- Email: [email protected]
Preliminary experience with 4 kinds of combined transpetrosal approach for intracranial tumours
Tuesday, 8 July 1997 service in favor of anintranasalprocedure. The advantages are: short route to the sella, bettercosmethicresultsand lesspathogenicflora. At thebeginning, we usedcollumelartransfixatingincisionandcartilaginous-osseus septal dissection.Since1993, an ingeniousmodificationto theprocedurewas introduced. Topicalvasoconstrictoragentisinstilledin onenostril,usuallythe left. A mucoperichondralflap iscreatedby aseptalincisionat thecartilaginous-osseus junction.Bilateraldissectionof themucosaexposestheosseusseptumandthe sphenoidalrostrum.Injuryto the septal branchof thepterygo-palatinearteryis avoidedbysubperiostealdissection.The operativeexposureof thesphenoidal sinus is as wide as the sublabialapproach. The anterior wall of the sphenoid sinus isremoved to expose the floor of the sella. At the end of the operation, the mucoperichondralflap is turned tocoverthe reconstructedsellafloor. The middleturbinateis removed and used as a graft for sella reconstructionto reinforceclosure.The nasalcavityispacked withtetracyclinimpregnatedgauze. This seriesincludes32 pituitaryadenomas,two CSFleaks, threenon-adenoma selar tumorsand one chiasmapexyfor emptysellasyndrome.
IP-3-362I
Microsurgicalanatomy of theposteriorregion of the limbicsystem seen by the supratentorial-infraoccipital approach
S. Gusmao, R.L. Silveira,G. Cabral, A. Andrade. HospitalMadre Teresa, Belo Horizonte,Brazil Introduction:Accordingto Yasargil (1984), "thesubarachnoidalcistems are theroadmapsfor themicroneurosurgeon". The supratentorial-infraoccipital approach providesan avenueto theposteriorregion of the limbicsystem. It is carriedoutthrougha naturalspacebetweentheinferomedialpartof theocciptal lobeand thetentorium.The purposeof this work is to studythe posteriorregion of the limbicsystemthat can be visualizedby thisapproach. Material and Methods: Amicrosurgicalanatomystudy wasundertakenin approachwasperformed 10 cadavericheads. The supratentoral-infraoccipital as thetechniqueproposedby Clark WK(1987). Results: Theparahippocampalgyrusextendsfromtheuncusto theisthmus of thecingulategyrus andcontinuesto themedial occipitotemporalgyrus. Its posteriorpart extendsupwardand medially,and isdirectedto thespleniumof the corpuscallosum,as afolding,theisthmusof thecingulategyrus,whichjoins theparahippocampalandcingulategyri.Theisthmusextendsobliquelyupward and posteriorand itsconcave partpasses around thespleniumof the corpus callosum.In theretrothalamiccistern,the posteriorpart of thepulvinarof the thalamusis located anterolateralto the triangle formed by the quadrigeminal plate and thespleniumof the corpuscallosum,which are in themidline,and theisthmusof thecingulategyrus,posterolateralto theselasttwostructures.In the ambient andquadrigeminalcisternswe canidentifythe posteriorcerebral arteryand itsbranches,and the basilarvein of Rosenthalandinternaloccipital veins. Conclusions:The posteriorregionof the limbic systemcan beexposedby thesupratentorial-infraoccipital approachwithouttransectingthecortexandthe ventricles.
IP-3-363!
Temporobasal approach to lesionsin and/or near the temporal horn andtrigone
M. Nishikawa,M. Matsumoto,T. Mizutami, R. Ishizaki,H. Yoneda, A. Kaneko. Departmentof Neurosurgery,KokuraMemorialHospital,Kitakyushu,Japan temporalhornandtrigone,especially Introduction:Lesionsin and/ornearthe of thedominanthemisphere, are difficult toremove, because of theirdepth, injury toWemicke's area and the opticradiation. We use the lateral basal approachto lesionsof this area and havehad goodresults.We are reporting thismethodand ourexperiences. Clinical Material and Methods: Five AVMs, 2 cavemomas, and 1 brain tumor wereoperated on in ourdepartmentsince 1993 with thismethod. The operativemethodis asfollows;a temporalosteoplasticcraniotomyis madewith a lateralpositionloweringvertex down. It isimportantto remove thetemporal bonedeepto the middlefossa.After openingthe dura,the baseof the temporal lobeisexposedbyretractingslightlythe lateralpartof it andthe occipitotemporal sulcus, which is located about 2 cm inside of the lateral part of thetemporal lobe, isopened. Enteringthe sulcus,medialto the opticradiation,theventricleis easilyreached. Once thesurgeonis in thetemporalhorn,anatomicorientation becomeseasier. In casesofAVM, the anteriorchoroidalartery, whichinvariably feeds the AVM,canbe followedto the lesion.Tumorsandcavernomascan be seenthroughthe ependyma. Results: Onepatientwith recurrentAVMsufferedfromaquadranthemianopsia and another patient with AVM mild paresthesia.All otherpatientsshowed noneurologicaldeficits. Conclusion:The lateralbasalapproachis averyusefulmethodforexcision of lesionsin area.
Technology - SurgicalApproaches
IP-3-364!
S153
The combinedsubtemporal-suboccipital approach. A modifiedsurgical access to the clivusand the petrousapex
AbolghassemSepehrnia, UlrichKnopp. NeurosurgicalDept., Universityof LObeck, Germany Introduction:The surgicalaccess to the clivus and the petrousapex is still a challenge.A combinedapproachis best fitted to tumors locatedin the middle and posteriorcranialfossa. The approachdescribedin our series iscentered on the petrous bone andrequires an extensive petrous-boneresection. An osteoplasticbone-flapis no longernecessary. Methods: We report on the last fiveconsecutivepatients, whounderwent surgeryusingthefollowingtechnique:The petrousbone is drilledawayanterior unroofed.Forexposureof the middlecranial to thesigmoidsinus, the sinus is fossa thepetrous boneshould be resected down to the roof of the external meatus. Results: Thesurgicalaccessasdescribedaboveprovidesa wideoperative fieldwithpreservationofimportantintracranialstructuresas showninour series. Discussion and Conclusion: This modifiedapproachminimizesthe cerestructurescan be bellarandtemporalloberetraction.The neural and vascular preservedunder directvision to thetumor. The blood supply is interruptedin thebeginningof theoperation.
IP-3-36SI
A modified surgicaltechniquefor thepresigmoid approach:Osteoplastic mastoidectomy followedby single-flaptemporo-suboccipital craniotomy
Yutaka Sawamura, TsutomuKato, HiroshiAbe.Departmentof Neurosurgery, HokkaidoUniversitySchoolofMedicine, Sapporo,Japan Objective: Thecombinedsupra-andinfra-temporaltranspetrosalapproach,the presigmoidapproach,requiresa temporalsuboccipitalcraniotomyand unroofing of the duralsinuseswithmastoidectomy.Toreduce the bone defect in the mastoidareaandtodecreasethe riskofinjuringthe duralsinuses,we describe a modifiedsurgicaltechnique,and inaddition,demonstratethe usefulnessof fibringlue inmastoidbonereconstruction. Methods:Beforethecraniotomy,a surfacemastoidectomywas carried out using a rongeur to preserve bonefragments for laterreconstructionof the mastoid process. Through the cavityresultingfrom themastoidectomy,the dural sinuses were dissectedfrom their bony grooves.A single-flaptemporosuboccipitalcraniotomywas thenperformed.Uponclosure,after fixation of a temporo-occipitalbone flap, amixtureof the bone chips and human allogenic fibrin glue withantibioticwas molded and placed to fill bony defects in the mastoidprocess. Results: Ninepatientswereevaluatedafterfor morethana year. Therewere nocomplicationsdirectlyrelatedto theosteoplasticmastoidectomy.Neitherosteomyelitisnormastoiditisoccurred.Follow-upthree-dimensionalCT revealed that seven of ninereconstructionsof themastoidprocessremained sufficient; but in two cases the bone chips were absorbedwithin eight months after the surgery. Conclusion:Osteoplasticmastoidectomyfollowed by en-bloc temporooccipitalcraniotomyenables minimizationof the bone defect in themastoid area. In addition,beginningwith amastoidectomyfacilitatessafedissectionof the outerduracoveringthesinusesandadherentto the bonygroove.
I P-3-366I
Preliminaryexperience with 4 kinds of combined transpetrosalapproach forintracranialt umours
ShenJiankang,Uu Chengji,Hu Bingchenet al. Departmentof Neurosurgery, RuijinHospital,ShanghaiSecondMedicalUniversity,Shanghai, PR China Seventy-twocases ofintracranialtumor, most of which werecerebellopontine angletumors, were operated on by 4 kinds ofcombined transpetrosalapproach. Of them, 34 cases were acoustic neuroma and wereoperated on by a translabyrinthinetranstentorialapproach. Seventeen cases werecerebellopontineangletumorincludingmeningioma,cholesteatoma,glioma,chordoma, neuroma except foracousticneuroma, which wereremoved via a transmastoid-transtentorial approach.Threecasesweretrigeminalneuromaofhourglass type,6 caseswerechordomaorcholesteatomaand 2 casesweremeningioma oftentorialedge, whichwereremovedby a combinedtransmastoid-transtentorialandsubtemporalapproach.Seven casesofmeningiomaincerebellopontine angleor clivusand 3 cases of chordomain clivus were treatedby caombined transmastoid-transtentorial and retrosigmoidapproach.Totalremoval of tumor was achieved in 65 cases(90.6%). Sixty-fourcases had goodpostoperative outcome,7 caseshad poor resultand one case died. Main postoperativecomplicationin relationto theapproach is CSF leakage in 3 patients, which was cured byreoperativerepair in one and by lumbar CSF drainage in other two. Advantagesof thecombinedtranspetrosalapproachincludea wideroperative indication,wideningtheoperativefield,shorteningoperativetime anddecreas-
5154
Tuesday, 8 July 1997
Technology- Miscellaneous
ing postoperativecomplications , 50 the extended trarfspetrosalapproach is very usefulfor removalof cranial base tumor in middle orlandposteriorfossa.
rather cheapmaterial, easily suitable to cover a defect, but causes frequent inflammatoryreactionaroundtheimplant. In the last 2 yearswe tried to usea newalloplastic material"Os proge l ~ that iscomposedof Hydrohyapatite , boneprotein derived gel, and water, and that is P-3-367! Reconstructionof skull defects with homograftskull not only areplacingmaterialbut also abiologicalactivesubstance,by inducing bone new boneformation,This has beendemonstratedin many cases treated by dentalandmaxillo-facialsurgeons. ZhiyongVan, Shugan Zhu,HongweiHe. DepartmentofNeurosurgery,the With thismaterial we performed7 cranialreconstructionsusing either OsAffiliatedHospitalof ShandongMedical University,Jinan, PR China titanium mesh andlorplate progel alone for smaller defects, Osprogelwith or Six rabbitsunderwentreconstructionof skull defect with homograftskull bone. curvatureand to assure a proper in largersizes, in order to maintain the right 01 skull defect. The There were six control animals that did not have repair guide for boneregrowth. The best results were obtained in medium sized deresultsofcompressiontest and thepathologicalmorphologyindicate: (1) Skull fects (about15--20 sq.cm) usingOsprogelwith a support of titanium net fixed bonehomografts with the contour of therroundin su g skull boneafter 8months; with microscrews to the border of the craniectomy . Good results were also (2) The homograftshave no significant differencescomparedwithnormalskull; obtained in those cases where taitanium mesh was included in a sheet of (3) The formationof new bone does not affect the function of the dura mater Osproge1 (·Osprotitantex "~) . When correctly used, that meansthat Osprogelis or the brain. There were 7 patients with skull bone homogralts.The follow-up kept in contact with healthy cancellousbone. After six monthsthe defectswere periodsof the patientswere from 6 to 18 months. The reconstructedsites have completelyfilledbynewlyformed bone, as seen on 3D reconstructedCT scans. compressedand are a normalappearancewithoutdepression, are solid when analogousto the normalskullbone. No focalfluid collectionorinfectionoccurred afteroperation. Nocomplicationsoraggrevationof the priorsymptomsoccurred I P-3-370 I The use ofhydroxyapatiteceramics in the afterreconstruction . reconstructionof surgicalskulldefectsfollowinga
I
frontotemporalapproach YojiNode, AkiraTeramoto. Departmentof Neurosu rgery, Nippon Medical SchoolTokyo, Japan Purpose: Large portions of the supraorbitalmargin, the cheek bone, and the sphenoidbone arecommonlyremoved as part offrontotemporalsurgery for deepcerebral aneurysmsand basaltumors. In most cases, it is not possible to Tuesday, 8 JUly 1997 14:00-16:15 retain the original form of the bone flap, and fragments of bone are employed to restorethe shape when closing the skull. The resin used brings with it the risk P-3 Technology - Miscellaneous autogenousbone is insufficient for restoration. The of infection, and the use of authorsreporttheir experimentswith hydroxyappaiteceramics(HAC)as an aid problems,and its use inreplacingmissing bone in the locations to solving these mentionedabove. P-3-368I New hardware andsoftwaretoolsto makefunctional Method: Nine patients (four males, five females, mean age - 54 years) imaging a reliablepreoperativeprocedure were treated, 6 forcerebral aneurysms,and three for basaltumors. HAC was employedto replace missingbone in the supraorbitalmargin,the cheek bone, T. Hoell,F. Oltmanns, A. Schilling, M. Brock. Dept. ofNeurosurgery.Benjamin and the sphenoid, torestoreskull shape. The HAC consistsof an inner portion FranklinUniversity Hospital, Berlin, Germany forming the inside of the skull, and an outer portion (the skull surface). The Introduction:The most important application of functional imaging,particularly externalportion is formedintothin, triangularpieces, and usedas the base onto is the preoperativeidentificationof eloquentareasof the cortex. This technique whichthe inner portion, also in the form of thin triangularpieces, is attached. hasbecomean adequate researchtoolbutstill lacksthe highdegreeof reliability Conclusions:(1) The amount of missing bone differed between patients. necessaryto identityfunctionalareasrequiredforsurgicalplanning. Problems However, astrimmingis accomplishedcomparatively easily, the amount reare the transmission of cognitive optical stimuli to the patient, the finding of quired for each defect may be adjusted for each patient and no particular an adequate sensory stimulus that can be used for fMRI and perioperative problems were experienced. (2) No post-operative infections were noted. (3) investigation of sensoryevokedpotentialsin the same manner. consideredsatisfactory . Cosmeticbenefits are designedfor the transMethods and Techniques: A fiberoptic systemwas mission of optical stimuli. An appropriatehead set wasintroducedto reduce MR noise and to apply acoustic stimuli. A patent was filed for a pneumatic P-3-371 An alternativetechnologyfor Identicalreplicationin systemfor touchingthe skin with precisionof a less than 4 ms, whichis precise the multiple fractured skull enough to apply identical stimuli for pre- and perioperative 5EP testing. SoftE. Schultke,J, Hampl, J. Koy, L. Jatzwauk ' , G. 5chackert.Dept. of opticalstimuli and a set ware wasdevelopedto activate the motor cortex via Neurosurgery.TU Dresden,Dresden, Germany, , Dept. of Microb iology, TU of newparadigmswas tested for activation of different componentsof speech Dresden, Dresden, Germany functions. Results: The optical activation system was used153 in patients.Reliable Traditionallythe reconstructionof major bone defects in the skull with multiple functional images could be obtained in 85% of all cases. In 12 cases the fracturesis performedusingosteocementumafterregressionof initial cerebral functionalimages were used to decide upon the best neurosurgicalapproach. oedema has occurred. As has been shown before (Koy, unpublisheddata) in Postoperativecognitive investigation revealed a successfulplanningstrategy. only10 out of30 patientswhounderwentthisprocedurethe cosmeticresultand All softwarecomponentshave been usedsuccessfullyunderclinical conditions thefitof theimplantrangedbetweengoodandvery good.whilstin the remaining componentsare still under investigation in casesthe mostcommonfaults were gaps and steps betweenplastic and skull. for more than one year. The other To avoid these problems we have developed an easy method based on a ongoingresearch. Conclusion: The introductionof new hard- andsoftware toolsimproved plaster-castproceedingusingsterilizedgypsum, The method allows identical functionalimagingto a level,whichallowsa consolidatedpreoperativedecision reconstructionof the original part of the skull and implies the need for an makingbased on thefunctionalimagesofindividualpatients. acceptable cosmeticoutcome. As the implant can be shaped under sterile conditionsat any time beforethe beginningof actualsurgeryanother advantage is the savingof time. P-3-369! Cranioplastieswith thealloplasticmaterial The first requirement for the production of identical copies in skull defects "Osprogel" ®; Differentmodalitiesof applicationand is the availability of all parts of the original calvaria, only an extremely minor results fragmentmay be omitted. The secondrequirementis the availabilityof sterilized gypsum (dubble hot-air sterilization) so as to avoid any interruptionsin the AlfredoPompili, Carmine M. Carapella FabrizioCaroli, , FabioCattani, sterilizationprocedure. After assembling thefragmentsin the original shape MaurizioFontana, GiancarloSestili 'EmanueleOcchipinti , . Div. of of the skull a gypsum matrix ind uding both a convex and a concave cast Neurosurgery.Rome, Italy, , Diagnostic Radiology Ist/turoReginaElena, Rome, is moulded. Afterhardening the implant is modeled in this matrix using the Italy osteocemenlum PALAC05accordingto prescription.Presently,we are looking Cranioplasty may be necessary after trauma, cranial tumor resection, or in- for a method enabling us to extend our copy system onto bone removed for infection, fection_ The aim may be either to protect the underlying brain, orrestore to cosmeticallythe reSUltingdeformities. Several materials are in use toperform cranioplasty : autogenousbone, methyl-methacrylate,titanium. All of them have their advantages and disadvantages. The most popular materialmethyl-methacrylatefor instance, is a
I
I
I
I
IP-3-362I
Microsurgicalanatomy of theposteriorregion of the limbicsystem seen by the supratentorial-infraoccipital approach
S. Gusmao, R.L. Silveira,G. Cabral, A. Andrade. HospitalMadre Teresa, Belo Horizonte,Brazil Introduction:Accordingto Yasargil (1984), "thesubarachnoidalcistems are theroadmapsfor themicroneurosurgeon". The supratentorial-infraoccipital approach providesan avenueto theposteriorregion of the limbicsystem. It is carriedoutthrougha naturalspacebetweentheinferomedialpartof theocciptal lobeand thetentorium.The purposeof this work is to studythe posteriorregion of the limbicsystemthat can be visualizedby thisapproach. Material and Methods: Amicrosurgicalanatomystudy wasundertakenin approachwasperformed 10 cadavericheads. The supratentoral-infraoccipital as thetechniqueproposedby Clark WK(1987). Results: Theparahippocampalgyrusextendsfromtheuncusto theisthmus of thecingulategyrus andcontinuesto themedial occipitotemporalgyrus. Its posteriorpart extendsupwardand medially,and isdirectedto thespleniumof the corpuscallosum,as afolding,theisthmusof thecingulategyrus,whichjoins theparahippocampalandcingulategyri.Theisthmusextendsobliquelyupward and posteriorand itsconcave partpasses around thespleniumof the corpus callosum.In theretrothalamiccistern,the posteriorpart of thepulvinarof the thalamusis located anterolateralto the triangle formed by the quadrigeminal plate and thespleniumof the corpuscallosum,which are in themidline,and theisthmusof thecingulategyrus,posterolateralto theselasttwostructures.In the ambient andquadrigeminalcisternswe canidentifythe posteriorcerebral arteryand itsbranches,and the basilarvein of Rosenthalandinternaloccipital veins. Conclusions:The posteriorregionof the limbic systemcan beexposedby thesupratentorial-infraoccipital approachwithouttransectingthecortexandthe ventricles.
IP-3-363!
Temporobasal approach to lesionsin and/or near the temporal horn andtrigone
M. Nishikawa,M. Matsumoto,T. Mizutami, R. Ishizaki,H. Yoneda, A. Kaneko. Departmentof Neurosurgery,KokuraMemorialHospital,Kitakyushu,Japan temporalhornandtrigone,especially Introduction:Lesionsin and/ornearthe of thedominanthemisphere, are difficult toremove, because of theirdepth, injury toWemicke's area and the opticradiation. We use the lateral basal approachto lesionsof this area and havehad goodresults.We are reporting thismethodand ourexperiences. Clinical Material and Methods: Five AVMs, 2 cavemomas, and 1 brain tumor wereoperated on in ourdepartmentsince 1993 with thismethod. The operativemethodis asfollows;a temporalosteoplasticcraniotomyis madewith a lateralpositionloweringvertex down. It isimportantto remove thetemporal bonedeepto the middlefossa.After openingthe dura,the baseof the temporal lobeisexposedbyretractingslightlythe lateralpartof it andthe occipitotemporal sulcus, which is located about 2 cm inside of the lateral part of thetemporal lobe, isopened. Enteringthe sulcus,medialto the opticradiation,theventricleis easilyreached. Once thesurgeonis in thetemporalhorn,anatomicorientation becomeseasier. In casesofAVM, the anteriorchoroidalartery, whichinvariably feeds the AVM,canbe followedto the lesion.Tumorsandcavernomascan be seenthroughthe ependyma. Results: Onepatientwith recurrentAVMsufferedfromaquadranthemianopsia and another patient with AVM mild paresthesia.All otherpatientsshowed noneurologicaldeficits. Conclusion:The lateralbasalapproachis averyusefulmethodforexcision of lesionsin area.
Technology - SurgicalApproaches
IP-3-364!
S153
The combinedsubtemporal-suboccipital approach. A modifiedsurgical access to the clivusand the petrousapex
AbolghassemSepehrnia, UlrichKnopp. NeurosurgicalDept., Universityof LObeck, Germany Introduction:The surgicalaccess to the clivus and the petrousapex is still a challenge.A combinedapproachis best fitted to tumors locatedin the middle and posteriorcranialfossa. The approachdescribedin our series iscentered on the petrous bone andrequires an extensive petrous-boneresection. An osteoplasticbone-flapis no longernecessary. Methods: We report on the last fiveconsecutivepatients, whounderwent surgeryusingthefollowingtechnique:The petrousbone is drilledawayanterior unroofed.Forexposureof the middlecranial to thesigmoidsinus, the sinus is fossa thepetrous boneshould be resected down to the roof of the external meatus. Results: Thesurgicalaccessasdescribedaboveprovidesa wideoperative fieldwithpreservationofimportantintracranialstructuresas showninour series. Discussion and Conclusion: This modifiedapproachminimizesthe cerestructurescan be bellarandtemporalloberetraction.The neural and vascular preservedunder directvision to thetumor. The blood supply is interruptedin thebeginningof theoperation.
IP-3-36SI
A modified surgicaltechniquefor thepresigmoid approach:Osteoplastic mastoidectomy followedby single-flaptemporo-suboccipital craniotomy
Yutaka Sawamura, TsutomuKato, HiroshiAbe.Departmentof Neurosurgery, HokkaidoUniversitySchoolofMedicine, Sapporo,Japan Objective: Thecombinedsupra-andinfra-temporaltranspetrosalapproach,the presigmoidapproach,requiresa temporalsuboccipitalcraniotomyand unroofing of the duralsinuseswithmastoidectomy.Toreduce the bone defect in the mastoidareaandtodecreasethe riskofinjuringthe duralsinuses,we describe a modifiedsurgicaltechnique,and inaddition,demonstratethe usefulnessof fibringlue inmastoidbonereconstruction. Methods:Beforethecraniotomy,a surfacemastoidectomywas carried out using a rongeur to preserve bonefragments for laterreconstructionof the mastoid process. Through the cavityresultingfrom themastoidectomy,the dural sinuses were dissectedfrom their bony grooves.A single-flaptemporosuboccipitalcraniotomywas thenperformed.Uponclosure,after fixation of a temporo-occipitalbone flap, amixtureof the bone chips and human allogenic fibrin glue withantibioticwas molded and placed to fill bony defects in the mastoidprocess. Results: Ninepatientswereevaluatedafterfor morethana year. Therewere nocomplicationsdirectlyrelatedto theosteoplasticmastoidectomy.Neitherosteomyelitisnormastoiditisoccurred.Follow-upthree-dimensionalCT revealed that seven of ninereconstructionsof themastoidprocessremained sufficient; but in two cases the bone chips were absorbedwithin eight months after the surgery. Conclusion:Osteoplasticmastoidectomyfollowed by en-bloc temporooccipitalcraniotomyenables minimizationof the bone defect in themastoid area. In addition,beginningwith amastoidectomyfacilitatessafedissectionof the outerduracoveringthesinusesandadherentto the bonygroove.
I P-3-366I
Preliminaryexperience with 4 kinds of combined transpetrosalapproach forintracranialt umours
ShenJiankang,Uu Chengji,Hu Bingchenet al. Departmentof Neurosurgery, RuijinHospital,ShanghaiSecondMedicalUniversity,Shanghai, PR China Seventy-twocases ofintracranialtumor, most of which werecerebellopontine angletumors, were operated on by 4 kinds ofcombined transpetrosalapproach. Of them, 34 cases were acoustic neuroma and wereoperated on by a translabyrinthinetranstentorialapproach. Seventeen cases werecerebellopontineangletumorincludingmeningioma,cholesteatoma,glioma,chordoma, neuroma except foracousticneuroma, which wereremoved via a transmastoid-transtentorial approach.Threecasesweretrigeminalneuromaofhourglass type,6 caseswerechordomaorcholesteatomaand 2 casesweremeningioma oftentorialedge, whichwereremovedby a combinedtransmastoid-transtentorialandsubtemporalapproach.Seven casesofmeningiomaincerebellopontine angleor clivusand 3 cases of chordomain clivus were treatedby caombined transmastoid-transtentorial and retrosigmoidapproach.Totalremoval of tumor was achieved in 65 cases(90.6%). Sixty-fourcases had goodpostoperative outcome,7 caseshad poor resultand one case died. Main postoperativecomplicationin relationto theapproach is CSF leakage in 3 patients, which was cured byreoperativerepair in one and by lumbar CSF drainage in other two. Advantagesof thecombinedtranspetrosalapproachincludea wideroperative indication,wideningtheoperativefield,shorteningoperativetime anddecreas-
5154
Tuesday, 8 July 1997
Technology- Miscellaneous
ing postoperativecomplications , 50 the extended trarfspetrosalapproach is very usefulfor removalof cranial base tumor in middle orlandposteriorfossa.
rather cheapmaterial, easily suitable to cover a defect, but causes frequent inflammatoryreactionaroundtheimplant. In the last 2 yearswe tried to usea newalloplastic material"Os proge l ~ that iscomposedof Hydrohyapatite , boneprotein derived gel, and water, and that is P-3-367! Reconstructionof skull defects with homograftskull not only areplacingmaterialbut also abiologicalactivesubstance,by inducing bone new boneformation,This has beendemonstratedin many cases treated by dentalandmaxillo-facialsurgeons. ZhiyongVan, Shugan Zhu,HongweiHe. DepartmentofNeurosurgery,the With thismaterial we performed7 cranialreconstructionsusing either OsAffiliatedHospitalof ShandongMedical University,Jinan, PR China titanium mesh andlorplate progel alone for smaller defects, Osprogelwith or Six rabbitsunderwentreconstructionof skull defect with homograftskull bone. curvatureand to assure a proper in largersizes, in order to maintain the right 01 skull defect. The There were six control animals that did not have repair guide for boneregrowth. The best results were obtained in medium sized deresultsofcompressiontest and thepathologicalmorphologyindicate: (1) Skull fects (about15--20 sq.cm) usingOsprogelwith a support of titanium net fixed bonehomografts with the contour of therroundin su g skull boneafter 8months; with microscrews to the border of the craniectomy . Good results were also (2) The homograftshave no significant differencescomparedwithnormalskull; obtained in those cases where taitanium mesh was included in a sheet of (3) The formationof new bone does not affect the function of the dura mater Osproge1 (·Osprotitantex "~) . When correctly used, that meansthat Osprogelis or the brain. There were 7 patients with skull bone homogralts.The follow-up kept in contact with healthy cancellousbone. After six monthsthe defectswere periodsof the patientswere from 6 to 18 months. The reconstructedsites have completelyfilledbynewlyformed bone, as seen on 3D reconstructedCT scans. compressedand are a normalappearancewithoutdepression, are solid when analogousto the normalskullbone. No focalfluid collectionorinfectionoccurred afteroperation. Nocomplicationsoraggrevationof the priorsymptomsoccurred I P-3-370 I The use ofhydroxyapatiteceramics in the afterreconstruction . reconstructionof surgicalskulldefectsfollowinga
I
frontotemporalapproach YojiNode, AkiraTeramoto. Departmentof Neurosu rgery, Nippon Medical SchoolTokyo, Japan Purpose: Large portions of the supraorbitalmargin, the cheek bone, and the sphenoidbone arecommonlyremoved as part offrontotemporalsurgery for deepcerebral aneurysmsand basaltumors. In most cases, it is not possible to Tuesday, 8 JUly 1997 14:00-16:15 retain the original form of the bone flap, and fragments of bone are employed to restorethe shape when closing the skull. The resin used brings with it the risk P-3 Technology - Miscellaneous autogenousbone is insufficient for restoration. The of infection, and the use of authorsreporttheir experimentswith hydroxyappaiteceramics(HAC)as an aid problems,and its use inreplacingmissing bone in the locations to solving these mentionedabove. P-3-368I New hardware andsoftwaretoolsto makefunctional Method: Nine patients (four males, five females, mean age - 54 years) imaging a reliablepreoperativeprocedure were treated, 6 forcerebral aneurysms,and three for basaltumors. HAC was employedto replace missingbone in the supraorbitalmargin,the cheek bone, T. Hoell,F. Oltmanns, A. Schilling, M. Brock. Dept. ofNeurosurgery.Benjamin and the sphenoid, torestoreskull shape. The HAC consistsof an inner portion FranklinUniversity Hospital, Berlin, Germany forming the inside of the skull, and an outer portion (the skull surface). The Introduction:The most important application of functional imaging,particularly externalportion is formedintothin, triangularpieces, and usedas the base onto is the preoperativeidentificationof eloquentareasof the cortex. This technique whichthe inner portion, also in the form of thin triangularpieces, is attached. hasbecomean adequate researchtoolbutstill lacksthe highdegreeof reliability Conclusions:(1) The amount of missing bone differed between patients. necessaryto identityfunctionalareasrequiredforsurgicalplanning. Problems However, astrimmingis accomplishedcomparatively easily, the amount reare the transmission of cognitive optical stimuli to the patient, the finding of quired for each defect may be adjusted for each patient and no particular an adequate sensory stimulus that can be used for fMRI and perioperative problems were experienced. (2) No post-operative infections were noted. (3) investigation of sensoryevokedpotentialsin the same manner. consideredsatisfactory . Cosmeticbenefits are designedfor the transMethods and Techniques: A fiberoptic systemwas mission of optical stimuli. An appropriatehead set wasintroducedto reduce MR noise and to apply acoustic stimuli. A patent was filed for a pneumatic P-3-371 An alternativetechnologyfor Identicalreplicationin systemfor touchingthe skin with precisionof a less than 4 ms, whichis precise the multiple fractured skull enough to apply identical stimuli for pre- and perioperative 5EP testing. SoftE. Schultke,J, Hampl, J. Koy, L. Jatzwauk ' , G. 5chackert.Dept. of opticalstimuli and a set ware wasdevelopedto activate the motor cortex via Neurosurgery.TU Dresden,Dresden, Germany, , Dept. of Microb iology, TU of newparadigmswas tested for activation of different componentsof speech Dresden, Dresden, Germany functions. Results: The optical activation system was used153 in patients.Reliable Traditionallythe reconstructionof major bone defects in the skull with multiple functional images could be obtained in 85% of all cases. In 12 cases the fracturesis performedusingosteocementumafterregressionof initial cerebral functionalimages were used to decide upon the best neurosurgicalapproach. oedema has occurred. As has been shown before (Koy, unpublisheddata) in Postoperativecognitive investigation revealed a successfulplanningstrategy. only10 out of30 patientswhounderwentthisprocedurethe cosmeticresultand All softwarecomponentshave been usedsuccessfullyunderclinical conditions thefitof theimplantrangedbetweengoodandvery good.whilstin the remaining componentsare still under investigation in casesthe mostcommonfaults were gaps and steps betweenplastic and skull. for more than one year. The other To avoid these problems we have developed an easy method based on a ongoingresearch. Conclusion: The introductionof new hard- andsoftware toolsimproved plaster-castproceedingusingsterilizedgypsum, The method allows identical functionalimagingto a level,whichallowsa consolidatedpreoperativedecision reconstructionof the original part of the skull and implies the need for an makingbased on thefunctionalimagesofindividualpatients. acceptable cosmeticoutcome. As the implant can be shaped under sterile conditionsat any time beforethe beginningof actualsurgeryanother advantage is the savingof time. P-3-369! Cranioplastieswith thealloplasticmaterial The first requirement for the production of identical copies in skull defects "Osprogel" ®; Differentmodalitiesof applicationand is the availability of all parts of the original calvaria, only an extremely minor results fragmentmay be omitted. The secondrequirementis the availabilityof sterilized gypsum (dubble hot-air sterilization) so as to avoid any interruptionsin the AlfredoPompili, Carmine M. Carapella FabrizioCaroli, , FabioCattani, sterilizationprocedure. After assembling thefragmentsin the original shape MaurizioFontana, GiancarloSestili 'EmanueleOcchipinti , . Div. of of the skull a gypsum matrix ind uding both a convex and a concave cast Neurosurgery.Rome, Italy, , Diagnostic Radiology Ist/turoReginaElena, Rome, is moulded. Afterhardening the implant is modeled in this matrix using the Italy osteocemenlum PALAC05accordingto prescription.Presently,we are looking Cranioplasty may be necessary after trauma, cranial tumor resection, or in- for a method enabling us to extend our copy system onto bone removed for infection, fection_ The aim may be either to protect the underlying brain, orrestore to cosmeticallythe reSUltingdeformities. Several materials are in use toperform cranioplasty : autogenousbone, methyl-methacrylate,titanium. All of them have their advantages and disadvantages. The most popular materialmethyl-methacrylatefor instance, is a
I
I
I
I