Page 191 - Demo

Evaluationofopencranialvaultsurgery18911CASE1-PART2During the second OCVR surgical guides for the demarcation and the reconstructionweremanufacturedandused ThedemarcationtemplatehadauniquefitonthecranialshapeSeveralgapswerecreatedtoindicateclearanatomicallandmarks(greenarrowinFigure4)tocheckifthedemarcationtemplatewasperfectlypositionedUsingthistemplatethedemarcatingphasewasperformedwithinaminuteThisissignificantlyfasterthanusingrulersandlandmarkstotransferaplanning which takesaround10 to15minutesAnotheradvantageis whenbloodorcoolingwaterfromthecraniotomeerasestheplanningthesurgicalguidescouldeasilybeusedagaintoredothedemarcationThereconstructiontemplatesallowthesurgeontomostlyreconstructtheshapeoutsidethepatientwhichstimulatesmanoeuvrabilityandafastplacementofthefixationplatesTheguidesdictatehowthebonesegmentsshouldbepositionedandhowmuchspacebetweenthesegmentswasrequired ThecurvatureoftheguidesenabledthesurgicalteamtofixatethebonesegmentsinthecorrectorientationrelativetoeachotherOntheanteriorandcaudalsideofthereconstructionguidealidwascreatedthatshowedthecorrectpositionandorientationwhenthereconstructedpartwasplacedbackintothepatient ThislidhadanoverlayonthecranialbasetopreventatiltAlthoughthislidwasveryhelpfulwerecommendtomakethislidevenlongertocreatemoreoverlapwiththecranialbaseAfterthecorrectpositionwasensuredthereconstructedshapewasfixatedtothecranialbaseFinallybonestripswerecreatedaroundtheanteriorandcaudalborderstopreventstepsbetweentheskullbaseandthereconstructedpartsFurthermorethebonestripscreatedsomeadditionalvolumeConsideringthepost-opevaluationitcouldbeconcludedthatthepositionandorientationmatchedveryaccuratelyontheplanningAlthoughtherightsideis2mmlower(yellow arrowFigure 3) theleft sidematchedperfectly Thisisin contrastwith the firstOCVR where theincorrectrotationof thesegmentsappeared tohavetomostprominentdeviationfromtheplanning