EastAsianConferenceofNeurointervention2016Venue: KobeInternationalExhibitionHall2 http://kobe-cc.jp/english/tenji/index.html 6-11-1Minatojima-Nakamachi,Chuo-ku,Kobe650-0046,Japan Tel;+81-78-302-1020,Fax;+81-78-302-1870Dates: Registration July2(Sat)18:30-atWelcomePartyinKobePortopiaHotel July3(Sun)7:00-atConferenceVenue Conference July3(Sun)8:00-16:10

WelcomeParty July2(Sat)18:30 GrandBanquetRoom“Owada” atKobePortopiaHotelSouthWing1F

Registrationfee 10,000JPYor100USD(cashonly,WelcomePartyincluded)

Language English

Dresscode SmartCasual

Map

Director :MoonHeeHan,JainminLiu,NobuyukiSAKAICo-Director :MasayukiEzura,ShigeruMiyachiProgramChairman :YasushiItoSecretary :ChiakiSakaiFaculty:〈China〉 BingFang ConghuiLi JiangLiu JieqingWan YinaWu PengfeiYang QianZheng QingZhu YuZhou ChaoZou 〈Korea〉 SeungKugBaik JoonHuh HaeWoongJeong Jin-YoungJung WooSangJung Hyun-SeungKang Nam-JoonLee SangHunLee YoungSeoLee WoongJaeLee JungHyunPark Dong-HyunShim ShangHunShin DongHyunYoo WoongYoon 〈Japan〉 YukikoEnomoto ToshiyukiFujinaka HitoshiHasegawa MikitoHayakawa ToshioHigashi MasaruHirohata AkioHyodo KojiIihara HirotoshiImamura ToshihiroIshibashi AkiraIshii TakashiIzumi EiichiKobayashi RyushiKondo NaoyaKuwayama YujiMatsumaru YasushiMatsumotoYuichiMurayama IchiroNakahara ShigeruNemoto YasunariNiimi HidenoriOhishi TetsuSato JunichiroSatomi KittipongSrivatanakul KenjiSugiu WaroTaki MichihiroTanaka SatoshiTateshima TomoakiTerada TomoyukiTsumoto WataroTsuruta HiroshiYamagami ShinichiYoshimura

InstructionforspeakerOralsession1. PresentationTime;Eachspeakerhave10minutesincludingdiscussiontime.Pleaseremainenough

timetodiscuss.2. PleaseprepareinyourcomputerandpleasepreviewyourpresentationdataatthePCCenterat

least1hourpriortoyourpresentation,locatedatthefrontofroom.3. Audioplaybackispossible,ifyouwanttouse,letusknow.4. WeprepareaMiniD-sub15pinPCcableconnector.IfyourPCisnotcompatiblewiththiscable

connector,pleasebringanadaptortoconnectyourPCtotheMiniD-sub15pinPCcableconnector.And,pleasebringyourACadapterwithyou.

5. TheresolutionoftheLCDprojectorisXGA(1024x768).Ifyourcomputerrequiresaresolutionsettingtobechanged,pleasechangethissettingbeforehand.

6. Pleasealsobringyourpresentationdataonamedia(eitheronUSBflashmemoryorCD-R)asabackupfile.

7. AftercheckingyourdataatthePCCenter,pleasebringyourPCtotheOperationDeskinthesessionroom30minutespriortothestarttimeofyoursession.

8. Pleasebeseatedinthenextspeaker’sseatslocatedatthefrontleftofyoursessionroomatleast20minutespriortoyourpresentationstart.

9. Remotepresentationsystemisequippedintheeachsessionroom.YouhaveaTFTmonitor,mouseandUSBkeyboardonthepodiumtooperateyourpresentation.

10. Followingtheconclusionofyoursession,wewillreturnyourcomputerattheOperationDesk.PleasecometotheOperationDeskpromptlytocollectit.

Welcome to EACoN2016 Dear, Friends On the behalf of organizing committee, we are pleased to welcome all of you to East Asian Conference on Neurointervention (EACoN) 2016 in Kobe, Japan on 3rd July collaboration with Brush-up Seminar of Neuro-Endovascular Therapy (BSNET) 2016 on Jun 30th〜July 2nd. This year, considering recent development of flow diverters, we planned featured symposium, “Flow diverter in East Asia”. Another topics of Neurointervention are also presented in the meeting. According to the tradition and spirit of EACoN, we strongly believe all attendants of the meeting will strengthen scientific collaboration and friendship through open hearted presentations and discussions. We are looking forward to seeing all of you in Kobe. Best regards,

Yasushi Ito President of EACoN2016

Nobuyuki Sakai Secretory General of EACoN2016

TIMETABLE Speaker/Moderator Affiliation,Nationality7:00 Registration 8:00 WelcomeMessage NobuyukiSakai Japan

8:05 OpeningCeremonySeungKugBaik KoreaJieqingWan ChinaYasushiIto Japan

8:15 Session1 "Aneurysm1"MoonHeeHan KoreaConghuiLi ChinaMasayukiEzura Japan

1-1 Virtual stent and LVIS Jr. for AcoA / MCAunrupturedaneurysm NaotoKimura Iwateprefecturalcentral

hospital,Japan

1-2 Treatment of complex intracranial aneurysmsusingLVISstent:ChanghaiExperience PengfeiYang

Changhai Hospital, SecondMilitary Medical University,China

1-3 T-configured stenting with Enterprise VRD2:technicaltips KeisukeSato NiigtaUniversity,Japan

1-4Duble Stents Assisted Coil Embolization ofRuptured Supraclinoid Blood Blister-LikeAneurysmofInternalCarotidArtery

BingFang Second affiliated hospital ofZhejiangUniversity,China.

1-5 Interobserver variability of aneurysmmorphology:discriminationofthedaughtersac WooSangJung Gangnam Severance Hospital,

YonseiUniversity,Korea

9:20 Sessinon2 "Aneurysm2"QingZhu ChinaYujiMatsumaru JapanNamJoonLee Korea

2-1Microcatheter Looping Facilitates Access to Boththe Acutely Angled Parent Artery and CerebralAneurysmsforEffectiveEmbolization

ConghuiLi China

2-2ProximalAnteriorCerebralArteryAneurysms(A1segment):RetrospectiveReviewofCharacteristicsandEndovascularTreatment

HaeWoongJeong InjeUniversityBusanPaik Hospital,Japam

2-3Coil embolization for unruptured ICA bifurcation aneurysmviaanterior communicatingarteryduetocomplicatedanatomy:casereport.

YuTakahashi Okayama University GraduateSchoolofMedicine,Japan

2-4 SafetyofPreproceduralAntiplateletmedicationincoilembolizationofSAH JungHyunPark

Dongtan Sacred HeartHospital, Hallym University,Korea

2-5 DelayedClopidogrelHyper-responseAfter NeuroendovascularTreatment HidekiEndo NakamuraMemorial

Hospital,Japan

2-6Low-dose prasugrel premedication forendovascular treatmentofintracranialaneurysms

Hyun-SeungKang Seoul National UniversityHospital,Korea

10:10 Break

10:20 FeaturedSymposium "FlowdiverterinEastAsia"

HidenoriOishi JapanSeungKugBaik KoreaYuZhou China

S-1Endovascular therapy of intracranial aneurysmwith Pipeline Flex : consecutive 30 cases inJuntendoUniversityHospital

KohsukeTeranishi JuntendoUniversity SchoolofMedicine,Japan

S-2 Treatment of giant MCA aneurysm using flow-diverterwithpreservationofarterialbranch Jin-YoungJung Dong-EuiMedicalCenter,

Busan,Korea

S-3

Parent artery reconstruction for large or giantcerebral aneurysms using a Tubridge flowdiverter(PARAT): a multicenter, randomized,controlledclinicaltrial

YuZhou

China

S-4Innovation of Endovascular Treatment StrategyforLargeCarotidCavernousAneurysms -SafetyandEfficacyofFlowDiverter

OsakaMedicalCollage, JapanShigeruMiyachi

S-5

Dynamic Volume Change of Thrombosed GiantAneurysmafterFlow-DivertingStentDeployment:Quantitative Assessment by ComputedTomographicVolumetricImage

Chung-AngUniversity CollegeofMedicine,Korea

WoongJaeLee

S-6Temporal changes of intra-aneurysmal pressureafter placement of Pipeline Embolization Deviceusingelastase-inducedaneurysmmodelinrabbits

KokuraMemorialHospitalJapanHideoChihara

11:20 Sessinon3 "CAS,stroke"ShangHunShin KoreaShinichiYoshimura JapanJieqingWan China

3-1 ComprehensiveHybridStrategyforCarotidArteryStenosiswith“ToyamaCarotid8”rules. NaoyaKuwayama UniversityofToyama,Japan

3-2Experience of staged angioplasty for carotidartery stenosis to avoid hyperperfusionsyndrome

KazutakaUchida Hyogo College of Medicine,Japan

3-3 Staged Carotid Artery Stenting in Patients withSevereCarotidStenosis:MulticenterExperience DongHyunYoo Seoul National University

Hospital,Korea

3-4A single center retrospective study of stagedangioplasty for cerebral hyperperfusion high riskgroupofcervicalcarotidarterystenosis.

TakahiroMorita Sendai Medical Center, Japan

3-5Long-term outcome of endovascularrecanalization in patients with Chronic InternalCarotidArteryocclusion:asingle-center

JieqingWan China

3-6Intracranial Angioplasty and Stenting for Crebral Artherosclerosis : Results of 93 ConsecutivePatients

DaehyunHwang DongtanSacredHeart Hospital,Korea

3-7Acute stroke showing major intracranial vesselocclusion: characteristics of cardioembolics andatherosclerosisrelatedinsitustenosis/occlusion

NobutakaHorie NagasakiUniversitySchool ofMedicine,Japan

12:40 Luncheonlecture(Daiichi-Sankyo)MasaruHirohata KurumeUniversity

YasushiIto NiigataUniversity

Platelet Reactivity and Recurrence of IschemicStroke HiroshiYamagami National Cerebral and

CardiovascularCenter,Japan

Endovascular treatment of complex cerebralaneurysms AkiraIshii KyotoUniversity,Japan

13:40 Break

13:50 Session4 "CCF,DAVF,AVM"JiangLiu ChinaHaeWoongJeong KoreaYasushiMatsumoto Japan

4-1 RetreatmentbyDetachableBalloonforRecurrent QingZhu China

TraumaticCarotidCavernousFistulae

4-2 Usefulness of DynaCT in the EndovascularTreatmentofDCCF ChaoZou China

4-3The feasibility of hybrid operation room for thetreatment of isolated type dural arteriovenousfistula

HiroakiNekiSaitamaMedicalUniversity International Medical Cente、Japan

4-4Endovascular Embolization for ComplexIntracranial Dural Arteriovenous Fistula underProtectionofIntra-SinusBalloon

QianZheng China

4-5

Penetrable large shunting point in intracranialduralarteriovenousfistulas:providingalternativeaccess route to transarterial intravenousembolization

Dong-HyunShim PusanNationalUniversity YangsanHospital,Korea

4-6 Endovascular Treatment of the DAVF at thePetrousApexRegion JiangLiu China

4-7 TargetembolizationforrupturedcerebralAVM RyushiKondo KitasatoUniversity,Japan

15:00 Session5 "Thrombectomy"KenjiSugiu JapanPengfeiYang ChinaWoongYoon Korea

5-1Parametric Digital Subtraction AngiographyImaging forObjective Evaluationof EndovascularTreatmentinCerebrovascularDiseases

YinaWuChanghaiHospital,Second MilitaryMedicalUniversity,China

5-2

Interactionbetweenthestentstrutandthrombusas characterized by contrast-enhancedhigh-resolution cone-beam computedtomography during deployment of the Solitairestentretriever

TomoyukiTsumoto NationalKyushuMedical Center,Japan

5-3 Histological examination of vascular damagecausedbystentretrieverthrombectomydevices DaisukeArai KyotoUniversity,Japan

5-4 Relay Balloon Technique for Recanalization ofAcuteSymptomaticProximalICAocclusion SangHunLee

AsanMedicalCenter, UniversityofUlsanCollege ofMedicine,Korea

5-5Recentour resultsofendovascular recanalizationby stent retriever for middle cerebral arteryocclusion

YuchiMatsui KobeCityMedicalCenter GeneralHospital,Japan

5-6Theimpactoftortuosityofthetargetvesselson intracranial hemorrhage after acutethrombectomy

ManabuShirakawa HyogoCollegeofMedicine, Japan

16:00 ClosingRemarks YasushiIto ChaimanofEACoN2016

Session1 “Aneurysm1”

1-1)VirtualstentandLVISJr.forAcoA/MCAunrupturedaneurysmNaotoKimura,MichikoYokosawa,KazushiHara,andTakayukiSugawaraNeurosurgicaldepartmentofIwateprefecturalcentralhospital,Morioka,Japan LVISJr.isalatestdeviceforneckbridgingstentavailableinJapan.ItiscompatibleforHeadway17thuscanapproachmoredistalthanpreviousstent.OntheotherhandSIEMENSworkstationattachedtoangiosuitecanconstructvirtualstentfrom3D-DSAdata. Weevaluate theefficacyof combinationofVirtual stentandLVIS Jr. forAnterior communicatingartery (AcoA) /middlecerebralartery(MCA)unrupturedaneurysm. 88aneurysmsweretreatedinIwateprefecturalcentralhospitalfromMay.2015toMay2016.Intotal,3MCAand5AcoAaneurysmsweretreatedusingLVISJr.Alltreatmentwereunderlocalanesthesiaanddualantiplateletdrugs(Aspirin100mg,Chropidogrel75mg/day)weregivenatleast1weekbefore treatment. Virtualstentwasperformedinallcases.LVISJr.wasdeployedatsuitableplaceinallcaseswithoutanytrouble.Sixcasesendedincompleteobliterationorsmallneckremnant,twocasesfinishedwithbodyfiling. LVIS Jr. is nitinol braded stent and has small diameter. Thus, high performance is shown for AcoA/MCA AN. Howeverwhen it deployed too distal from curvature, success rate of proximal stent opening getworse. Virtual stent is useful tovisualizestentdiameterandlengthatparentarteryonpreferredposition.CombinationofVirtualstentandLVISJr.isusefulforAcoA/MCAaneurysmtreatment.1-2)The safety and efficacy of low profile visualized intraluminal support (LVIS) stents in assisting coil embolization ofintracranialsaccularaneurysms:asinglecenterexperiencePengfeiYang,ZhengzheFeng,YibinFang,YiXu,BoHong,WenyuanZhao,JianminLiu,QinghaiHuangDepartmentofNeurosurgery,ChanghaiHospital,SecondMilitaryMedicalUniversity,Shanghai,China,200433ABSTRACTBackground：The lowprofile visualized intraluminal support (LVIS) device is a new generation of selfexpanding braidedstents recently introduced intoChina for stent assisted coilingof intracranial aneurysms. This studyassessed the clinicalsafetyandefficacyoftheLVISstentforembolizationofintracranialsaccularaneurysms.Methods：PatientswithintracranialsaccularaneurysmstreatedusingtheLVISdeviceinourcenterbetweenApril2014andDecember2014werereviewed.Theprimaryoutcomeswereproceduralsafety,targetaneurysmrecurrence,andmid-termfollow-upofclinicalandangiographicoutcomes.Results：97patientswith intracranialsaccularaneurysmsweretreatedusingtheLVISstent,with100%technicalsuccessrate. No mortality was observed. One patient had transient deficit (1/97, 1.0%). Immediate angiographic outcomeevaluationshowedcompleteocclusionin28(28.8%)andneckremnantin39(40.2%)ofthe97patients,respectively.Ofthe76(78.35%)patientswhounderwentangiographicfollow-upatameanof8.1months,completeocclusionwasachievedin64(84.2%)patients. Intheremainingpatients,neckremnantinnine(11.8%)andresidualsacinthree(4%)patientswereobserved.Noneofthepatientshadanytargetaneurysmrecurrence,andthemortalityratewas0%.Conclusions：TheLVISstentissafeandeffectiveinthetreatmentofintracranialsaccularaneurysms.1-3)T-configuredstentingwithEnterpriseVRD2:technicaltipsKeisukeSato,YasushiIto,HitoshiHasegawa,KazuhikoNishino,YukihikoFujiiDepartmentofNeurosurgery,BrainResearchInstitute,NiigataUniversity, Niigata,JapanIntroduction: Indication of aneurysmal coil embolization has been expanding after introduction of Enterprise vascularreconstructive device (VRD).Moreover, Enterprise VRD2 improved in conformability has been launched already both inJapanandKorea,anditwillbesoonlaunchedin2017inChina. Althoughithasbeendifficulttotreatwideneckaneurysmineithertypeofterminalorsidewallnomatterwhetherclippingorcoiling,wecannowsuccessfullyperformthecoilembolization for suchkindofaneurysmsby thedevelopmentof thedualstenttechniques,suchasY-configuredandT-configuredstent-assistcoilembolization. Sowe report twocases thosewereperformedcoil embolizationwithT-configured stentingusingEnterpriseVRD2 inourinstitutionin2016.The procedure was carried out under general anesthesia. Microcatheter was advanced into the aneurysm with jailingtechniqueinprinciple.

Casepresentation:Case1 A68y.o. femalewasdiagnosedwithanunruptured left IC-PCaneurysm.LeftPcomwasfetaltypeand itsorificewas locatedontheaneurysmalsidewallbesidetheneck.Wedecidedto introducefirstVRD2 intoPcom,thentoadvancesecondVRD2 into ICmakingT-configured shape.Thecatheterization intoPcomwasdifficultbutwasachievedwithwraparoundtechnique.AftersuccessfulT-configuredstenting,coilembolizationwasmadewithoutanyneurologicaldeficit. Case2 A71y.o. femalehadanunruptured right IC-PC incidentalaneurysm.WeplannedT-configuredstentingwith thesameprocessascase1.ButthecatheterizationintoPcomwassodifficultthatweneededtheexchangesofmicrocathetersandmicroguidewires several times. Finallywe achieved T-configured stenting ideally and stent-assisted coil embolizationwas finished successfully. But after the procedure, this patient had moderate left hand motor weakness. MRIdiffusion-weighted imagingshowedmultiplesmall infarctionsat righthemisphere.Nowthesymptom isgetting improvedandshecontinuesrehabilitations.Discussion/Conclusion:T-configuredstent-assisttechniquecanachievedensecoilpackingintotheaneurysm,preservingtheparent vessels while avoiding the confliction of two stents. So it is quite possible that T-stenting reduce the risk ofthromboemboliccomplicationcomparedwithY-stenting.However, it seems tobemoredifficult todeploystentswithouttheinterspacebetweeneachstent.Becausethesystemofneckbridgestentmakesitdifficulttopredicttheoptimalpositionoftheproximalflareduringdeploymentperiod eveninexpertphysicians.WewillreportseveralspecifictipsandattentionsregardingT-configuredstentingtechniquethroughthevaluablepracticalexperiences.

1-4)DubleStentsAssistedCoilEmbolizationofRupturedSupraclinoidBloodBlister-LikeAneurysmofInternalCarotidArtery.BingFang,JingXu,XianyiChen,DingyaoJiang,JunYu SecondaffiliatedhospitalofZhejiangUniversity,DepartmentofNeurosurgeryHangzhou,China.OBJECTIVE: Bloodblister-likeaneurysms(BBAs)areuniqueduetotheirhighriskofrecurrentbleedingassociatedwiththeirfragileneck.The best treatment for BBAs is still controversial. This paper sought to evaluate the safety and efficacy of double stentoverlappingandassistedcoilinginthetreatmentofBBAs.METHODS: eightconsecutivepatientswithrupturedBBAsmanagedwithdoublestentoverlappingandassistedcoilingwereenrolledinthisstudy.Theclinicalcharacteristics,proceduraldata,angiographicoutcome,andfollow-upresultswerereviewed.RESULTS: doublestentoverlappingandassistedcoilingweresuccessfullyperformedinall8cases.Theinstantangiographicresultwastotalocclusionin6cases,residualaneurysmin2cases.Angiographicfollow-upsrevealedstableinall6caseswhichweretotal occlusion. One of the residual aneurysmswas stable and another onewas progressed. Themodified Rankin Scalescoreat12-16monthsfollow-upwas0in7cases,1in1case.CONCLUSION: Stent-assistedcoilinganddoubleoverlappingstentsarefeasibleandsafeforBBAs.1-5)Interobservervariabilityofaneurysmmorphology:discriminationofthedaughtersacWooSangJung.SangHyunSuhDepartmentofRadiology,GangnamSeveranceHospital,YonseiUniversity,Seoul,KoreaBackgroundandPurpose:Severaldefinitionshavebeenproposedtodistinguishthedaughtersacwhentreatingunrupturedintracranialaneurysms.Theaimofthisstudywastoevaluate interobservervariabilityofaneurysmmorphology, includingthe daughter sac, using criteria from the International Study of Unruptured Intracranial Aneurysms (ISUIA) and theUnrupturedCerebralAneurysmStudyofJapan(UCAS). Materials and Method: After approval by the institutional review board, we analyzed three morphological features(daughter sac, lobulation, and irregularmargin) from the ISUIA and UCAS using angiographic images from 102 saccularaneurysms.Fourindependentreadersinterpretedeachmorphologicalcriterionusingdichotomizedscales(existenceornot).Theκstatisticwasusedtomeasureinterobserveragreement,andκ>0.6wasconsideredsubstantialagreement..Results:Fordiscriminationofthedaughtersac,interobserveragreementamongthefourreaderswassubstantialusingtheUCAScriteria(k=0.626fortwodimensional(2D)and0.659forthree-dimensional(3D)images)butnotfortheISUIAcriteria(k=0.487for2Dand0.473for3Dimages;significantdifference).Irrespectiveoftheimagesused,pairwisepooledκvaluesfortheUCASwere>0.6,exceptforonecase(scoreof0.54betweenreadersAandB).Regardingtheproportionofpositivereads,therewasasignificantdifferencebetweenreadsforthedaughtersacusingtheUCASandISUIAcriteria.Conclusion:Fordiscriminationofthedaughtersac,theUCASdefinitionshowedahigherreliabilitythantheISUIA.However,a further prospective study is necessary to validate this definition as the treatment standard for unruptured intracranialaneurysms.

Session2 “Aneurysm2”

2-1)MicrocatheterLoopingFacilitatesAccesstoBoththeAcutelyAngledParentArteryandCerebralAneurysmsforEffectiveEmbolizationLICong-hui. DepartmentofNeurosurgery,ShijiazhuangFirstHospital,Shijiazhuang,050011,ChinaAbstract：Objective To discuss the safety and effectiveness of microcatheter looping technique for super-selectivecatheterizationintoacuteangleparentvessel. Methods The data of 21 patients using microcatheter looping technique for acute angle parent vessel were analyzedretrospectively.Thistechniquewasused innineteenpatientswhosetenaneurysmswereattheposteriorcommunicatingarteries,2atopticalarterysegmentofinternalcarotidartery(ICA),4atM1segmentofmiddlecerebralartery(MCA)and3atposteriorinferiorcerebelarartery(PICA),andintheothertwopatientswhodevelopedAVMorAVF.Microcatheterαloopwasusedtosuper-selectparentvessel. Results The microcatheter looping technique was successfully used in twenty-one patients while only one patientdevelopedmildvasospasm.ConclusionsMicrocatheterloopingtechniquetosuper-selectacuteanglebranchwillbemoresafelyandeffectively.KeyWords： microcatheter；loopingtechnique；endovasculartreatment；aneurysm；acute-anglebifurcation2-2)Proximal Anterior Cerebral Artery Aneurysms (A1 segment): Retrospective Reviewof Characteristics and EndovascularTreatmentYoung Seo Lee2, HaeWoong Jeong1, JinWook Baek1, Sung Tae Kim2, Jung Hwa Seo3, Sung-Chul Jin4, Soon Chan Kwon5,MyongJinKang6,TaeHongLee7,SeungKugBaik81.InjeUniversityBusanPaikHospital,DepartmentofRadiology2.InjeUniversityBusanPaikHospital,DepartmentofNeurosurgery3.InjeUniversityBusanPaikHospital,DepartmentofNeurology 4.InjeUniversityHaeundaePaikHospital,DepartmentofNeurosurgery5.UlsanUniversityHospital,DepartmentofNeurosurgery6.Dong-AUniversityHospital,DepartmentofRadiology7.PusanNationalUniversityHospital,DepartmentofRadiology8.PusanNationalUniversityYangsanHospital,DepartmentofRadiologyBackgroundandPurpose:Aneurysmsof the proximal segment of the anterior cerebral artery (A1 segment) are rare andchallenging to treat. The aim of this studywas to review the characteristics and clinical outcome after treatment of A1segmentaneurysmsviaendovascularapproach.MaterialsandMethod:Sixtyninepatientswith69A1segmentaneurysmswhichweretreatedviaendovascularapproachinInje University Busan Paik Hospital, Inje University Haeundae Paik Hospital, Ulsan University Hospital, Pusan NationalUniversityHospital,PusanNationalUniversityYangsanHospital, andDong-AUniversityHospital fromSeptember2005 toApril 2016 were retrospectively reviewed. Each aneurysm was classified as proximal, middle, or distal by location.Characteristics of aneurysms, technique for treatment, complication of treatment, and angiographic outcome of thepatientswereassessed.AngiographicoutcomewasassessedbyRaymondclassification.Alsofollowupradiologicoutcomeswereassessed.Results:Total69aneurysmswereretrospectivelyreviewed.Aneurysmswereclassifiedasproximal(n=46),middle(n=10)anddistal(n=13).Posteriororposterosuperiordirectionwasthemostcommondirection(n=45).Singlemicrocathetertechniquewasmostcommonlyusedtechniqueforembolization(n=33),followedbyballoonassisted(n=14),stentassisted(n=13),andmultiplemicrocathetertechnique(n=9).Completeocclusionwasachievedin42aneurysms.Residualneckwasnotedin17aneurysmsand10aneurysmsshowresidualaneurysm.Total40patientswereperformedfollow-upstudy,withMRAorDSA,meanintervaloffollow-upwas21.3months.Amongthemstableaneurysmalocclusionwasobtainedin36ofthepatients.Conclusion:EndovasculartreatmentofA1segmentmightbeperformedsafelyandefficaciously,consideringtheanatomicalconfigurationofaneurysmswithappropriatetechnique.2-3)Coil embolization for unruptured ICA bifurcation aneurysm via anterior communicating artery due to complicatedanatomy:casereport.Yu Takahashi, Kenji Sugiu, Tomohito Hishikawa, Masafumi Hiramatsu, Jun Haruma, Yuji Takasugi, Yukei Shinji, ShingoNishihiro,NaoyaKidani,IsaoDate

DepartmentofNeurologicalSurgery,OkayamaUniversityGraduateSchoolofMedicine,JapanBackground andAims: Persistent primitive trigeminal artery (PPTA) iswell recognized variant artery of cerebral artery. Itrarelyexistsbutitoftenassociatedwithaneurysm.WereportasuccessfulcaseofcoilembolizationfromcontralateralICAviaanteriorcommunicatingartery(AcomA)forICbifurcationunrupturedaneurysmcoexistwithPPTA.Case:A45-year-oldmanwith incidentally foundaneurysmwas referred toourhospital.DSA showed left ICAbifurcationunrupturedaneurysm(Fig.1)andPPTA(Fig.2)withhypoplasiaofipsilateralcervicalICA(Fig.3).Endovasculartreatmentwasplannedthrough1)ipsilateralICA,2)contralateralICAviaAcomA,3)VA-BAviaPPTA.First,wetriedipsilateralICAapproachtotheaneurysmbutwecouldnotadvanceguidingcatheter,becauseICAwasnarrowandcatheterdidawedgetothevessel.VA-BAapproachwasseemeddifficultbecausetortuosityofthevessel.SoweplacedaguidingcatheteratcontralateralICAandderivedamicrocathetersuccessfully into theaneurysmviaAcomA.Thenweperformedcoilembolizationwithgoodangiographicalresult.Postoperativecoursewasuneventful,andhedischargedwithoutneurologicaldeficit. Conclusion: We report a rare case of IC bifurcation aneurysm with PPTA. When access to aneurysm is difficult due toanatomicalvariant,anotheraccessrouteshouldbeconsideredviacommunicatingarteries. (Fig.1) (Fig.2) (Fig.3)

2-4)SafetyofPreproceduralAntiplateletmedicationincoilembolizationofSAHJungHyunPark,IlYongSin,HyungSikHwang,HyoSubJeon.DongtanSacredHeartHospital,HallymUniversity,SouthKoreaBackground and Purpose: Preoperative antiplatelet medication for coil embolization during acute period of SAH is notcommon.We tested thehypothesis thatpreprocedural antiplateletmedication inSAHmayprevent complicationsdue toischemiaorinducedbleedingMaterials and Method: Retrospectively reviewed 23 patients who received preprocedural antiplatelet medication thatunderwentcoilembolization.Total200mgAspirinand150mgClopidogrelwereadministeredatleast1hourbeforecoiling.SystemicheparinizationwasalsodoneafterinsertedGuidingsystem.Results:Among23cases,assistedtechniqueswereusedin14cases.Therewasnocasethatweinsertedintracranialstent.PostoperativeEVDorlumbardrainagewasdonein2and14cases,buttherewasnobleedingcomplication.Andtherewasnothromboticcomplizationcase.Conclusion: Preoperative antiplateletmedication leads to a low rate of thromboembolic complications andmayhavenoadverseeffectonbleedingcomplicartions.2-5)DelayedClopidogrelHyper-responseAfterNeuroendovascularTreatmentHidekiEndo,TatsuyaOgino,KoichiroShindo,YoheiMaruga,HirohikoNakamuraDepartmentofNeurosurgery,CenterforEndovascularNeurosurgery,NakamuraMemorialHospital,Sapporo,JapanBackgroundandPurpose:Antiplatelettherapyisveryimportantinendovasculartreatment.However,itisrecognizedthatthereare thepatientswith resistanceorhyper-response toantiplatelet agents. TheVerifyNowassaywas reported tobeuseful for identifying high or low on-treatment platelet reactivity. We report the cases of delayed clopidogrelhyper-responseafterneuroendovasculartreatment.Methods: The patientswith clopidogrel hyper-response after treatmentwere included in this study, among the patientswhounderwentneurointerventionalproceduresatNakamuraMemorialHospitalfromJune2014toJune2015.TheplateletfunctionwasmeasuredusingtheVerifyNowassay.Clopidogrelhyper-responsewasdefinedasP2Y12ReactionUnits(PRU)<60.Endovascularprocedures,durationofantiplateletagents,resultsoftheVerifyNowassay,andhemorrhagiceventswereretrospectivelyevaluated.Results:Elevenpatientswereenrolledinthisstudy.Weperformedcoilembolizationofintracranialaneurysmin6patients,in which stent-assisted coiling in 5 cases, and carotid artery stenting in 4 patients, and percutaneous transluminalangioplastyandstentingin1patient.Allpatientswerepremedicatedwithaspirinandclopidgrel,andgivenaftersuccessfulprocedures.Thedurationofclopidogreltherapybeforeprocedureswasaboutoneweekin8patients,and4-5weeksin2patients. One patient presenting subarachnoid hemorrhage was taken just before the procedures. Initial VerifyNowexaminationdemonstratednocaseswithclopidogrelhyper-response(PRU157.6±61.2).However,thefollow-upVerifyNowexaminationaftertreatmentdemonstratedclopidogrelhyper-response(PRU9.4±8.3).Atthefollow-upstudy,thedurationof clopidogrel therapy was 2-3 weeks in 9 patients, 1-2 months in 2 patients. Nine (81.8%) patients had confirmedhemorrhagicevents.ThevaluesofAspirinReactionUnitsshowednosignificantchangeduringtheobservationperiod.Conclusions:Wereported11casesofdelayedclopidogrelhyper-responseafterneuroendovascular treatment,whichwasassociatedwithhemorrhagiccomplication.Theantiplateleteffectappearstohavenotreachedaplateauafteroneweekoftakingclopidogrel.

2-6)Low-doseprasugrelpremedicationforendovasculartreatmentofintracranialaneurysmsHyun-SeungKang,WonSangCho,EunJinHa,YoungDaeCho,JeongEunKim, MoonHeeHanSeoulNationalUniversityHospital,SeoulNationalUniversityCollegeofMedicineBackgroundandPurpose:Theeffectivenessofantiplateletpremedicationiswidelyacceptedforendovasculartreatmentofintracranialaneurysms.Newergenerationantiplateletagentsmayusefulinthisclinicalsetting.Weinvestigatedaseriesofpatients taking low-dose prasugrel for endovascular treatment of aneurysms in terms of platelet function test,procedure-relatedcomplications,andclinicaloutcome.Materials andMethod: During the period between November 2014 andMay 2016, 260 patients (186 females and 74males; mean age, 57.9 ± 10.5 years) with 318 aneurysms underwent endovascular treatment for their intracranialaneurysms and low-dose (20 mg) prasugrel was given the day before endovascular treatment. Stent-supported coilembolization was performed in 94 aneurysms (29.6%) and Pipeline flow diverter was installed in 1. Response to theantiplateletmedicationwasmeasuredbytheVerifyNowassay.Eventsofproceduralbleedingandthromboembolism,andclinicaloutcomewereinvestigated.Results:VerifyNowassaydemonstratedmeanPRUvalueof130.2±80.2andmeanpercentageinhibitionof56.8±26.1%.WhenwesetthePRUof285asthecut-offvaluedeterminingtheresistancetoADPantagonists,6patients(2.3%)showedresistancetolow-doseprasugrelloading.Therewas1proceduralbleed(0.3%peraneurysm),withnoclinicalconsequence,andtherewasnoproceduralthromboembolicevent.Conclusion:Low-doseprasugrelpremedicationwaseffectiveinpreventingproceduralthromboembolismwithoutincreasedriskofbleeding.Resistancetolow-doseprasugrelloadingwasrare.

FeaturedSymposium “FlowdiverterinEastAsia”

S-1)EndovasculartherapyofintracranialaneurysmwithPipelineFlex:consecutive30casesinJuntendoUniversityHospitalKohsukeTeranishi1,KazumotoSuzuki1,SeisukeIseki1,KenjiYatomi1, SenshuNonaka3,MunetakaYamamoto1,HidenoriOishi1,2DepartmentofNeurosurgery,JuntendoUniversitySchoolofMedicine1DepartmentofNeuroendovascularTherapy,JuntendoUniversitySchoolofMedicice2DepartmentofNeurosurgery,JuntendoUrayasuHospital3,JapanBackground：Flow diverter stents have been widely used for large-giant intra cranial aneurysm throughout the world.PipelineFlexhasinitiallyapprovedinJapanforendovasculartherapysincelastyear. Objective：ToreportourinitialseriesofpatienttreatedwithPipelineFlexstentinJuntendoUniversityHospital.Methods：Allthedatawerecollectedfromconsecutive31aneurysm(20saccular,11fusiform)30patient(women28/age21-80years:mean62.3)treatedfromOctober2015toMay2016inJuntendoUniversityHospital,Japan.Results： Size and location of all the aneurysm were 10.0-27.1mm ( mean 16.5 ) in the anterior circulation ( due toindication for use in Japan ). Nine patients had symptom (oculomotor, abducens nerve palsy) before treatment. 20aneurysmsweretreatedwithsinglestent,11aneurysmsweretreatedwithmultiplestent.Eclipsesignwasobservedin16patientsimmediatelyafterstentplacement.Twocaseshadsymptomaticischemiceventoccurred.Conclusions：Pipeline flex play a great role for endovascular treatment of large and giant intra cranial aneurysm.Continuousdatacollectionshouldbeneeded.S-2)TreatmentofgiantMCAaneurysmusingflow-diverterwithpreservationofarterialbranch Jin-YoungJungM.D.,Ph,D.DepartmentofNeurosurgery,CerebrovascularCenter,Dong-EuiMedicalCenter,Busan,KoreaPurpose :Flow-diverting devices nowoffer a new treatment alternative for complex cerebral aneurysm such as giant orfusiform aneurysm.We present the results of a partially thrombosed giant aneurysm patients treatedwith the Pipelineembolizationdevice(PED),includingmid-termangiographyfollow-up. MaterialandMethods :A53-year-oldmalepatientpresentedwithacuteonsetof lefthemiparesis.Magnetic resonanceimaging (MRI) showedacutecerebral infarctionat rightbasalgangliaandPCA territory.ContrastenhancedMRI revealedpartially thrombosed giant aneurysm at right MCA trunk. ASA 100mg was given and 6months follow up CTA showedrecanalizationofthrombosedpartandgrowingofaneurysm.ASAadministrationwasdiscontinuedbuttheaneurysmwascontinuouslyincreased.Results:Pipelineembolizationdevice(PED)wasplacedatrightMCA.Almostimmediatelythebloodflowtotheaneurysmwasreduced,andthecompleteclosureoftheaneurysmoccurredwithoutproceduralcomplication.CompleteocclusionofaneurysmandpreservationofanadjacentsmallMCAbranchwasconfirmedat4monthsfollowupangiography.Conclusions:Flowdivertercanoccludethepartiallythrombosedgiantaneurysmwithpreservationofarterialbranch.S-3)ParentarteryreconstructionforlargeorgiantcerebralaneurysmsusingaTubridgeflowdiverter(PARAT):amulticenter,randomized,controlledclinicaltrialPARATinvestigatorsYuZhouDepartmentofNeurosurgery,ChanghaiHospital,SecondMilitaryMedicalUniversity,ChinaBackgroud: Treatment of large or giant aneurysms remains technically challenging, with a high complication andrecanalization rate. The Tubridge Flow Diverter (FD) may improve outcome of these aneurysms compared withconventionalstent-assistedcoilingwithcomparablesafety.

Methods :This study was a multicenter, randomized, controlled clinical trial conducted at twelve hospitals in China. Enrolled were adults with unruptured large/giant intracranial aneurysms. Using an online central randomization system, study collaborators randomly assigned participants (1:1) to receive either Enterprise stent-assisted coiling or Tubridge flow diverter implantation(with or without coils). The core laboratory evaluating pantients’ outcome were masked to the treatment allocation. Primary analysis was comparison of complete occlusion rate at 6-month follow-up between treatment and control group. The analysis was done in a modified intention-to-treat population using χ2 method, with multivariable logistic regression adjusted for unbalanced factors.

A sensitivity analysis was done to assess the effect of missing data. The trial was registered on the Chinese Clinical Trial Registry: ChiCTR-TRC-13003127, and is now closed. Finding: Finally, 185 patients were enrolled, 41 of them quitted the trial before procedure initiation. Overall, 82 patients received attempted Tubridge implantation, while 62 patients were primarily treated with stent assisted coiling. During the 6-month follow up, complete occlusion rate was75.34% (55/73) for Tubridge group, and 24.53% (13/53) for control group, and calculated common odds ratio was 9.4(95% [CI], 4.14 to 21.38). Sensitivity analyses and adjusted results also showed much better results for the Tubridge group.There were no significant differences in technique success rate, mortality or stroke related with target vessels, parent artery occlusion/stenosis, or general adverse events. Interpretation: Compared with conventional Enterprise stent assisted coiling, Tubridge flow diverter is an effective tool for the treatment of large or giant intracranial aneurysms with comparable safety.

Funding:MicroPortMedicalCompany(Shanghai,China);NationalScienceandTechnology;ShanghaiScienceandTechnologyCommissionS-4)Innovation of Endovascular Treatment Strategy for Large Carotid CavernousAneurysms - Safety and Efficacy of FlowDiverterShigeruMiyachi1,HiroyukiOnishi1,RyoHiramatsu1,TakashiIzumi2,NoriakiMatsubara2,ToshihikoKuroiwa11. Department of neurosurgery and Endovascular Neurosurgery, Osaka Medical College, Osaka, Japan 2. Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan ABSTRACTBackgroundandPurpose:Untilrecentlylargecarotidcavernousaneurysms(CCAs)havebeentreatedwithanendovascularapproachbystent-assistedcoiling(SAC)orparentarteryocclusion(PAO)withorwithoutanexternal-internalarterialbypass,particularly in cases with mass effect. The flow diverter (FD) is a promising device to promote aneurysm occlusion byrectifying blood flowwithout sacrificing theparent artery.We retrospectively compared the safety and efficacy of thesethreestrategiesforthetreatmentoflargeCCAs.Materialandmethods:BetweenJanuary2001andDecember2015,49patients(43women,6men;36–83yrsold,meanage63.4yrs)withlarge(max.dia.≥10mm)withabroad-necked,unrupturedCCAunderwentendovasculartreatmentatourinstitution. PAO, including proximal artery occlusion and internal trapping, was performed in 22 patients, SAC withneck-bridge stentswasperformed in 18patients, and flowdiversion (FD;with thedeploymentof thePipeline™embolicdevice) was done in nine patients. Safety and efficacy were assessed in all patients by periodic clinical and radiologicalexaminationsduringa6-monthfollow-up.Results: All 22 aneurysms treated with PAO disappeared immediately after treatment, but in the SAC group, completeocclusionwasobtainedinonly5ofthe18patients.AllaneurysmsintheFDgroupresultedinbodyfilling.WeencounteredoneintraoperativesymptomaticemboliccomplicationinthePAOgroup.Perioperativeipsilateraltemporaryischemiceventsoccurredinsixcases(PAO4,SAC2,FD0).Delayeddeteriorationornewonsetofcranialnervesymptomswasobservedin10cases (PAO 3, SAC 3, FD 4), almost all of which recovered within 3 months. During the 6-month follow-up, clinicalimprovementandastableasymptomaticstatewereobtainedinall43patients.InthePAOgroup,radiologically,alltreatedaneurysmsshowedadecreaseinsizeandnoevidenceofrecanalization,exceptforthreepatientswithmultipleuntreatedaneurysms which showed enlargement presumably due to postoperative hemodynamic changes. In the SAC group, 12aneurysmsshowedneckremnants,andmarkedrecanalizationoccurredinfourcases,twoofwhichrequiredretreatment.SixaneurysmsintheFDgroup,otherthanthethreewithasmallneckremnant,werecompletelyoccluded.Conclusion:TheFDprovidedexcellentfinalresults(particularlyinsymptomaticpatients),despitetransientworseningfromthe inherent acute inflammatory reaction after intra-aneurysmal thrombosis. In contrast, PAO involves risks of ischemiccomplicationsduetodecreasesincerebralperfusion,andSACispronetorisksofrecanalizationduetoanincompleteblockofinflowattheaneurysmalorifice.Thesetwoconventionaltreatmentsalsorequirelargeamountsofcoils.Althoughfurtherlong-termfollow-upisessential,fromacost-effectiveandtime-savingviewpoint,FDisarelativelysafeandreliablemethodforthetreatmentoflargeCCAs.S-5)Dynamic Volume Change of Thrombosed Giant Aneurysm after Flow-Diverting Stent Deployment: QuantitativeAssessmentbyComputedTomographicVolumetricImageWoongJaeLee,MD,1JunSooByun,MD,PhD,1JaeKyunKim,MD,1andTaekKyunNamMD,PhD2Departmentsof1Radiologyand2Neurosurgery,Chung-AngUniversityCollegeofMedicine,Seoul,RepublicofKorea

BackgroundandPurpose:PipelineEmbolizationDevice(PED)providesasafeandefficacioustreatmentforgiantintracranialaneurysms resulting high occlusion rate and low incidence of complication. However, incomplete obliteration orrecanalizationafterPEDmaypotentialforaneurysmgrowthandrupture.Angiographicfollow-upisnecessarytodeterminetheoptimaltreatmentthatleadstothehighestrateofobliterationandthebestclinicaloutcome.Wepresentacaseofthegiant thrombosed aneurysm treatedwith PED and follow-up assessment of residual sac change on CT volumetric image(CTVI).MaterialsandMethod:ConventionalBrainCTangiographywasperformedbeforeand1week,1,3,4,6,9,and15monthsafter PED deployment. CTVI including volume data (mm3 with HU) and 3D volume rendering images was obtained bysemi-automated methods on dedicated workstation (Extended BrillianceTM Workspace, version 4.5.2.). Dose-lengthproduct(DLP)ofeachCTAwas1269.2mGy-cmandcalculatedtotalpatienteffectiveradiationdose(ED)was11.2mSvperyear.Summaryofcase:Sixty-twoyear-oldfemalewithagiant,thrombosed,rightcavernousinternalcarotidarteryaneurysm(25mm in maximal diameter, 5.5 mm neck) was treated with endovascular obliteration using a single PED. A completionangiogram with Dyna CT showed appropriate position of the PED in relation to the aneurysm with decreased jet flow.Patientwaspremedicatedwithclopidogrel75mgandaspirin100mgdailyfor1weekpriortotheprocedureandfollowedafter PED. Preoperative aneurysm volume was measured 3883.8 mm3 (except of thrombosed portion, 100%) andprogressive shrinkagewas observed at 1week after PED (756.6mm3, 19.5%). However, aneurysm volumewas inverselyincreasedwithmorphologicchangeat1month(1385.4mm3,35.7%)andat3months(1565.7mm3,40.3%).Therewasnostent shiftingorendoleakonCTangiography.Wepresumedpatient’s coagulant statusmightbe thecauseofprogressiveaneurysmrecanalization.Wedecidedtochangeanti-coagulantoflowdoseaspirinaloneandfurtherfollow-up.Aneurysmsteadilydecreased involumeat4monthsof954.7mm3 (24.6%)andat6monthsof413.6mm3 (10.6%).OnthebasisofsequentialCTscanswithCTVI,wedecidedtofurtherfollow-upratherthanapplyadditionalPED.Residualsacwasfurtherdecreasedinvolumeat9months(461.8mm3,11.9%)andnearcompleteobliterationat15monthsof124.5mm3(3.2%).Patientwasuneventfulduringfollow-upperiod.Conclusion:QuantitativeassessmentofresidualsacchangeusingCTVIisfeasiblemethodfordetermineoptimaltreatmentinpatientofPED.S-6)Temporalchangesofintra-aneurysmalpressureafterplacementofPipelineEmbolizationDeviceusingelastase-inducedaneurysmmodelinrabbitsHideoChihara1,AkiraIshii2 KokuraMemorialHospital,DepartmentofNeurosurgery,Japan1KyotoUniversity,DepartmentofNeurosurgery,Japan2ABSTRACT:Pipeline Embolization Devise (PED, ev3, Irvine, California) has provided a new intervention capacity to treat cerebralaneurysmswith its diseased parent artery. The results of PED have encouraging,with large or giant achieving completeocclusionat12-monthfollow-up.Majorclinicalreportshavedescribedaslowprogressivethrombosisandgradualincreaseincompleteaneurysmobliterationrate.Despitepromisingearlyresults,somemiserablehemorrhagiccomplicationstoPEDhavebeenencountered. Delayedrupturemechanismshavevariouslyproposed.Oneofthemhasbeenachangeofintra-aneurysmalpressureafterPED implantation. Some case reports have described no change of intra-aneurysmal pressure in clinical case using apressurewireforcoronaryintervention.However,thosecaseshavealimitationonthelengthofthemeasurementtimeforclinicalcases. Wesought toevaluatemoredelayphase intra-aneurysmalpressureusingelastase-inducedaneurysmmodel in rabbits.5elastase-inducedaneurysms in rabbitswere treatedwithPED. Pressurewires (ComboWire,VolcanoCorporation, RanchoCordova,California)wereplacement inaneurysmswith jailing technique.Temporal changesof intra-aneurysmalpressureandparentarterypressureweremeasuredupto6hoursafterPEDimplantation.Angiographicevaluationwasperformedasappropriate. The mean aneurysms size was 7.31mm (4 to 14mm). 4 cases were used single device and one case wasperformed overlap stenting. In all cases, intra-aneurysmal pressureswere reduced on 6 hours after PED implantation incomparisonwiththeparentarterypressures.Furthermore,itwassuggestedthatparentarterypressureandmetaldensityof the aneurysm neck participated in advent period of pressure gradient. The present study demonstrated thatintra-aneurysmalpressurewasreducedbythePEDimplantation.

Session3 “CAS,Stroke”

3-1)ComprehensiveHybridStrategyforCarotidArteryStenosiswith“ToyamaCarotid8”rules.NaoyaKuwayama,NaokiAkioka,DainaKashiwazaki,SatosiKurodaDepartmentofNeurosurgery,UniversityofToyama,JapanWe report their preliminary results of carotid endarterectomy (CEA) and carotid artery stenting (CAS) for patients withcarotidarterystenosisaccordingtotheir“ToyamaCarotid8”rules. Thisprospectivestudyincludedtotal104patientswhounderwent CEA or CAS for carotid artery stenosis in our hospitals between March 2012 and January 2015. “ToyamaCarotid 8” rules primarily recommend CEA for symptomatic and CAS for asymptomatic lesions with crossover betweenthesetwomodalitiesforhightreatmentriskpatientsineachgroup. Asotherrulesof“ToyamaCarotid8”,monitoringofplateletfunctionsisquiteimportantpriortoCAS.InternalshuntingandnearinfraredspectroscopymonitoringareessentialinCEA.TemporarycardiacpacingismandatoryinCAS. ThechoiceofprotectiondeviceandstentdependsontheresultsofMR plaque imaging. Cerebral blood flow measurement should be always measured before and after CEA/CAS. No agelimitationisindicated.As the results, 52 CEA and 52 CAS were performed for 55 symptomatic and 49 asymptomatic lesions. The crossoverhappened in10(18%)of55symptomatic lesions(CEAtoCAS)and7(14%)of49asymptomatic lesions(CAStoCEA).The30-daymorbidity ratewas 1.9% in CEA and 1.9% in CAS group. Postoperative diffusion-weighted imaging detected freshischemiclesionsin5(10%)CEApatientsand9(18%)CASpatients. HyperperfusionsyndromeoccurredinoneCEApatient(1.0%).Therewerenomorbiditiesineachgroupduringperioperativeperiod.Establishmentofin-hospitalmanagementruleisusefulformedicalteamtosharetheiropinionsandimprovetheshort-termresultsofCEA/CASforcarotidarterystenosis.Furtherstudieswouldbewarrantedtoevaluatethelong-termoutcome.3-2)ExperienceofstagedangioplastyforcarotidarterystenosistoavoidhyperperfusionsyndromeKazutakaUchida,ShinichiYoshimura,ManabuShirakawa,KiyofumiYamada, JunkoKuroda,ToshinoriTakagiDepartmentofNeurosurgery,HyogoCollegeofMedicine,JapanObjective:Hyperperfusionsyndromeaftercarotidarterystenting(CAS)isacondition,whichmayleadtoseriouscomplicationssuchasintracranialhemorrhage.WehavepreviouslyreportedstagedangioplastyforavoidanceofhyperperfusionsyndromeafterCAS.Herewereportourtreatmentresultsanddiscusstheissuesregardingthisprocedure. Subjects:Thestudyincluded50casesofpatientsinwhompreoperativesinglephotonemissionCT(SPECT)showedseverelyimpairedcerebralbloodflow(CBF),forwhichSAPwassubsequentlyperformed.Theanalyzedsubjectsareasfollows:45malesand5females,or39symptomaticand11asymptomaticlesionswithmeanageof74±7.9yearsold. Methods:StagedangioplastywasperformedinpatientsinwhomSPECThadprovidedtheratiooftheCBFoftheaffectedtounaffectedhemisphere(asymmetryindex)of＜0.8withitscerebrovascularreactivityoflessthan10%.First,balloonangioplastywasperformedusinganundersized(2.0-2.5mm)balloon,andthenfinishedoncewhen2mmormoredilatationwasconfirmedbyintravascularultrasound.Subsequentapproximatelytwoweeksaftertheinitialtreatment,CASwasperformed.JustafterthatquantitativeSPECTwasconductedtoconfirmthepresenceorabsenceofradiologichyperperfusion.Inthecaseofinadequatedilatationorextensivedissection,stentplacementwasperformedjustaftertheinitialballoonangioplasty. Results:In46of50cases(92%),stagedangioplastywassuccessfullycompletedinavoidinghyperperfusionsyndrome,although3(6%)inadequatedilatationsand1(2%)vasculardissectionshiftedintoimmediateCAS.Amongthem,49cases(98%)showedfavorablecourseexceptforthatintracranialhemorrhagedevelopedinoneandischemiccomplicationoccurredinthefollowingdayofballoonangioplastyinanotherone.StagedangioplastycompletionsexhibitedhyperperfusionphenomenononSPECT. Conclusions:Thismethodwasrelativelysimpleprocedureinavoidinghyperperfusion.Buttheappropriatenessandoptimalconditionsofthemethodshouldbefurtherexaminedinthefuture. Keywords:stagedangioplasty,carotidarterystenosis,stenting,hyperperfusionsyndrome3-3)StagedCarotidArteryStentinginPatientswithSevereCarotidStenosis:MulticenterExperience.DongHyunYoo1,Hyun-SeungKang2,YoungDaeCho1,MoonHeeHan1,2,HongGeeRoh3,See-SungChoi4,SeJeongJeon41 Department of Radiology, Seoul National University Hospital, Seoul National University College of Medicine, 101Daehangno,Jongno-gu,Seoul,Korea2 Department of Neurosurgery, Seoul National University Hospital, Seoul National University College of Medicine, 101

Daehangno,Jongno-gu,Seoul,Korea3Department of Radiology, KonkukUniversity School ofMedicine, 120-1Neungdong-ro, Gwangjin-gu, Seoul, Republic ofKorea4DepartmentofRadiology,WonkwangUniversityHospital,895Muwang-Ro,Iksan,Jeonlabuk-do,RepublicofKoreaBackground and Purpose: Cerebral hyperperfusion syndrome (CHS) is uncommon but critical complication after carotidarterystenting(CAS).Intracranialhemorrhage(ICH),whichisthemostseveremanifestationofthesyndrome,mayleadtoprofoundmorbidityandmortality.DuetotheirreversibleanddevastatingoutcomeoftheICH,preventionofCHSisofvastimportancewhenperformingCAS.Thepurposeofthisstudywastoevaluatethesafetyandefficacyofstagedcarotidarterystenting(SCS)inpatientswithseverecarotidarterystenosis,particularlyinregardtopreventinghyperperfusionsyndrome.Materials andMethod: From January 2005 to February 2016, 53 patients with 55 severe carotid artery stenosis lesionunderwentSCS inthree institute.Theprocedureconsistedoftwosessions includingdelayedcarotidarterystenting(CAS)precededbyballoonangioplastyusing2to4mmundersizedballoon,andwereperformedatthediscretionoftheoperatorsconsidering clinical status and imaging studies of the patients. Postprocedural outcomes including immediate result,complication,andhyperperfusionsyndromewasretrospectivelyanalyzed.Results:Thestenosisdegreewasimprovedinallpatientsfollowingballoonangioplasty(90.±5.6%to70.5±12.9)anddelayedCAS(to16.1±14.1).ImmediatecomplicationwaspresentinthreepatientsafterballoonangioplastyandthreepatientsafterdelayedCAS,includingonesymptomaticthromboembolismaftereachprocedure.Headachewascomplainedby7patientsafter balloon angioplasty and10patients after delayedCAS,while onepatient developed focal neurologic deficit due tohyperperfusion.Therewasnoothermanifestationofhyperperfusionsyndromeincludingintracranialhemorrhage.Conclusion: SCS could be an effective treatment option for selected patients with severe carotid stenosis in preventinghyperperfusionsyndomeincludingintracranialhemorrhage. 3-4) Asinglecenterretrospectivestudyofstagedangioplasty forcerebralhyperperfusionhighriskgroupofcervicalcarotidarterystenosis. TakahiroMorita,MasayukiEzura,DaikiAburakawa,RyuzaburoKochi,Takashi Inoue,HirokiUchida,Tomoo Inoue,KensukeMurakami,ShinsukeSuzuki,HiroshiUenoharaSendaiMedicalCenter,DepartmentofNeurosurgery,Japan Cerebralhyperperfusionistheseriouscomplicationoftreatmentforcarotidarterystenosis.Treatmentisbeneficialforsevere cervical carotid artery stenosis, but severe carotid artery stenosis has the risk of post-operatice hyperperfusion.Recently,stagedangioplasty(SAP)isperformedforcerebralhyperperfusionhighriskgroupofcervicalcarotidarterystenosis.However,itsadaptationormethodisnotyetestablished. This time, we analyzed continuous 52 cases which was performed angioplasty for severe carotid artery stenosisaccompaniedbytheriskofcerebralhyperperfusionsyndrome(CHS)betweenJan2012toApr2016.WedefinedtheriskofCHS, (1) lateralityofcerebralbloodflow insinglephotonemissionCT (SPECT), (2) lateralityof thevisualizationofmiddlecerebral artery in MRA, and (3) delay of ipsilateral intracranial artery visualization in angiography. Hyperperfusion wasmeasuredbypost-operativeSPECT.Weexcludedthecasewhichwasdifficult toanalyzecorrect laterality inpre-operativeSPECT,MRAorangiographybecauseofbilateralseverecervicalcarotidarterystenosisorintracranialcarotidarterystenosis,andthecasewhichwasnotmeasuredhyperperfusionbySPECT. Inall52cases,SAPwasperformedfor19cases.33caseswereperformedcarotidarterystenting(CAS)inonestage.Postoperativehyperperfusionwasobserved4casesinSAPgroup(21%)and19casesinCASgroup(36%)(p=0.35).Theother,weperformedCAS infirststageandballoonangioplasty insecondstage inseveralcaseofSAPgroup,andall thesecaseshavefinishedsuccessfullytheoperation. WeconcludedwhichSAPisdefinitelyeffectiveforthepreventionofpostoperativehyperperfusion,andseveralmethodisconsideredforSAP,weusedependingonthecase. 3-5)Long-term outcome of endovascular recanalization in patients with Chronic Internal Carotid Artery occlusion: asingle-centerexperienceWanJieqing，SunWenhuaDepartmentofNeurosurgeryRenjiHospital,ShanghaiJiaotongUniversitySchoolofMedicine,ChinaAbstract: Objective: To analyze the feasibility, safety and long-term efficacy of Carotid Artery Stenting in patients with ChronicInternalCarotidArteryocclusion

Method:Theclinicaldataofpatientswithchronicinternalcarotidarteryocclusionunderwentendovascularrecanalizationat Renji Hospital affiliated to Shanghai Jiaotong University school of medical, from January 2008 to August 2015 wereanalyzedretrospectively.Theperioperativecomplicationsandclinicalefficacywereanalyzed.Results: 52 patients (47men, 5 women,mean age 59.04 years, range from 33 years to 82 years) were enrolled in thisresearch.Successfulrecanalizationwasachievedin45of52patients(86.5%).Intracranialhemorrhagewasoccurredinonepatient, without any sequelae. The average follow-up time was ( 22.1 ± 15.5 ) months, and the rate of follow-up was91.1%(41/45) . Only one patient suffered frequent TIA. Follow-up imaging revealed re-occlusion developed in only onepatient,restenosisdevelopedintwopatients(<70%).Conclusion: stent-assistedendovascular recanalizationshowsa long-termsatisfactory, safetyandefficacy inpatientswithchronicinternalarteryocclusion.KeyWords: endovascularrecanalization;chronicinternalarteryocclusion,stent,follow-up. 3-6)IntracranialAngioplastyandStentingforCrebralArtherosclerosis:Resultsof93ConsecutivePatientsJoonHuh,DaehyunHwang,Jeonghyunpark,InsooKim*,DalsooKim**, ChoonwoongHurh**DongtanSacredHeartHospital,HallymUniversity,KimpoUriHospital*MyungjiSaint Mary'sHospital,Seoul,KoreaBackgroundandPurpose:Strokeismostcommoncauseoflifethreateningneurologicaldiseaseandalsoitisleadingcauseof adult disability and third leading casuse of death. Intracranial atherosclerosis is 8 to 10% of all ischemic strokes andreportedpooroutcomeandhighrateofmorbidityandmortality. MaterialsandMethod:Weevaluated93consecutivepatients(agemean60,range34-80years,M:F=:)whounderwentintracranial stentingbetweenMarch2004andDecember2013.The locationof lesionwasMCA(n=25),distal ICA (n=31),Petro-cavernousICA(n=6),Basilarartery(n=3),Vertebralartery(n=28)andmeanstenosiswas72.8%Results:Theproceduralsuccessratewas93.5%.6casesareunabletoreachthetargetandperformedBalloonangioplasty.Therewereoverallthreecomplications(3.3%)withinperiodoffollowup(sixmonths);theseincludedoneminorstrokes(1.1%),andonedeaths(1.1%),onerestenosis(1.1%).ThekindofstentwasEndeavor (n=29),Vision(n=15),Cypher (n=14),Neuroform(n=10),Flexmaster(n=10),Arthospico(n=7),Tsunami(n=5),Guidant(n=3),Abbott(n=1),JMPTCA(n=1). Conclusion: In selected patients, endovascular revascularization of intracranial arteies with stent assisted angioplasty istechnically feasible, effective and safe. Randomized multicenter trial comparing angioplasty and stenting with medicalmanagementalonemustbeperformed.3-7)Acutestrokeshowingmajorintracranialvesselocclusion:characteristicsofcardioembolicsandatherosclerosisrelatedinsitustenosis/occlusionNobutakaHoriea,YoheiTateishib,MinoruMorikawac,YoichiMorofujia, KentaroHayashia,TsuyoshiIzumoa,AkiraTsujinob,IzumiNagataa,TakayukiMatsuoaaDepartments of Neurosurgery, Neurology and Strokologyb, and Radiologyc, Nagasaki University School of Medicine,Nagasaki,JapanAbstractAcute ischemic stroke showingmajor intracranial vessel occlusion is commonly due to cardioembolics or atherosclerosisrelatedinsitustenosis/occlusion,andimmediateidentificationofthesesubtypeisveryimportantforthetreatmentstrategy.Theaimofthisstudyistoclarifythedifferenceinclinicalpresentation,radiologicalfindings,neurologicaltemporalcourseandoutcomebetweentheseetiologies,whichhasnotbeenfullyevaluated.Consecutiveemergencypatientsshowingacuteischemic stroke were retrospectively reviewed. Among them, patients showing stroke with major intracranial vesselocclusion were analyzed focusing on clinical and radiological findings, and compared between cardioembolics andatherosclerosisrelatedinsitustenosis/occlusion.Of1053patients,80patientsshowedstrokewithacutemajorintracranialvessel occlusion (45 exhibited cardioembolics, and 35 exhibited atherosclerosis related in situ stenosis/occlusion).Interestingly,susceptibilityvesselsign(SVS)onT2*weightedMRangiographywashighlydetectedincardioembolics(80.0%)comparedwith atherosclerosis (in situ stenosis: 5.9%, chronic occlusion: 14.3%).Moreover, proximal intra-arterial signal(IAS)onarterialspinlabelinganddistalIASonfluidattenuatedinversionrecoverywaslowerydetectedinchronicocclusion(27.3% and 50.0%, respectively) compared with acute occlusion due to cardioembolics or in situ stenosis. Multivariateregression analysis showed that SVS is significantly related to cardioembolism (Adjusted OR: 21.68, P=0.004). Clinicalcharacteristics of acute stroke showing major intracranial vessel occlusion is different depending on the etiology,cardioembolics and atherosclerosis. SVS and proximal/distal IAS on MR imaging are useful to distinguish betweencardioembolicsandatheroscleroticrelatedinsitustenosis/occlusion.

KeyWords:Acutestroke,majorvesselocclusion,cardioembolics,atherosclerosis

Session4 “CCF,DAVF,AVM”

4-1)RetreatmentbyDetachableBalloonforRecurrentTraumaticCarotidCavernousFistulaeZHUQing,CHENAilin,CHENYanming,WANGZhongyong,XULiang,LANQingDepartmentofNeurosurgery,SecondAffiliatedHospitalofSoochowUniversity,Suzhou215004,China【Abstract】Objective To discuss the clinical efficacy and technique of retreatment by detachable balloon for recurrenttraumaticcarotidcavernousfistulae.MethodsTheclinicaldataof16patientspresentedasrecurrenceoftraumaticcarotidcavernous fistulae, who were retreated by detachable balloon, were analyzed retrospectively. All of them experiencedendovascular treatment by detachable balloon previously.Results 14 patientswere cured by detachable balloon(s), anddouble balloons technique was used in 6 of them during endovascular treatment. Another 2 patients were failed bydetachable balloon(s), and cured by detachable coils and Matas’ training respectively. Parent artery of all cases werepreservedwithoutischemicevents.ConclusionRetreatmentbyendovascularstrategieswaseffectiveandsafeforrecurrenttraumaticcarotidcavernousfistulaebasedonthecharacteristicsoflesions.Detachableballoon,doubleballoonstechniqueespecially,isarelativegoodchoiceforretreatmentofrecurrenttraumaticcarotidcavernousfistulae.【Keywords】traumaticcarotidcavernousfistulae;endovasculartreatment;detachablebaloon4-2)UsefulnessofDynaCTintheEndovascularTreatmentofDCCFZouchao,Liqiang,zhouyu,yangpf,huangqinghai,LiujianmingDepartmentofNeurosurgery,ChanghaiHospital,SecondMilitaryMedicalUniversity,ChinaBackground: Precise delineation of angioarchitecture and location of the fistula points is the key of Treatment of DirectCarotid-Cavernousfistula（DCCF）.SuperselectiveDSAinvariousprojectioncanevaluateitthroughhighdosesofcontrast,long examination times and substantial exposure to radiation.DynaCT provides more accurate information thanconventionalDSA.Objective:ToevaluatethismethodusingtreatmentofDCCFMaterialsandmethods:DynaCTreconstructionthroughRotationangiograghyfromdominantfeedingarteryin8patientscomparedwith2DDSAimages.Results:DynaCT demonstrate angioarchiechture of DCCF,relationships between the fistulous points and osseousstructures,the cavity of cavernous sinus which connects with ICA and its size and shape,also provide image from theaxial,coronal,sagittaloranyotherviews.Conclussion：DynaCTdigital angiogramsprovidea reliable visualizationof vessels and fineosseous structuresofDCCF,isquitehelpfulindecidingthetreatmentstrategy.4-3)ThefeasibilityofhybridoperationroomforthetreatmentofisolatedtypeduralarteriovenousfistulaHiroaki NEKI1), Shinya KOHYAMA1), Toshihiro OHTSUKA1), JunMATSUMURA1), Azusa YONEZAWA1), Aoto SHIBATA1), EisukeTSUKAGOSHI1),NahokoUEMIYA2),ShoichiroISHIHARA2),FumitakaYAMANE1)1)DepartmentofEndovascularNeurosurgery,StrokeCenter,SaitamaMedicalUniversityInternationalMedicalCenter,Japan2)DepartmentNeurosurgery,SaitamaSekishinkaihospital,JapanOBJECT: Isolatedtypeduralarteriovenousfistulas(DAVF)wereassociatedwithahighhemorrhagicrisk.DAVFismainlytreatedbytransarterialortransvenousembolization.SurgeryoracombinationwithsurgeryandembolizationisoccasionallyneededforDAVF treatment.Burrholeapproachanddirect sinuspuncturewithembolization is aneffectivemethod for isolatedtypeDAVF.However,theoperatorssometimessufferfromthedecisionofburrholelocationandsinuspunctureway.Thehybrid operation room is utilized for this burr hole approach in our institution.We report six cases treatedwith directtranssinusembolizationusingasingleburrholeapproachinhybridoperationroom. METHODS: Six patients underwent direct transsinus embolization of isolated DAVF in the hybrid operation room. Five cases aretransverse sinus DAVFs and one case is superior sagittal sinus DAVF. Three dimensional digital subtraction angiography(3DDSA)wasobtainedafter fixationofcraniumwith3-pins.Burrholepointwasdeterminedby3DDSA.Wetreatedwithpackingofcoilsandinjectionofn-butylcyanoacrylate(nBCA).RESULTS:

Hybrid operation room allowed accurate placement of the burr hole. Thesurgicalapproach consisted in a minimalexposureofthesinus.Wecouldchecktheburrholelocationandpuncturepointunderdigitalsubtractionangiographyatalltimes.Onlysingleburrholeandsmallskinincisionsufficedfordirecttranssinusembolizationforeachcase.CONCLUSION: DirecttranssinusembolizationofisolatedtypeDAVFisminimallyinvasiveandeffectivewhentransvenousembolizationisnotindicated.Hybridoperationroomisusefulinaccuratepositioningtheburrhole.4-4)EndovascularEmbolizationforComplexIntracranialDuralArteriovenousFistulaunderProtectionofIntra-SinusBalloonQianZheng,JiananLi,QiZhang,QiangLi,YiXu,JianminLiuDepartmentofNeurosurgery,ChanghaiHospital,SecondMilitaryMedicalUniversity,ChinaAbstract:Object: Endovascular embolization has been proven effective and safe option to treat most dural arteriovenousfistulas(DAVF). However, especially in some complex DAVF cases, the treatment goal isn’t only to guarantee completeocclusionof fistula,but toensure theunobstructedcerebral venousdrainage. Intra-sinusballoonprotection technique issuitableforcaseswhichaffectedsinusstillhavedrainagefunction.Weretrospectivelyreportourexperienceintheuseofintra-sinusballoonprotectionandclinicaloutcomeincomplexDAVFs.Methods: We performed a retrospective study of 13 patients (three females and ten males) with complex DAVF whounderwentendovasculartreatmentunderintra-sinusballoonprotectionatourinstitutefrom2012to2015,Wecollectedallclinical presenting symptoms, image features and follow-up outcomes to evaluate the effect of intra-sinus balloonprotectiontechnique.Results: All of the 13 patients belong to Cognard ⅡA+ⅡB, the location of DAVFs included sigmoid sinus(n=2), sinusconfluence(n=1),transversesinus(n=1),transverse-sigmoidsinus(n=4),superiorsagittalsinus(n=1)andmultiplefistula(n=4).Intra-sinusballoonprotectiontechniquewasused inallcasestoprotect thedrainagefunctionofsinus.Complete fistularocclusionwasdemonstratedby immediateangiograms in4patients,and total fistularocclusion in9patients. Immediatesymptomswereimprovedinallpatients,meanangiogramsfollow-upperiodof12patientswas8months.Conclusion: The intra-sinus balloon protection technique can avoid embolization of sinus to maintain normal drainagefunctionofsinus.4-5)Penetrable large shunting point in intracranial dural arteriovenous fistulas: providing alternative access route totransarterialintravenousembolizationDong-HyunShim,JieunRoh,YoungSooKim,SeungKugBaikDepartment of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine,Yangsan,KoreaObjective: Transvenous and transarterial embolization is the most common treatment method for the management ofintracranialduralarteriovenousfistulas(dAVFs).However,suchanapproachisnotalwaysfeasiblesuchasdAVFinvolvinganisolatedsinusandmultiplearterialfeeder.WepresentdAVFsthatweretreatedwithtransarterialintravenousembolizationoftheproximalvenousoutlet,aswellaspossiblecasespreviouslytreatedanotherrouteatoutfacility.Methods:Thisstudyincluded47patientswhohadundergoneendovasculartreatmentofthedAVF(4casesoftransarterialintravenous embolization). Every data including clinical, angiographic, andprocedural datawere retrospectively collectedfrommedicalchartsortheliteratureandrecordedonstandardizedformsbyaphysician.Theangiogramswereanalyzedbytwoindependentneurointerventionists.ThedAVFswereclassifiedaccordingtotheangiographictypeandvenousdrainagepattern.Results: In47patients,17 (36%)caseshavepossiblepenetrable largeshuntingpointwithdistalenlargement. In4cases,treatmentswereperformedviatransarterialintravenouscoilembolizationofproximalvenoussitebyusingthepenetrablelargeshuntingpoint; thoseresulted incompleteobliteration inallcases.Theaccessroute for12of the17caseswasthemiddlemeningealartery,for2wasthemeningohypophysealartery,andforeach1caseweredeeptemporalandoccipitalartery.Fiveofthe17caseshavemultiplepossiblepenetrablelargeshuntingpoint.Mostcases(94%)wererestrictivetype(maturetype)ofangiographicclassificationConclusion:Ifadistallyenlargedfeedingarteryisobservedamongthemultiplefeedingarteries,itsuggeststheexistenceofa large fistulaandmayserveasanaccessroute for transarterial intravenousembolization.Thepenetrable largeshuntingpoint with distal enlargement should not be overlooked as a potential access route for transarterial intravenousembolizationincaseswheretraditionalendovascularaccessislimited;thisapproachdoesnotcarrythesamerisksthataregenerallyassociatedwithpuretransarterialembolizationalongthispathway.Alsoitmayofferamoretreatmentoptionfor

neurointerventionist.4-6)EndovascularTreatmentoftheDAVFatthePetrousApexRegion LiuJiang1MaYong-jie2LiGui-lin2WangZhi-chao1ZhangHong-qi2 1Departmentofneurosurgery,BeijingHaidianHospital.Beijing,China. 2Departmentofneurosurgery,XuanWuHospital,CapitalMedicalUniversity,Beijing,China. Object:ToinvestigatetheendovasculartreatmentstrategyoftheDAVFatthepetrousapexregion. Methods:Clinicaldatesof9patientswithduralarteriovenousfistulaatthepetrousregionthatwerediagnosedandtreatedfromMay2013toMay2016inXuanWuhospitalandHaiDianhospital(8inXuanWuhospitaland1inHaiDianhospital).Allpatientshaveundertakenendovascularembolization.DSAandMRIwereperformedbeforeandaftertreatment. Results:Thereare6malesand3 femalesof the9patients.Their clinicalpresentationswereweaknessandnumbnessofextremities and sphincter disturbance, also including some cranial nerves disorders, the mean course of disease was 6months.Allofthepatientsunderwentembolization,andDSAfollow-uppostembolization，andallofthemgotanatomiccure，thedisordersrelievedordisappeared. Conclusion: Dural arteriovenous fistula at the petrous apex region is a rare kind of cerebral vascular malformation.Embolizationtreatmentshouldbethefirstchoiceiftheconditionofvesselsissuitableforintervention.4-7)TargetembolizationforrupturedcerebralAVMRyushiKondo1),HiroyukiKoizumi1),DaisukeYamamoto1),KazuhiroMiyasaka1),ToshihiroKumabe1),YasushiMatsumoto2)

1)Departmentofneurosurgery,KitasatoUniversity,Sagamihara,Japan2)Departmentofneuroendovasculartherapy,KohnanHospital,Sendai,JapanAbstractObjective: Patients with ruptured cerebral AVMs are at considerable risk of repeat haemorrhage, particularly whenassociated intranidalaneurysmsarepresent.Althoughthecompleteexclusionof theAVMisnecessary forpreventionofrebleeding, it issometimesdifficult toachievewhenthenidussit intheeloquentarea.WereporttwocasesofrupturedcerebralAVM,successfullytreatedbytargetembolizationforintranidalaneurysmsassociatedwithinitialbleeding.Casepresentation:Case1:A73-year-oldwomanpresentedwithsuddenheadacheandwastransferredtothehospital.CTdemonstratedsubarachnoidhaemorrhagesurroundingbrainstem.AngiographyshowedapontineAVMwithanintranidalaneurysmasthesourceofhaemorrhage.Therightshortcircumferentialarteryarisingfromthebasilararterywasfeedingthe nidus. The transarterial embolization (TAE) usingNBCAwas performed. The obliteration of intranidal aneurysm andpartial obliteration of the nidus was achieved. No rebleeding was observed for 9 months after the TAE. Case 2: A37-year-old man with left frontal AVM received the partial embolization using ONYX followed by the stereotacticradiosurgery. He had intracerebral haemorrhage 4 years after the first embolization and radiosurgery. He suffered 3haemorrhagicattacksintotalfor4months.AngiographyshowedaleftfrontalAVM.Theniduswithintranidalaneurysmastheoriginofhaemorrhagewaslocatedintheleftfrontallobeincludingthemotorcortex.ThetargetedembolizationoftheintranidalaneurysmbyusingNBCAwasperformedandtheobliterationoftheaneurysmwasachieved.Norebleedingwasobservedfor3monthsafterthetargetembolization.Conclusion: Target embolization for intranidal aneurysm associated with haemorrhage may reduce the risk of repeathaemorrhage.

Seeeion5 “Thrombectomy”

5-1)Parametric Digital Subtraction Angiography Imaging for Objective Evaluation of Endovascular Treatment inCerebrovascularDiseasesYina Wu DepartmentofNeurosurgery,ChanghaiHospital,SecondMilitaryMedicalUniversity,ChinaPURPOSE:To report the feasibilityofparametric color-codeddigital subtractionangiography (DSA) in complementing thetraditional,subjectivewayoftreatmentevaluationincerebrovasculardisease. METHODS: 18 consecutive patients with acute MCA occlusion and 70 patients with large intracranial aneurysms whoreceivedendovasculartreatmentwererecruitedfor investigation.Thechangesofthedelaytimeofdistaldevelopmentofparentartery,timetopeakflow,flowareaunderthecurveandmaximumslopeinaneurysmswereanalyzedbygeneratingatimedensitycurve.Thetargetdownstreamterritory(TDT)ofMCAandreferencepointatterminalinternalcarotidarteryofeachpatientwascontouredby5ratersindependentlyonthebasisofanteroposterior2-dimensionalDSA.TwoparametersofrelativemaximumdensityofTDT(rDensitymax)andpeaktimeinterval(ΔPT)betweenreferenceandTDTwereextractedby the use of parametric DSA analysis software. Interrater reliability was tested with intraclass correlation coefficients.Parameterswithsufficientinterraterreliabilityenteredvalidityevaluation.RESULTS: For the patientswith aneurysms, comparedwith the pre-operation results, the parent artery distal delay timedecreased (Mean 0.61s), the flow area under the curve in aneurysms (Relative value) and themaximum slope (Relativevalue) reduced 0.7 and 0.49, respectively. The rAUC/rMS/ATD are effective indices for better short-term result. ThetherapeuticstrategywaseffectivewhenrAUC>1.280±0.148,andwhenthevalueraiseto1.340±0.199,thelong-termresultwasmuchbetter.ThetherapeuticstrategywaseffectivewhenATD>0.583±0.174,andtheresultgotbetterwhenthevalueraiseto0.723±0.032.ForthepatientswithacuteMCAocclusion,theparameterrDensitymaxshowedastrongcorrelationwiththeAmericanSocietyof InterventionalandTherapeuticNeuroradiologycollateralgradingsystemscoreandmRSat3months,whereasΔPTaveragedidnot.Acut-offpointof0.224inrDensitymaxpredictedafavorableclinicaloutcomewithhighsensitivityandspecificity. CONCLUSIONS: The relative change of contrast density in the intracranial vessels on 2-dimensional DSA measured byparametricimagingtechniqueappearstobeasimpleandreliablemetricfortheassessmentofendovasculartreatmentforcerebrovasculardiseases.5-2)Interaction between the stent strut and thrombus as characterized by contrast-enhanced high-resolution cone-beamcomputedtomographyduringdeploymentoftheSolitairestentretriever TomoyukiTsumoto,MD,PhD;YuichiroTsurusaki,MD;SoTokunaga,MDDepartmentofNeuroendovascularSurgery,NationalKyushuMedicalCenter,ClinicalResearchInstitute,Fukuoka,JapanAbstractBackgroundandPurposeThe mechanism by which the stent retriever removes intraluminal thrombus from an occluded vessel has not been

discussed in humans. This study performed contrast-enhanced high-resolution cone-beam computed tomography(CE-HRCBCT) during deployment of the stent retriever to observe the interaction between the strut and intraluminalthrombusintraoperatively.Wealsodiscussthemechanismbywhichthethrombusisretrieved.MaterialsandMethodsInelevenpatients,mechanicalthrombectomywasperformedwiththeSolitairestentretriever.Thepresenceorabsenceof

flow restoration (FR) was evaluated immediately and at least 5 minutes after deployment. Stent retriever findings onCE-HRCBCTwasdividedintotwogroups:(1)completeexpansion,and(2)incompleteexpansion.ResultsFR was observed in all eleven cases (100%) immediately after deployment of the Solitaire stent retriever. Complete

expansion was observed only in one case, and incomplete expansion was observed in ten cases. The thrombus wasobservedmainlynearandoutofthestrutofastentretrieverinCE-HRCBCT.LossofFRwasrecognizedonlyinoneofelevencases.Regardless,successfulrecanalizationwasachievedonlywiththestentretrieverinnineofelevencases.ConclusionCE-HRCBCTshowed that theSolitaire stent retriever rarelyexpanded fullyand thrombuswasmainlynearandoutof thestrut. Itmaynotbenecessarytowaita longtimetoallowthestenttoexpandfully intothethrombusbecausethemaincapturemechanismseemstobeengagementoftheclotbetweenthecrossingsofthestrutsoftheSolitaire.5-3)

HistologicalexaminationofvasculardamagecausedbystentretrieverthrombectomydevicesDaisukeArai,AkiraIshii,HideoChihara,HiroyukiIkeda,SusumuMiyamotoDepartmentofNeurosurgery,KyotoUniversityGraduateSchoolofMedicine,Kyoto,JapanBackgroundandObjectivesAlthoughtherecently-marketedstent retriever thrombectomydeviceshavedemonstratedahighrecanalizationrateandfavourableclinicaloutcomes,casesoflatevascularstenosisandvascularocclusionhavealsobeenreported.Inthepresentstudy, the SolitaireTM Flow Restoration System and TrevoTM Retrieverwere used in a histopathological comparison ofvascularinjuriescausedbystentretrieverthrombectomydevices.MethodsRabbit carotidarterieswereused in theexperimentswith stent retriever thrombectomydevices.Carotidartery sampleswereharvestedeitheroneortwoweekspostoperativelyforhistologicalexamination.ResultsWiththeSolitaireFR4mm,intimalandmedialthickeningwasobservedoneweekpostoperatively,andprogressionofintimalthickening was observed two weeks postoperatively. The extent of intimal thickening tended to be greater with theSolitaireFR6mmthanwith theSolitaireFR4mm,but thisdifferencewasnot significant.Compared to theSolitaireFR4mm,theTrevohadasignificantlysmallerareaofintimalthickening.ConclusionsAlthoughtherearesomedifferencesamongdevices, results fromthisstudy indicatedthatstentretrieverthrombectomydevicesinducevasculardamagethatextendstothemediallayer.5-4)RelayBalloonTechniqueforRecanalizationofAcuteSymptomaticProximalICAocclusionSangHunLee,MD;DongGeunLee,MD;SunU.Kwon,MD;DeokHeeLee,MDDepartmentsofRadiologyandNeurology,AsanMedicalCenter,UniversityofUlsanCollegeofMedicine,Seoul,RepublicofKoreaBackgroundandPurpose:Endovascularrecanalizationofanacutesymptomaticocclusionoftheproximal internalcarotidartery (ICA), due to underlying atherosclerotic stenosis, could be technically challenging due to possible thromboticcomponent.This isespeciallytruewhenthere isnotenoughofa landingzoneforaballoon-guidedcatheter(BGC)atthebulbportion.Thepurposeofthisstudyistoreviewthesafetyandeffectivenessofanovel"relayballoontechnique"whichwasdevisedtotopreventanythromboembolismduringangioplastyandstenting.Materials andMethod: Endovascular recanalizationwith the ‘relay-balloon technique’was attempted in 10 consecutivepatientswithacutesymptomaticproximalICAocclusionsfromFebruary2013toFebruary2015.Thedistalcommoncarotidartery (CCA) was occluded with a BGC during balloon dilatation with an angioplasty catheter (APC) for the underlyingproximalICAstenosis.ThentheinflatedAPCwasrepositionedalittleupwardassuringflowarrestsothattheBGCcouldberepositionedintothebulbportionforfurtherICAflowarrestandaspirationoftheoccludedICAafterremovingthedeflatedAPC. After full recanalization of the ICA and elimination of any combined distal embolic lesions, the proximal ICA wasstentedwhile theBGCwas removed (Figure).Weanalyzed the technical success rateand reviewed theearly clinical andangiographicoutcomes.Results: The time required for the procedure ranged from 25 to 127 minutes (mean, 80 minutes). Successfulrevascularizationwasachievedinallpatients(thrombolysisincerebralinfarction[TICI]2a/band3).Post-proceduralinfarctextensionoccurredinonepatient.Despiteoftheextensionofinfarction,theincrementoftheNIHSSwasnotobserved.Themean NIHSS score at dischargewas 3.55 (range 0–18) and themeanmodified Rankin Scale score at threemonthswas1±1.67(range0–6).Conclusion:TherelayballoontechniquecanbesafelyandeffectivelyappliedtotheendovascularrevascularizationofacutesymptomaticproximalICAocclusions,whichotherwiseseemtohavehighriskofdistalthromboembolismduetoinsufficientlandingzonefortheballoonguidingcatheter.5-5)RecentourimprovementofendovascularrecanalizationbystentretrieverformiddlecerebralarteryocclusionYuchi Matsui, Hirotoshi Imamura, Syoichi Tani, Hidemitsu Adachi, So Tokunaga, Takayuki Funatsu, Mikita Beppu, KeitaSuzuki,HiromasaAdachi,TomohiroOkuda,SyuheiKawabata,YasunoriYoshida,RyoAkiyama,KazuhumiHoriuchi,KenichiTodo,TomoyukiKono,TakuHoshi,NobuyukiSakaiNeurosurgery,NeurologyandComprehensiveStrokeCenter,KobeCityMedicalCenterGeneralHospital,Japan

【Purpose】Sincefivestudiesshowedefficacyofendovasculartreatment(EVT)foracuteischemicstroke(AIS)in2015,wehavebeenpaidattentiontoshortentimetorecanalizationasafactorrelatedtotreatmentresult.Wereviewedin-hospitalprotocol;MRIskipsbyaninitialimageevaluationincaseofwithin4.5hoursfromonsettoadmissiontostartEVTfasterandreformofsenseofshortentimetoallmedicalstuff.WeexaminedtheinfluenceofshorteningofrecanalizationtimegaveintheresultsofendovasculartreatmentforAIS.【Materials andmethods】Since July, 2013 to January, 2016,weexperienced23 cases ofmiddle cerebral artery (MCA)occlusion,admittedwithin4.5hoursfromonsetandtreatedbystentretriever.Weexaminedtreatmentresultsbydividedintofirsthalfgroupbeforeprotocolreviewandthelatterperiodgroup.WeexcludedcasesofmodifiedRankinScale(mRS)is3ormorebeforeonset,occlusionvesselisexceptMCA,andso-calledDrip-shiptreatment.【Results】First groupare12 cases and latter groupare11 cases. The average age is 78.3 yearold and77.4 years old,respectively.Occlusionportion(M1proximal:M1distal:M2)are4:4:4and2:4:5,respectively.MRIperformedbeforeEVTinall cases of first group and 5 of 11 (45%) in latter group. We do not recognize the significant difference in a ratio ofintravenousrt-PApriortoEVT,58%infirstgroupand82%inlattergroup,(p=0.240).Averagetimefromonsettoadmissionis66.9minutesand65.4minutes(p=0.992).Averagetimefromadmissiontopunctureissignificantlyshortinlattergroup(97.1minutes in firstgroup,52.6minutes in lattergroup,p<0.05).The ratioofmRS0-2at90dayswas tend tobetter inlattergroup(33.3%infirstroup,72.7$inlattergroup72.7%,p=0.063).【Conclusion】ResultsofEVTusingstentretrieverforMCAocclusionwithin4.5hoursfromonsettoadmissionimprovedbyshorteningtimetorecanalization. 5-6) TheimpactoftortuosityofthetargetvesselsonintracranialhemorrhageafteracutethrombectomyManabuShirakawa,ShinichiYoshimura,KazutakaUchida,SeigoShindoDepartmentofNeurosurgery,HyogoCollegeofMedicine,JapanPurpose: The purpose of this study was to elucidate the effect of tortuosity of the target vessel on the intracranialhemorrhagiccomplication.MaterialsandMethods:Atotalof75consecutivepatientswhounderwentmechanicalthrombectomyforacutelargevesselocclusionbetweenSep.in2013andJunein2015wereincluded.Thepatientswereclassifiedintotwogroups;hemorrhagicgroupandnon-hemorrhagicgroup,basedonthefindingsonheadCTperformed12to24hoursaftertheprocedure.Vesseltortuositywas assessedbymeasuring thedistancebetween thehighest and lowest points ofM1 in themiddle cerebralartery(MCA). Results:Among75patients,27(36%)wereclassifiedintohemorrhagicgroupand44(64%)wereinnon-hemorrhagicgroup.Baselinecharacteristicswerenosignificantdifferenceinbothgroups.ThedistanceofhighestandlowestpointsinM1wassignificantly larger inhemorrhagicgroupcomparedtonon-hemorrhagicgroup(8.8vs7.0,p=0.01).Thepercentageofthefavorableoutcome(modifiedRankinScale0-2)ondischargewaslessinhemorrhagicgroupcomparedtonon-hemorrhagicgroup(19%vs53%,p=0.003).Conclusion: The results obtained in the present study indicated that the incidence of intracranial hemorrhagic afterthrombectomywassignificantlycorrelatedwithtortuosityofthetargetvessel.