MORPHOLOGICAL STUDY OF SURGICALLY OBTAINED HUMAN COCHLEAR SPECIMENS-TECHNICAL ASPECTS

(整期优先)网络出版时间:2014-01-11
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ObjectToexploretheproceduresinper-operativeharvestingandmanagementoffreshhumancochlearspecimensforresearch.MethodsDuringtrans-cochlearsurgerytoremovelargepetro-clivalmeningiomascausinglife-threateningcompressiononthebrainstem,cochleaearenormallydestroyedanddrilledawayinordertoreachtheapicalpetrousandclivusregion.Insteadthecochleacanbedissectedoutafterethicalper-missionwasobtainedfromthelocalethicalcommittee(EPN)andallowancegainedfromthepatients.Sur-geryisperformedbyateamconsistingofoto-andneurosurgeonsasatwo-dayprocedurewithtotalpetro-sectomyincombinationwithaninferiorre-routingofthefacialnerve.Fixationofthecochleaewasdoneintheoperatingroomassoonasthespecimenshadbeenseparatedfromthetemporalbones.Decalcificationbeganafterhours’toovernight’sfixationfor4weeks.Sectioningparalleltothemodiolus(mid-modiolus)wasperformedwithacryostatmicrotome.Thesectionsweresubjectedtoimmunofluorescence(IF).ResultsUsingfreshlyprepared4%paraformaldehyde(PFD)solution,adequatefixationoffineinnerearstructureswasachievedwithhours’immersionofthecochlearspecimens.Decalcificationin6.2%ethylenedi-amine-tetraceticacid(EDTA)solutionfor4weeksyieldedathoroughlydecalcifiedcochlea.Experiencesinprocessing14humancochleaeandanalysingmainlandmarksinfivehumaninnerearplastic/siliconecastsshowedthattheovalwindow/stapesfootplatearebackwardtilted,atanangleabout15degrees,fromtheplaneperpendiculartothemodiolaraxis.Thedistancefromthemodiolarapextotheanteriorborderoftheovalwindow/footplateintheseinnerearcastsmeasuredbetween4and5mm.HighqualityIFstainingwasobtained.ConclusionSurgicallyobtainedhumancochlearspecimen,whenproperlyprocessed,containside-allypreservedantigenicityforimmunohistochemicalstudy.Adequateorientationduringsectioninghelpsob-tainoptimalmid-modiolarsectionsshowingfi