalligament.Notethattheinternalobliquefibersarisefromthelateralhalfoftheligamentandthereforelieanteriortothedeepinguinalring.,Identifythecremastermusclepassingontothespermaticcordfromtheloweredgeoftheinternalobliquemuscle.Cleantheilioinguinalnerveandfollowitproximallytowhereitemergesfromtheinternalobliquemuscle.,Exposureoftransversusabdominismuscle.Cutthroughtheattachmentsoftheinternalobliquemuscletothecostalmarginandtransectitverticallyalongthemidaxillaryline.Cutthroughtheoriginfromtheiliaccrestandtheinguinalligament.,Insertyourfingersintotheplanebetweentheinternalobliqueandunderlyingtransversusabdominismuscle.Reflecttheinternalobliquemuscleforwardtothelateralmarginoftherectussheathtoexposefullytheunderlyingtransversusabdominismuscleandtheintercostalneres.,Atthelateraledgeoftherectusabdominis,theaponeurosisoftheinternalobliqueisseentosplitandpassanteriorandposteriortotherectusabdominis;theanteriorlayerfuseswiththeaponeurosisoftheexternalobliquemuscle,andposteriorlayerfuseswiththatofthetransversusabdominis.Thisaponeuroticcoveringtotherectusabdominisiscalledtherectussheath.,Transversusabdominismuscle.Cleanthesurfaceofthetransversusabdominisandthevesselsandnervesthatlieonit.Notethatthefibersofthetransversusmuscleruninahorizontaldirection.Identifythelowermarginsofthetransversusabdominismuscleandfollowitsfibersmediallytojoinwiththoseoftheinternalobliquetoformtheconjointtendon.,Examinetheattachmentoftheconjointtendontopubiccrestandthepectinealline.Notethattheconjointtendonliesimmediatelyposteriortothesuperficialinguinalring.Againexaminetheinguinal,lacunar,andpectinealligamentsandnotetheirrelationshiptotheconjointtendon.,Fasciatransversalis.Insertthehandleofthescalpelbetweenthelowermarginofthetransversusabdominismuscleandtheunderlyingfasciatransversalis.Rememberthatthisfascialinestheabdominalwallandformstheposteriorwalloftheinguinalcanallateraltotheconjointtendon.,Thefasciatransversalisistissue-paperthin,andtheextraperitonealfatcanbeseenthroughit.Deeptothefatistheperitonealliningoftheabdominalcavity.,RectusSheath.Therectussheathisalongsheaththatenclosestherectusabdominismuscleandpyramidalismuscle(ifpresent)andcontainstheanteriorramiofthelowersixthoracicnervesandthesuperiorandinferiorepigastricvesselsandlymphatics.Itisformedlargelybytheaponeurosisofthethreeanterolateralabdominalmuscles.,Opentheentirelengthoftherectussheathbyalongitudinalincisionjustlateraltothelineaalba.Identifythemedialedgeoftherectusabdominismuscle.Raiseitsmedialedgeand,withthefingerorbluntendoftheforceps,verifythatitispossibletoseparatetherectusmusclefromtheposteriorlayerofthesheath.,Noteandpreservethenervesandvesselspassingthroughtheposteriorwallofthesheathintothelateralpartofthemuscle.,Reflectthelateralpartoftheanteriorlayerofthesheathbycuttingfreetheattachedtendinousintersectionsoftherectusmuscle.Examineagainthelineaalbaandrealizethatitisformedbythefusionoftheaponeurosesofthethreelateralmusclesoftheabdominalwallonthetwosides.Itextendsfromthexiphoidprocessdowntothesympgysispubisandseparatestherectusabdominismusclesonthetwosides.,UnderstandWhatIsMeantbytheTermlineasemilunaris.ThisIsaCurvedRidgeFormedbytheLateralMarginoftherectusabdominisMuscle.,CleantherectusabdominisandIdentifythepyramidalisMuscleifPresent.TransecttherectusMuscleatItsMiddleandRaisetheUpperandLowerEnds,CuttingtheNervesThatEnterIt.IdentifytheSuperiorepigastricArteryThatEnterstherectusSheathbyEmergingFromBeneaththeLowerMarginoftheSeventhCostalCartilageandPassingDownPosteriortotherectusMuscle.,Notealsotheinferiorepigastricarterythatascendswithinthesheathfrombelow.Verifytheoriginandinsertionoftherectusabdominisandthepyramidalismuscles.Finally,removebothofthesemuscles.,Carefyllyexaminetheanteriorandosteriorwallsoftherectussheathandverifytheirformationfromtheaponeurosesoftheanteriorabdominalmuscles.Notethattheposteriorwallendsbelowatthearcuateline,wheretheaponeurosesoftheinternalobliqueandtrasversusabdominismusclespassanteriortotherectusmuscle.,Cutfreetheattachmentsoftheinternalobliqueandtrasversusabdominismusclesfromthecostalmargin.Incisethelattermusclealongthemidaxillarylinetotheiliaccrest.Trytopreservetheunderlyingperitoneumintact.Reflectalltheabdominalmusclesandthefasciatransversalisinferiorlyasaunitbybluntdissection.Cutaroundtheumbilicustopreserveitsconnectionwiththeligamentumteresoftheliver.,Deepinguinalring.Beforedestroyingthefasciatransversalisintheinguinalregion,pullonthespermaticcordorroundligamentoftheuterusfromtheanteriorsurfaceandidentifythedeepinguinalringandtheinternalspermaticfascia.Confirmthatthedeepringlieslateraltotheinferiorepigastricvessels.,TheAbdominalCavity,Peritoneum.Theperitoneumisaserousmembraneliningthewallsoftheabdominalcavityandclothingtheabdominalviscera.Theparietalperitoneumlinesthewallsoftheabdominalcavity,andthevisceralperitoneumcoverstheabdominalorgans.,Theperitoneumsecretesasmallamountofserousfluid,whichlubricatesthesurfacesoftheperitoneumandfacilitatesfreemovementbetweentheviscera.Thepotentialspacebetweentheparietalandviscerallayersoftheperitoneumiscalledtheperitonealcavity.,Theperitoneumhasthefollowingimportantarrangements:1.Theperitonealcavityisdividedintothegreaterandthelessersac.Thegreatersacisthemaincompartment,anditextendsacrossthewholebreadthoftheabdomenandfromthediaphragmtothepelvis.Thelessersacisthesmallercompartment,anditliesbehindthestomach,asadiverticulumfromthegreatersac;itopensthroughanovalwindowcalledtheopeningofthelessersac,ortheepiploicforamen.,2.Amesenteryisatwo-layeredfoldofperitoneumthatattachespartoftheintestinestotheposteriorabdominalwall,anditincludsthemesenteryofthesmallintestine,thetransversmesocolon,andthesigmoidmesocolon.,3.Anomentumisatwo-layeredfoldofperitoneumthatattachesthestomachtoanotherviscus.Thegreateromentumisattachestothegreatercurvatureofthestomach,andithangsdownlikeanaproninthespacebetweenthecoilsofsmallintestineandtheanteriorabdominalwall.,Itisfoldedbackonitselfandisattachedtotheinferiorborderofthetransversecolon.Thelesseromentumslingsthelessercurvatureofthestomachtotheundersurfaceoftheliver.Thegastrosplenicomentum(ligament)connectsthestomachtothespleen.,4.Theperitonealligamentsaretwo-layeredfoldsofperitoneumthatattachthelessmobilesolidvisceratotheabdominalwalls.Theliver,forexample,isattachedbythefalciformligamenttotheanteriorabdominalwallandtotheundersurfaceofthediaphragm.Themesenteries,omenta,andperitonealligamentsallowbloodvessels,lymphatics,andnervestoreachthevariousviscera.,OpeningofAbdominalcavityandInspectionofItsContents.,Whentheperitonealcavityhasbeenopenedbymakingatransverseincisionthroughtheparietalperitoneumliningtheanteriorabdominalwallattheleveloftheumbilicus,identifythreefoldsofperitoneumthatconvergeontheumbilicusfrombelow.Thesecoverthetwolateralumbilicalligamentsandthemedianumbilicalligament.,Belowtheleveloftheanteriorsuperioriliacspines,twoadditionalfoldsmayberecognized,duetotheunderlyinginferiorepigastricarteries.,Examinethefalciformligament,whichextendsfromtheumbilicustotheliver.Identifytheligamentumteresinthefreemarginofthefalciformligament.Cuttheperitoneumalongthecostalmargin,exceptwherethefalciformligamentoftheliverisattached.Reflecttheremainderoftheperitoneuminferiorlybycuttingitdownthemidaxillarylineoneachside.,Studytheabdomin