Der TIPSS zur Therapie des portalen Hyperperfusionssyndrom. Erste Erfahrungen am Small-tor-Size Mini-Pig-Modell The TIPSS in the therapy of portal hyperperfusion syndrome. First experience with the small-for-size mini-pig- model

Introduction:Afterextendedliverresectionorsmall-for-sizelivertransplantationwitharemnant liverparenchymaoflessthan0,5%ofbodyweightoftenportalhyperperfusionhasbeennoticedin theremainingliver.Theinfluenceofthisportalhyperperfusiononthepostoperativeliverdysfunc­ tionhasbeendiscussedcontroversially.Severalexperimentalandclinicalstudiestriedtoreduce theportaloverflow.Withtheideaofaneasilyintroducibleandremovablebypassweevaluatedthe TransjugularIntrahepaticPortosystemicShunt(TIPSS)fortemporaryportaldecompressionina small-for-sizemini-pigmodelandreportaboutourfirstexperiencewiththisnewtherapycombi­ nation. Material and methods:20mini-pigsbetween24and40kgunderwentlaparotomyunder generalanaesthesia.Inallanimalsextendedresectionofthetwoleftlobesandtherightmedian lobewasperformedusingcrash-clamptechnique.Onlytherightlateralsegments(RLS,approxi­ mately25%oflivervolume)left.AftervenasectionoftheV.jugularisinternatheintroductionof theTIPSS(Easy-WallStent,Titan,6mmdiameter,43mmlength)wasperformedunderfluoros­ copiccontrolintotherightlateralhepaticvein.TIPSSwasplacedintothemainportalveinwith fingerguidance.Anticoagulationwas initiallydonewith 10000iEHeparini.v.,followedbylow molecularheparinsubcutaneouslyonceaday.PortalveinandTIPSSflowvelocitywasmeasured 1hourandbeforescarificationafter 72hourswith12MHzDoppler-Duplexultrasound.Results: Theadditionaltimefor placingtheTIPSSwas 60minutesinaverage. In 17animals (85%) the TIPSSwassuccessfullyplaced.Inonecasenohepaticveinwasfoundforcatheterisation(5%), twomini-pigsdiedduetotechnicalreasonsafterextendedhepatectomy(10%). In8of17pigs theTIPSSwasopenafter1hour(47%).In7cases (41%)theTIPSSwasoccludedbythrombosis and2animalsdevelopedapulmonaryembolismwithin1hourafterplacementanddied.3of8 mini-pigs(37,5%) withopenshuntafter1hourdiedwithsignsofliverfailurewithin72hours afterresection.62,5% (n=5) ofallmini-pigswithopenTIPSSsurvived72hoursbutonlyin3 ofthem(37,5%)TIPSS-flowwasdetectedbyultrasound. Conclusion:Thecombinationofsmall­ for-size liverandTIPSS for partialportaldecompression is technically feasibleandeasy. The highrateofpostinterventionalthromboticTIPSSocclusion(14/17,82%)makesthistechnique notapplicableinclinicalsettings.Inthismini-pigmodelthehighocclusionratemightbeexplai­ nablewitharacespecifichypercoagulopathy.