P OSTER PRESENTATION ABSTRACTS111. Decompressive Hemi-Craniectomy in

Patients With SubarachnoidHemorrhageWolfgang Deinsberger, MD; Heiko Mewes,MD; D Hoffmann; Matthias Oertel, MD;Dieter K. Boeker, MD (Giessen, Germany)

Introduction: In patients with aneurys-mal subarachnoid hemorrhage (SAH)ischemic brain edema may result inraised intracranial pressure and herniation. Decompressive surgicaltechniques are currently used inischemic stroke with highly variableresults. The aim of this study was todetermine whether decompressivehemi-craniectomy improves outcomeafter SAH. Methods: In 16 SAH patients (meanage 48 plus or minus 10 years) decom-pressive craniectomy was performed.The patients' charts were retrospectivelyreviewed. Hunt & Hess (HH) score,Fisher Grade, preoperative and postoperative CT scans were collected.Intracranial (ICP) and cerebral perfu-sion pressures (CPP) were recorded 2hours pre- and post surgery. Glasgowoutcome score (GOS) was assessed at 12 months after SAH.Results: On admission HH scores 2, 3 and 4 were seen in 2, 2 and 10patients, respectively. All patientsexcept one were treated within 48hours after ictus In 5 patients craniec-tomy was performed as part of the surgical approach to the rupturedaneurysm in order to evacuate a largeintracerebral hematoma. In 11 patientscraniectomy was performed 7 plus orminus 4 days after the ictus. In eightpatients anisocoria prompted surgery.ICP was significantly reduced aftercraniectomy (14.3 plus or minus10.3mmHg vs. 9.4 plus or minus 9.5, p equal 0.026). CPP increased not significantly. Unfavorable outcome(GOS 1-3) was seen in 81% of patients.None of the patients experienced fullrecovery. Two of the three patients with GOS 4 had craniectomy during theinitial surgery.Conclusions: Although decompressivecraniectomy is able to reduce elevatedICP, outcome is not improved. Basedon this limited data decompressivehemi-craniectomy cannot be recom-mended as a treatment for brain edemaafter SAH.

112. Multimodality Treatment ofLarge/Giant Internal CarotidAneurysms: Angiographic Results andLong-term Outcome in 102Consecutive CasesSeung-kon Huh, MD, PhD; Jae Whan Lee,MD; Kyu Chang Lee, MD, PhD; Dong IkKim, MD, PhD (Seoul, Republic of Korea)

Introduction: Large/Giant (greater than15 mm in diameter) internal carotidaneurysms (LGICA) are challenging to secure the sac surgically orendovascularly. Angiographic results,complications, and long-term clinicaloutcome were analyzed to clarify theselection of optimal managementmodality for LGICA. Methods: Among 908 internal carotidaneurysms, LGICA were 102 cases(11% of 908 IC aneurysms; 69intradural, 33 extradural; 50 ruptured,52 unruptured; 68 large, 34 giant).Treatment modalities were clipping for41 patients, coiling for 20, and carotidocclusion for 41 (35 balloon occlusion,3 surgical trapping, 3 carotid ligation).Therapeutic results of lesion repair,long-term clinical outcome, and causesof unfavorable outcome were analyzed.Results: The overall outcome wasgood in 82 patients (80%), fair in 11(11%), poor in 4 (4%), and death followed in 5 (5%). Initial insult (4patients), lobar or focal infarct (2 afterclipping, 1 after ballooning), andrebleeding (2 after ballooning, 1 afterclipping) were the major causes ofunfavorable outcome. Angiographicresult of coiling was 60% completepacking, 20% neck remnant, and 20%incomplete packing. Major complica-tions of coiling were cranial nerve palsydue to mass effect, embolic infarct, andintramural hemorrhage.Conclusions: Surgical clipping wouldbe recommended for lesions ofintradural ICA; perforator injuries andcarotid occlusion should be avoided.Carotid balloon occlusion would bepreferred for extradural ICA lesions;close follow-up would be necessaryfor prevention of aneurysmal ruptureespecially in intradural lesions. Coilingcould be reserved for the paraclinoidlesions; follow-up angiogram would benecessary for detection of recanaliza-tion and coil compaction.

113. Posterior Circulation FusiformAneurysms: Results of Surgical,Endovascular and CombinedTreatmentBert A. Coert, MD; Robert L. Dodd, MD,PhD; Mary L. Marcellus, RN; Huy M. Do,MD; Michael P. Marks, MD; Steven D.Chang, MD; Gary K. Steinberg, MD, PhD(Stanford, CA)

Introduction: Fusiform aneurysms are a rare anatomical and clinical entity . The circumferential vessel wallinvolvement and perforating branchescomplicate surgical and endovascularmanagement. Studies on the naturalhistory of fusiform aneurysms haverevealed yearly rupture rates of 1-2 %and an ischemic event rates of 5 %/year.Materials and Methods: Between 1991and 2004 forty-three patients weretreated at Stanford UMC for fusiformposterior circulation aneurysms. Male :female ratio was 24:19.Average agewas 54 y. Twenty-five patients present-ed with a subarachnoid hemorrhage.Nineteen percent (eight) patients wereHunt & Hess grade IV on admission.Thirty-seven percent (15) of theaneurysms were located on the verte-bral artery, twenty-five % (10) on thePCA, 18% (7) on the VBJunc, 15% (6)on the BA and 5% (2) on PICA. Twentyfour patients underwent endovasculartreatment while 17 underwent surgeryand two combined treatment. Glagowoutcome scores (GOS) were recorded .Follow-up ranged from 3 months tothree years. Results: Average pre-treatment H Hscores were significantly higher forwomen than for men. Female patients13/19 (68%) presented more fre-quently with a SAH in comparison tomen 12/24 (50%). The overall mortalityrate was 9 % (4/43). GOS IV - V wasachieved in 53% (23/43). There wereno significant differences in outcomewith gender or between the differenttreatment modalities, pre-treatmentconditions or aneurysm locations .Patients under 45yo had significantlybetter outcome. Conclusion: Endovascular and surgicaltreatment of fusiform posterior circula-tion aneurysms can lead to good out-come even in poor-grade patients.

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114. Aggressive Mechanical Clot DisruptionFollowing Intravenous Thrombolysis forIschemic Stroke: A Feasibility and SafetyStudyAdnan I. Qureshi, MD; Jawad F. Kirmani, MD;Pansy Harris-Lane, NP; Afshin A. Divani, PhD;Molly Jacob, NP; Shafiuddin A. Ahmed, MD;Ammar AlKawi, MD (Newark, NJ)

Introduction: We prospectively evaluatedthe safety and effectiveness of aggressivemechanical clot disruption following intravenous thrombolysis to treat ischemicstroke in patients considered poor candi-dates for intravenous alteplase therapyalone to increase the recanalization ratewithout increasing risk of intracerebralhemorrhage. Methods: Poor candidates for intravenoustherapy (Initial National Institutes of HealthStroke Scale (NIHSS) of greater than orequal to 10) underwent emergent cerebralangiography following administration ofintravenous alteplase (0.9 mg/kg). Ifintracranial occlusion was demonstrated,mechanical angioplasty or snare manipula-tion at the occlusion site was performed.Clinical evaluations were performed beforeand 24-hours, 7-to- 10-days, and 1-to-3-months after treatment.Results: Eighteen consecutive patientswere treated (mean age, 64.8 plus orminus 13.7 yr; 9 were men). Initial NIHSSscores ranged from 12 to 21. An occlusionwas demonstrated in 15 of 18 patients.Thrombolysis alone was used in 4patients, microcatheter exploration in 4patients, angioplasty in 3 patients, andsnare maneuvers in 7 patients. Time tointravenous thrombolysis and time tomicrocatheter placement were 116 plus orminus 32 and 222 plus or minus 35 min-utes. Complete restoration of blood flowwas observed in 6 patients. Decline of atleast 4 points in NIHSS score wasobserved in 11 of 18 patients at 24 hours.No vessel rupture, dissection, or sympto-matic intracranial hemorrhages wereobserved.Conclusions: The present study demon-strates the feasibility and safety ofmechanical disruption of clot followingintravenous thrombolysis. Although furtherrecanalization was observed in more thanone-third of the patients, new strategiesare required to further improve therecanalization rates

115. Risk of Rupture Post-EndovascularTherapy for Vasospasm in SubarachnoidHemorrhage Patients With IncidentalUnruptured-Unsecured AneurysmsVallabh Janardhan, MD (New York, NY); MadhuB. Vijayappa, MD; Joshua A. Hirsch, MD; JamesD. Rabinov, MD; Johnny C. Pryor, MD; NeerajBadjatia, MD; Bob S. Carter, MD; Christopher S.Ogilvy, MD; Guy Rordorf, MD (Boston, MA)

Introduction: Although, hypertensive and hypervolemic therapy for cerebralvasospasm due to subarachnoid hemor-rhage(SAH) has been reported to be safein patients with incidental unrupturedunsecured aneurysms(IUA), the risk ofrupture of IUA following endovasculartherapies, including intra-arterial infusionof vaso- dilators and angioplasty of vesselsproximal to IUA, remains to be defined. Methods: Charts of all patients with dis-charge diagnosis of SAH(ICD 9 code430.0) between 1/1998 and 2/2004 werereviewed to identify patients with cerebralvasospasm who underwent endovasculartherapies and had IUA at time of therapy.Patients with IUA who underwent angio-plasty of vessels contra-lateral to IUA wereexcluded(n=3). Patients with residualaneurysms/unsecured ruptured aneurysmswithout IUA were excluded(n=3). None ofthese patients excluded from this analysis(n=6) had any re-bleed during or after(within 24 hours) endovascular therapy.Results: 21 patients(Mean age:57.9years,range:34-86years; Women:81%,17/21) with SAH having 41 IUA(Mean=1.95 aneurysms/patient; range=1-5aneurysms/patient) developed vasospasmrefractory to medical therapy and requiredendovascular therapy. The rupturedaneurysms were secured in 19 patients attime of vasospasm therapy (clip=11;coil=8; angio negative=1) and one basilaraneurysm was coiled after vasospasmtherapy. Endovascular therapies included intra-arterial papaverine (n=10;4/10 patients also had angioplasty), intra-arterial nicardipine (n=10;2/10 patientsalso had angioplasty), and angioplasty(n=1). Angioplasty proximal to IUA wasperformed in 2 patients. Mean number ofendovascular treatments per patient= 2(range =1-4 treatments/ patient). None ofthe IUA ruptured and none of the r u p t u r e d -unsecured aneurysms re-bleed during orafter (within 24 hours) endovascular therapy.Conclusion: Endovascular therapies forcerebral vasospasm seem to be safe inSAH patients with IUA and are not associ-ated with an increased risk of rupture.

116. The Utility of Intraoperative Blood FlowMeasurement in Aneurysm Surgery Usingan Ultrasonic Flow ProbeSepideh Amin-Hanjani, MD; Guido Meglio, MD;Rodolfo Gatto, MD; Fady T. Charbel, MD(Chicago, IL)

Introduction: Inadvertent vessel compro-mise is one major cause of unfavorableoutcome from aneurysm surgery. Existingstrategies for intra-operative assessmentof this complication have potential limita-tions and disadvantages. We assessed theutility of quantitative intraoperative flowmeasurements using the TransonicsSystems ultrasonic flow probe duringaneurysm surgery.Methods: Of all aneurysms treated surgically at our institution from 1998-2003, 103 patients with 106 aneurysmswere identified in whom intraoperative flow measurements were available foranalysis. We assessed the frequency offlow compromise and clip repositioningand correlated these with postoperativeangiography and stroke.Results: Significant (more than 25%) flow reduction was apparent in 33 (31.1%)cases, and resulted in clip repositioning in27 (25.5%), with return to baseline flowexcept for two cases with vessel thrombo-sis/dissection. In the other 6 cases flowreduction was due to spasm resolving withpapaverine (n=3), or responded to retrac-tor repositioning (n=3). In another 6(5.7%) cases, unnecessary clip reposition-ing was avoided (n=3) or safe occlusion of the parent vessel for trapping of theaneurysm was allowed (n=3). Aneurysmsof the basilar, middle cerebral, anteriorcommunicating or carotid terminus weremore likely to be associated with flowcompromise (OR 4.3, P=0.03).Postoperative angiography corroboratedvessel patency in all cases; no unexpectedlarge vessel occlusions or strokes wereevident.Conclusions: The ultrasonic flow probeprovides real time immediate feedbackconcerning vessel patency. Vessel compro-mise is easier to interpret than withDoppler, and faster/less invasive thanintraoperative angiography. Intraoperativeflow measurement is a valuable modality forenhancing the safety of aneurysm surgery.

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P OSTER PRESENTATION ABSTRACTS117. Doppler Ultrasonography Used

for Carotid Stenosis Detection:H i s t o p a t h o l o g i c a l Study ofMeasurement AccuracyDavid Netuka, MD; Vladimir Benes, MD,PhD; Vaclav Mandys, MD, PhD; JanaZvarova, MD, PhD; Jana Hlasenska, BA;Milan Mohapl, MD; Filip Kramar, MD(Prague, Czech Republic)

Introduction: Prospective study comparing carotid stenosis accordingto doppler ultrasonography with meas-urement on histological specimen. Methods: In 123 cases doppler ultra-sonography and intact carotid plaquesremoved in one piece during surgerywere obtained. The specimens were histologically processed andtransversally cut. The smallest innerand correlating outer diameter weremeasured and degree of stenosis wascalculated. Stenoses were compared,statistics done, here not presented dueto small extent of abstract. Specimensin symptomatic cases (79) were divid-ed into 3 groups according to ultra-sonography: Group I - stenosis 30-49%, n=2; Group II - stenosis 50-69%,n = 22; Group III - 70-99%, n = 52.Specimens in asymptomatic cases (47)were divided into Group I- less than60%, n = 7 and Group II - more than60%, n = 40.Results: In symptomatic Group I bothcases were stenoses bigger than 50%according to measurement on histolog-ical specimen, in Group II 6 cases(27,27%) were stenoses bigger than70% according to specimen measure-ment. In Group III 20 cases (38,46%)were stenoses 50-69% according tospecimen measurement. In asympto-matic cases results are as follows:Group I- 4 cases (57,14%) werestenoses bigger than 60% according tospecimen measurement. In Group II- 5cases (12,5%) were stenoses lesserthan 60% according to specimenmeasurementConclusions: There is a high propor-tion of under diagnosed cases mainlyin symptomatic Group I, II and asymp-tomatic Group I stenoses. In contrarythere is a proportion of cases in GroupIII which is overestimated. Supportedby : IGA 6980-3, 6985-4, LN 00B107

118. Outcomes in Endovascular Treatmentof Medically Refractory VasospasmMarshall Tolbert, MD; Osama O. Zaidat, MD;Michael J. Alexander, MD, FACS (Durham, NC)

Introduction: The development of arte-rial vasospasm remains a major deter-minant of outcome in patients experi-encing aneursymal subarachnoid hem-orrhage. We retrospectively reviewedpatients undergoing endovasculartreatment of medically refractory, clini-cally severe vasospasm, in regard tobrain CT changes, clinical improvementand outcome at discharge. Methods: Data was collected from a retrospective chart review of 143consecutive patients admitted between1999 and 2003 with aneurysmal SAHwho underwent either clipping or coiling. Thirty-one patients underwentendovascular treatment for sympto-matic, medically refractory vasospasm,and form the study group. A total of 41 procedures were performed, 16papavarine infusions, 19 balloon angio-plasties, and 6 combined procedures.Results: Changes consistent withacute ischemia or infarction on CTwhere observed in 19 of the 31patients, which correlated with thepatients neurologic deficit. Despite CTevidence of ischemia or infarction, 11patients (58%) were discharged toeither home or a rehabilitation facility;5 (26%) were discharged to a skillednursing facility, and 3 (16%) expired.Clinical improvement followingendovascular treatment occurred in 20patients (64.5%), 15 of which weredischarged to either home or to a rehabilitation facility, and 5 dischargedto a skilled nursing facility. Overall, 20 patients (64.5%) were ultimatelydischarged to either home or to a reha-bilitation facility, 8 (26%) were dis-charged to a skilled nursing facility, and3 (9.5%) expired during hospitalization.Conclusions: Endovascular treatmentis an effective adjuvant treatment forpatients experiencing medically refrac-tory vasospasm from aneurysmal SAH.Clinical improvement can be obtainedeven in the presence of cerebralischemia or infarction on CT scan.

119. Long-Term Clinical and AngiographicOutcome Following Carotid ArteryAngioplasty and Stenting forRadiation Induced StenosisOsama O. Zaidat, MD; Ashutosh Pradhan,MD; Marshall Tolbert, MD; Paul Peterson,MD; Tony P. Smith, MD; Michael J.Alexander, MD, FACS (Durham, NC)

Introduction: Radiation-inducedcarotid artery stenosis is well-knownindication for carotid artery angioplastyand stenting (CAS). We present thelong-term clinical and angiographicoutcome following CAS in 33 patientswith radiation-induced carotid arterystenosis. Methods: CAS was performed according to published standard with appropriate anticoagulation.Demographic and imaging data weredocumented in all cases with historyof neck radiation. The re-stenosis wasdefined as more than 50% diameterstenosis within or at the ends of thestent by carotid ultrasound. The re-stenosis was confirmed by conven-tional angiography or computerizedtomographic angiography (CTA). The clinical outcome was defined asipsilateral transient ischemic attack orstroke. Long-term mortality was alsodocumentedResults: A total of 33 CAS were performed in 29 patients with radia-tion-induced stenosis. Seventeen(52%) were symptomatic, with 75%average degree of stenosis. Six caseswere in the common, 8 cases in thecommon and internal, and 19 cases at the bifurcation or internal carotidartery. Clinical follow-up was availablein 25 procedures, with mean period of14.1 months. Two events occurred(8%), 1 minor stroke and 1 TIA. A thirdpatient had a seizure disorder, and onefatality occurred three days followingCAS, with intracranial hemorrhage(4%). Twenty-two patients had imagingfollow-up with mean of 13.5 months,and 5 (22.7%) had re-stenosis. Twowere re-treated and had no resultantstenosis, two had complete occlusionand one deferred further treatment.Conclusions: CAS in patients with radiation-induced stenosis is associat-ed with comparable rate of long-termclinical outcome and vessel patency as primary CAS for atherosclerotic disease.

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120. Early Experience With Matrix Coils in theTreatment of Intracranial AneurysmsDennis J. Rivet II, MD; Avi Mazumdar, MD;Colin P. Derdeyn, MD; DeWitte T. Cross III, MD;Christopher J. Moran, MD (St. Louis, MO)

Introduction: This study was undertakento evaluate the performance of the recentlyintroduced Matrix coils in the treatment ofintracranial aneurysms at a single centerand compare it to a cohort of patientstreated with bare platinum coils. Methods: Seventy-three patients under-went treatment of a total of 84 aneurysmswith Matrix coils in the 15 month studyperiod. The Matrix-treated group consistedof 18 males and 55 females, and 24 of thegroup had suffered subarachnoid hemor-rhages. Angiographic follow-up was avail-able in all patients. Fifty-eight aneurysmswere in the carotid circulation and 18 inthe vertebral-basilar distribution.Adjunctive treatment measures, such asballoon remodeling and Neuroform stentplacement were utilized in some cases,and recorded. The aneurysm recurrencerate and complications were reported.Results: The aneurysm recurrence ratewas 27%, and included many wide-neckedand giant aneurysms among those treated.Thrombus formation as a complicationoccurred in 3.5% of aneurysm treatments.Conclusions: Though experience with theMatrix coils is in its early stages, the treat-ment of intracranial aneurysms with thesedevices is promising. The complicationsrates are similar in Matrix and bare plat-inum coils, while the recurrence rate iswithin the historical ranges for bare plat-inum coils. This is despite the fact thatmany wide-necked and giant aneurysms were treated.

121. Risk Factors of Ischemic ComplicationsInduced by Postprocedural HypotensionFollowing Carotid Artery StentingTadashi Nonaka, MD, PhD (Sapporo, Japan)

Introduction: Stenting procedures, especially for bilateral carotid lesions,might produce drastic hemodynamicchanges with ischemic complications. Thisstudy is performed to investigate the fre-quency of and risk factors for hypotensionin response to elective carotid stenting. Methods: Forty-three lesions of 39 consecutive cases (mean age 70.3 plus orminus 8.2 years) were retrospectively ana-lyzed. In these cases there were 10 caseswith bilateral lesions, including two caseswith occlusion of contralateral ICA. EasyWall stent was applied in 14 lesions andSMART stent in 29 lesions. We investigat-

ed correlations between the occurrencerate of postoperative hypotension under 90 mmHg and persisting over 3 hours and findings of preoperative angiogramsand ultrasonograms and clinical characteristics.Results: Postprocedural hypotensionoccurred in 18 lesions (41.9%) and med-ical treatment (intravenous administrationof catecholamines) was required in 10lesions (23.3%). Although there was nopermanent neurological deficits relatedwith the postprocedural hypotension, tran-sient neurological deficits were found in 3cases and transient worsening of ASO inone case. Risk factors of postproceduralprolonged hypotension were statisticallyanalyzed. On clinical characteristics; sortof stent (SMART vs. Easy Wall p=0.0375)On angiographic characteristics;1) dis-tance between carotid bifurcation andmaximum stenosis (less than10mm vs.greater than10mm: p=0.0011), 2) type of stenosis(concentric vs. eccentricp=0.0403) On ultrasonographic character-istics;1) calcifications at the carotid b i f u rcation (present vs. abscent :p=0.0001).Other variables, including age and degreeof stenosis, were not associated with postprocedural hypotension after carotidstenting.Conclusions: These angiographic andultrasonographic variables can be used toidentify patients at risk for postproceduralhypotension after carotid stenting. Suchidentification may help in selection ofpatients who may benefit from appropriatepharmacological treatment.

122. Interobserver Agreement in Assessingthe Severity of Arterial Occlusion forAcute Ischemic Stroke Cases Using theQureshi Grading SchemeAmmar AlKawi, MD; Jawad F. Kirmani, MD;Pansy Harris-Lane, RN; Shafiuddin Ahmed, MD;Afshin Divani, PhD (Newark, NJ)

Introduction: The Thrombolysis inMyocardial Infarction (TIMI) gradingscheme is limited in that it does notaccount for occlusion location or collateralcirculation. Qureshi proposed a newscheme for angiographic classification of arterial occlusion and recanalizationresponse to intra-arterial thrombolysis in acute ischemic stroke. Methods: Consecutive angiographic stud-ies in acute ischemic stroke patients wereindependently reviewed by a neurointer-ventionalist and a stroke neurologist. Theseverity of occlusion was graded a score from 0 to 5 on the basis of occlusion siteand collateral supply. Grades 3 and 4

occlusions were sub classified accordingto predefined criteria. The angiogramswere also classified according to TIMI perfusion grade scheme (0-3). The interobserver kappa statistic and correlation coefficient were estimated.Results: A total of 32 angiographic studies (21 patients) were reviewed. Post-thrombolysis angiograms werereviewed from 11 patients who underwentintra-arterial thrombolysis in addition tothe 21 baseline studies. The correlationcoefficient for Qureshi grading schemewas 0.97 and 0.98 with or without subcat-egories respectively. There was stronginterobserver agreement for Qureshi grading without subcategories {kappa =.88, weighted kappa=.94 (95% confidenceinterval [CI], .75 to .1)} and with subcate-gories {kappa = .81, weighted kappa=.93(95% CI, .33 to .81)}. The interobserveragreement for TIMI grading scheme wasgood {kappa = .731, weighted kappa=.94(95% CI, .51 to .95)}.Conclusions: Interobserver agreement for the Qureshi classification scheme forassessing severity of arterial occlusion isvery high and better than TIMI gradingscheme. This new six grade scheme mayallow better angiographic evaluation ofperfusion changes in the future.

123. Validity of ICD-9 Procedure Codes andCPT Codes for Thrombolysis in Patientswith Ischemic StrokePansy Harris-Lane, NP; Faisal Siddiqi, BS;Jawad F. Kirmani, MD; Adnan I. Qureshi, MD(Newark, NJ)

Introduction: Recently, new InternationalClassification of Diseases Ninth Revision(ICD-9) procedure codes and CurrentProcedural Terminology (CPT) codes weredesignated for injection or infusion ofthrombolytic agents. Although the intro-duction of ICD-9 and CPT codes allow estimation of national and regional use forischemic stroke, the accuracy of thesecodes is unknown. Methods: We determined the accuracy of ICD-9 procedure code 99.10 and CPTcodes 37201 and 37202 for use of throm-bolytics in a consecutive series of patientsadmitted to University Hospital for ischemicstroke over a 12 month period. The sensi-tivity, specificity, positive and negative predictive value of ICD-9 and CPT codeswere determined in comparison with aprospective registry maintained to ascer-tain use of thrombolytics in patients withischemic stroke.Results: Intra-arterial or intravenousthrombolytics were used in 51 (12.3%) of

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P OSTER PRESENTATION ABSTRACTSthe 415 patients with ischemic stroke.The sensitivity, specificity, positive andnegative predictive value of ICD-9 code99.10 for identifying use of thrombolyt-ics was 53%, 99%, 84%, and 94%,respectively. The sensitivity, specificity,positive and negative predictive valueof CPT codes 37201 and 37202 foridentifying use of thrombolytics was53%, 100%, 100%, and 94%, respec-tively. When ICD-9 or CPT codes wereused to identify use of thrombolytics,the sensitivity, specificity, positive andnegative predictive values were 84%,99%, 90%, and 98%.Conclusions: The use of ICD-9 andCPT codes alone may underestimatethe use of thrombolytics using nationaland regional databases. Best resultsare achieved when combinations ofICD-9 and CPT codes are used to iden-tify the use of thrombolytics.

124. Initial Experience With Drug ElutingStents for Symptomatic IntracranialStenosisAdnan I. Qureshi, MD; Jawad F. Kirmani,MD; Pansy Harris-Lane, NP; Afshin A.Divani, PhD (Newark, NJ)

Introduction: Drug eluting stents havebeen shown to reduce restenosis in coronary de-novo lesions. Results ofthe Stenting in SymptomaticAtherosclerotic Lesions of Vertebraland Intracranial Arteries study havereported that a high rate of restenosisis observed with intracranial stentplacement, suggesting a potential rolefor drug-eluting stents. To report thef e a s i b i l i t y, safety, 1-month and 6-monthresults of treatment of intracranialstenosis using drug eluting stents. Methods: Rates of technical success(defined as successful deployment ofstent at target lesion) and 1-monthmajor stroke (defined as a new strokewith National Institute of Health StrokeScale score greater than or equal to 4)or death in patients with symptomaticintracranial stenosis, any stroke, tran-sient ischemic attack, and angiographicrestenosis were determined.Results: Technical success wasachieved in 10 of the 11 patients. The10 patients were treated with sirolimuseluting stent (n=6) or paclitaxel elutingstent (n=4). Mean age was 57 plus orminus 19 years, 4 men. Stenosis waslocated in the following arteries: inter-nal carotid (n = 5), proximal middlecerebral (n = 2), vertebral (n=2), andbasilar (n=1). No major stroke or death

was observed at 1 month follow-up.Three patients suffered worsening ofpre-existing deficits with completerecovery observed in two at 1 monthfollow-up. Of the 5 patients that completed 6 month follow-up, 1 suffered a transient ischemic attack.Conclusions: The present studydemonstrates the feasibility of use ofdrug eluting stents for treatment ofsymptomatic intracranial stenosis.Further studies are required to deter-mine the effectiveness of drug elutingstents for intracranial stenosis.

125. Drug Eluting Stent Versus Bare MetalStent. Meta-Analysis of 13Randomized Trials. Implication forIntracranial Stent PlacementAdnan I. Qureshi, MD; Shafiuddin A.Ahmed, MD; M. Fareed K. Suri, MD; AfshinA. Divani, PhD; Jawad F. Kirmani, MD(Newark, NJ); M. S. Hussain, MD (Alberta,AB Canada)

Introduction: A search involving MED-LINE, PUBMED, and COCHRANE data-base was made for randomized clinicaltrials comparing drug-eluting stentswith bare metal stents for treatment ofcoronary lesions. Meta-analysis wasperformed using random effectsmodel. Outcomes compared included9-12 month rates of major adverse cardiac events including myocardialinfarction, death and total lesion revascularization, and angiographicrestenosis at 6-9 months. Methods: Thirteen trials including5752 patients were eligible accordingto our inclusion criteria and were ana-lyzed. Since significant heterogeneitywas indicated by Q statistics, we useda random-effects model to combine the data.Results: Compared with bare metalstents, drug eluting stents significantlyreduced the relative risk of a majoradverse cardiac event by 40% (relative risk [RR] 0.6, 95% confidence interval [CI] 0.4-0.8, p less than 0.001) inpatients with coronary lesions. Thebenefit was observed in reducing totallesion revascularization (RR 0.4, 95%CI 0.3-0.5), but not for myocardialinfarction (RR 1.2, 95% CI 0.8-0.8-1.8), death (RR 1.1, 95% CI 0.6-2.0) orstent thrombosis (RR 1.6, 95% CI 0.8-3.2). Among the 3869 patients withangiographic follow-up, drug-elutingstents reduced the relative risk ofrestenosis by 70% (RR 0.3, 95% CI0.2-0.4, p less than 0.001).

Conclusions: Compared to bare metalstents, drug eluting stents significantlyreduce the risk of major adverse cardiac events and angiographicrestenosis. Further studies are required to evaluate the feasibility and effectiveness of drug eluting stent forintracranial atherosclerosis lesions.

126. Bacteriology of Cerebral “Mycotic”Aneurysms Associated With InfectiveEndocarditis and the TreatmentOptions: 25-Year ExperienceVallabh Janardhan, MD (New York, NY);Madhu B. Vijayappa, MD; Christopher S.Ogilvy, MD; Bob S. Carter, MD; NeerajBadjatia, MD; James D. Rabinov, MD;Johnny C. Pryor, MD; Joshua A. Hirsch,MD; Guy Rordorf, MD (Boston, MA)

Introduction: Pathogenesis of intraca-nial infectious aneurysms(IIA) remainsunclear and septic embolization to the vasa-vasorum/lumen of cerebralvessels is a possible mechanism. In addition to antibiotics, surgical andendovascular therapies are available.We sought to understand the bacteriol-ogy of cerebral “mycotic” aneurysms inpatients with Infective endocarditis (IE)and the treatment options available. Methods: Charts of all patients withdischarge diagnosis of IE (ICD 9 code421.0) along with discharge diagnosisof subarachnoid hemorrhage (SAH)(ICD 9 code 430.0) or non-rupturedcerebral aneurysm (ICD 9 code 437.3)between 1/1979 and 2/2004 werereviewed to identify patients with IIA.48 charts were reviewed and patientswithout angiography were excluded. Results: 14 patients (Mean age 49years range 16-73 years; Men 71%,10/14) had IE associated with 18 IIA.Bacteremia occurred due toStaphylococcus aureus(n=6; 43%),Streptococcus viridans(n=4),Streptococcus sanguis (n=2),Streptococcus mutans(n=1),Cardiobacterium hominis (n=1), and enterococcus (n=1). Drug-resistantstaphylococci occurred (n=4). Septicemboli/ infarcts occurred (n=8;57%). Four patients had unruptured IIA andthe rest ruptured (n=10;71%) (SAHoccurred during hospital course in 4patients; 2/4 died). Location of IIAincluded middle cerebral artery(MCA)(13), posterior cerebral artery(4) and anterior choroidal artery (1).Four patients were managed medicallywith antibiotics alone. Surgical clip-

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ping/excision of IIA (n=5) and parentartery occlusion with glue embolization(n=3) for small distal MCA/PCA IIA afteramytal testing were performed. There wasno re-bleeding or any complications fromprocedures. Conclusion: IIA are commonly located inthe MCA and frequently rupture in patientswith IE. Staphylococci and streptococci arefrequently associated and antibiotic resist-ance to staphylococci is common. In addi-tion to appropriate antibiotics, if technical-ly feasible, serious consideration shouldbe given to surgical/endovascular treat-ments to avoid risk of rupture in this high-risk group.

127. Arteriographic Demonstration of SlowAntegrade Opacification Distal to aCerebrovascular ThromboembolicOcclusion Site as a Favorable Indicatorfor Intraarterial ThrombolysisGregory A. Christoforidis, MD; YousefMohammad, MD; Andrew Slivka, MD(Columbus, OH)

Introduction: This investigation sought todetermine whether slow antegrade con-trast opacifaction of an occluded cerebralartery distal to thrombus (clot outline sign)on cerebral arteriograms immediately priorto thrombolytic treatment is associatedwith higher recanalization rates. Methods: This study retrospectivelyreviewed the records and available imagesfrom 84 consecutive arteriograms per-formed prior to thrombolysis in patientseligible for intraarterial thrombolysis wherethe microcatheter was able to reach theocclusion site. The arteriograms werereviewed to identify whether contrast filledthe occluded vessel distal to the occlusionsite on the delayed images. This was thencorrelated to TIMI score using contingencyanalysis. Logistic regression analysis forTIMI score was performed which includedpresence of outline sign, age, site of occlu-sion, time to treatment, sex, and admittingglucose value.Results: Eighteen of seventy four arteriograms available for review displayedthe clot outline sign; of these 18 patientsthirteen (72%) went on to completelyrecanalize. Seventeen (30%) of 56 patientswithout demonstration of the clot outline sign went on to completely recanalize.Seventeen of 18 patients (94.4%) display-ing the clot outline sign were associatedwith a TIMI score of 2 or 3 whereas only31 (55%) of those without the clot outlinesign were associated with TIMI scores of 2or greater (p=0.0041). Logistic regression

analysis for TIMI scores relative to otherpredictors indicates that only the clot outline sign could act as a predictor forrecanalization (p=0.0008).Conclusions: Pre-thrombolysis arteriograms demonstrating delayed antegrade contrast opacification distal tothe occlusion site is associated with higher recanalization rates.

128. Motor Component of the Glasgow ComaScale- a Prognostic Indicator in High-Grade Aneurysmal SubarachnoidHemorrhage PatientsMontell D. Salary, MD; Matthew Quigley, MD;Brad Bellotte, MD (Pittsburgh, PA)

Introduction: Management of high-gradeaneurysmal SAH remains problematic.Mortality remains high with expendituresof resources on care, which may be futile.Part of the difficulty in prediction is theinherent limitations of the Hunt Hess grading system. We wondered whether themotor portion of the Glasgow Coma Scale(GCSm) might be of more predictive valuegiven its six points of discrimination. Methods: We retrospectively reviewedAllegheny General Hospitals admissionsbetween 1998-2002 for high-gradeaneurysmal SAH patients. Various treat-ments, physical exam findings, pre/postresuscitation (either life-threatening clotremoval or EVD placement) GCSm, time to intervention, medical history, length ofhospital stay, GOS scores at discharge,and radiographic elements were recordedwith outcome measured as survival at 6months.Results: There were 50 patients, 21males, and 29 females with an age range28-101. Forty-four patients received ven-triculostomies, six immediate clot evacua-tions. Employing a logistic regressionanalysis, post-resuscitation GCSm, HHgrade, and pupillary abnormalities correlatedwith outcome but age, presence of IVH,aneurysm type, time to intervention, cloton CT, and pre-resuscitation GCSm didnot. In the multivariate analysis however,only post-resuscitation GCSm remainedsignificantly related to 6 month survivalwith no survivors of GCSm 2 or less(9/50-18%) and only 11% (2-35% 95%confidence interval) of patients GCSm 4 or less alive at 6 months.Conclusions: Post-resuscitation GCSmappears to be the factor most predictive ofoutcome at 6 months. Management ofhigh grade SAH patients should includeimmediate ventriculostomy or clot e v a c u a-tion with reassessment of GCSm, followingwhich more accurate prognosis is possible.

129. Short-Term Results of Planned Volume -Staged Gamma Knife Radiosurgery forCerebral AVMS: Feasibility and ToxicityAditya S. Pandey, MD; Kevin M. Cockroft, MD,MSc; Carla Bruegel, BSN; Adam P. Dicker, MD,PhD; Erol Veznedaroglu, MD; Robert H.Rosenwasser, MD, FACS (Philadelphia, PA)

Introduction: Large cerebral AVMs locatedin high-risk surgical areas, continue topresent a challenge for radiosurgical treat-ment. We report our short-term results utilizing Gamma Knife radiosurgery in aplanned volume-staged approach to thetreatment of AVMs with a total volume ofgreater than six cubic centimeters. Methods: Eleven patients have beentreated in this manner with two stages ofsingle fraction Gamma Knife radiosurgery.Medical records and treatment plans wereretrospectively reviewed.Results: At time of first treatment,patients had undergone an average ofthree endovascular glue embolizations(range 0-6) and had a mean age of 37years (range 13 - 68). An average intervalof 20 plus or minus 4 months (range 10-42) elapsed between treatments. Mean initial and final treatment volumes were4.7 plus or minus 0.7 cubic cm and 4.6plus or minus 0.8 cubic cm. The averagedose prescribed to the 50% isodose linewas 20 Gy (range 19-22 Gy for first; 18-21Gy for second). At last follow-up (meanafter second stage 11 months, range 1-32months) there were no instances of mod-erate/ severe radiation toxicity and no new neurological deficits attributable toradiosurgical treatment. Five patients (45percent) did demonstrate evidence of mildradiation injury (MRI signal change with-out clinical symptoms). There were nointracranial hemorrhages in the follow-upperiod and all patients had a GlasgowOutcome Score of either four (4 patients) or five (7 patients).Conclusions: In conclusion, early evidence suggests that volume-stagedGamma Knife radiosurgery is feasible and safe for large cerebral AVMs. Futurestudies will evaluate for long-termradiotoxicity and efficacy of such a treatment protocol.

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P OSTER PRESENTATION ABSTRACTS130. Neurological Grade and age are

Associated With Volume ofAneurysmal SubarachnoidHemorrhageDavid S. Rosen, MD; Jocelyn Tolentino;Christopher Reilly, BA; R. Loch Macdonald,MD, PhD (Chicago, IL)

Introduction: Increasing volume of subarachnoid hemorrhage (SAH) pres-ent on the initial computed tomograph-ic (CT) scan after aneurysm rupture isstrongly correlated with the occurrenceof vasospasm and with poor outcome. Little is known, however, about factorsthat are associated with the volume ofSAH. The purpose of this study was toidentify such factors. Methods: Digital files of CT scans of75 consecutive patients admitted within24 hours of SAH were analyzed by ablinded observer using quantitativeimaging software to measure the volume of SAH. The length, maximumwidth in anteroposterior and lateralplanes and size of neck of the rupturedaneurysm were measured from admis-sion angiograms and corrected formagnification. Aspect ratios andaneurysm volumes were calculated.These variables, in addition to d e m o-graphic and clinical factors, were enteredinto uni- and multivariate analysis todetect associations with SAH volume.Results: Univariate analysis showedthat increasing initial SAH volume wassignificantly associated with increasingpatient age and worsening neurologicalgrade (p less than 0.05). In multivariateanalysis, only increasing patient ageand worsening neurological grade weresignificantly associated with SAH volume (p less than 0.05).Conclusions: These results are consis-tent with previous qualitative analysesof SAH volume that suggested thatolder and poorer-grade patients hadhigher SAH volumes. On the otherhand, an association with any measureof aneurysm size, as has recently beensuggested, could not be confirmed.

131. Endovascular Parent Vessel Occlusionto Treat Aneurysm Distal to P1Segment: Clinical OutcomeFrederick Vincent, MD; Alain Weill, MD;Daniel Roy, MD; Francois Guilbert, MD;Jean Raymond, MD (Montreal, PQ Canada)

Introduction: To determine the clinicaloutcome of patient harboring an aneury s mdistal to first segment of posteriorcerebral artery (P1), treated e n d o v a s c u-larly by parent vessel occlusion (PVO).

Methods: From 1989 to 2004, 11patients (8 female, 3 male; mean age44) were treated by PVO for aneurysmdistal to P1. Eight aneurysms weresaccular, and three fusiform. Threeaneurysms were giant and two large. In four cases the treatment was per-formed acutely following subarachnoidhemorrhage (SAH).Ten occlusions weredone using Guglielmi detachable coils(GDC). One was performed with glue (hystoacryl).R e s u l t s : The overall neurological complication rate (ischemic events) following PVO, was 6/11 (55%), with a permanent morbidity rate of 4/11(36%). However, clinical outcome was:Rankin 0 (7/11), Rankin 1 (3/11) andRankin 4 (1/11). Among the fourpatients with permanent deficit threewere treated acutely following SAH.Conclusions: Successful treatment ofaneurysms distal to P1 can be achievedby endovascular PVO. Complicationrate might be higher then previouslyreported (1), however long term clinicaloutcome is good. As suggested in thissmall series, aneurysms treated byPVO in acute phase of a SAH mighthave more ischemic events. (1) PaulHallacq, Michel Piotin, and JacquesMoret. Endovascular Occlusion of thePosterior Cerebral Artery for theTreatment of P2 Segment Aneurysms:Retrospective Review of a 10-YearSeries. AJNR 23:1128-1136, August2002

132. Incidence of Visual Field Defects inPatients With Occipital ArteriovenousMalformations Undergoing SurgicalExtirpationJulian Spears, MD, FRCS(C); MichaelTymianski, MD, FRCS(C); Toby Chan; M.C.Wallace, MD, FRCS(C) (Toronto, ONCanada)

Introduction: Arteriovenous malforma-tions of the occipital lobe compriseapproximately 15% of all brain AVMs.Surgical extirpation of occipital AVMsmay be associated with the onset ofnew visual field defects. The authorsreport their experience with 24 occiptalAVMs with respect to the associatedmorbidity of surgical extirpation. Methods: A cohort study was perf o r m e dbased on prospectively collected datafrom the University of Toronto AVMStudy Groups database, comprised ofall consecutively treated surgicalpatients possessing a brain AVM withina single center during a 12 year period.From this cohort, 24 surgically treated

occipital AVMs were identified (SM 1=6, II = 7, III = 8, IV = 3, V = 0). Primaryoutcome measures included the inci-dence of new visual field defects andpoor early functional outcomes followingsurgery. Secondary outcomes includedthe presence of permanently poor functional outcomes. Results: Of the 24 patients harboringoccipital AVMs reviewed, 33% (8/24),50% (12/24) and 16.7% (4/24) pre-sented with seizure, hemorrhage orwere considered incidental respectively.New visual field defects occurred in45.8% (11/24) post operatively ofwhich 13% of patients had a debilitat-ing outcome measured by RankinScore greater than 3 one week postoperatively. No patients had a perma-nently disabling outcome measured byRankin score greater than 3 at 1 yearpost surgery.Conclusion: Surgical extirpation ofoccipital AVMs remains a safe andeffective strategy in the treatment ofAVMs which needs to be evaluated withrespect to other treatment modalitieswith respect to the onset of new visualfield defects.

133. Endovascular Occlusion FollowingBypass for Giant or ComplexAneurysms: Indications and LessonsFrom 18 patientsNeil A. Martin, MD; Tarun Arora, MD (Los Angeles, CA)

Introduction: Giant and complexaneurysms requiring bypass followedby trapping or parent artery occlusionmay not be safely or effectively isolated by surgical means. However,endovascular occlusion may serve asan efficacious alternative. We reviewedthe senior authors (NAM) experiencewith such patients who underwenttherapeutic endovascular occlusion following bypass. Methods: Twenty-eight patientsbetween1985 and 2004 underwentbypass procedures combined withendovascular occlusion of theiraneurysm and/or parent artery. Tenpatients required a bypass afterendovascular intervention to manageischemia (5) or incomplete occlusion(5). Eighteen patients underwentbypass surgery prior to endovasculartreatment (4 failed balloon test occlu-sion, 1 failed carotid compression, and13 based on angiographic features).There were 13 anterior and 5 posteriorcirculation aneurysms, including 4 saccular (2 giant), 12 fusiform (8 giant,72

1giant-dissecting) and 2 semi-fusiform(1giant) aneurysms. Nine superficial tem-poral artery to MCA, 4 occipital artery toAICA or PICA, 5 saphenous vein interposi-tion, and 3 side-to-side bypasses wereperformed (2 patients had multiple grafts). Results: Using the Glasgow OutcomeScale, 66.7% had a good recovery, 16.7%had moderate disability, 11.1% had severedisability, and there was 1 death (5.5%)due to re-hemorrhage (average follow upperiod of 9.8 months). Complicationsincluded 2 post-operative hematomas(epidural, subdural), 2 CSF leaks, 2 cranialnerve palsies, and 1 bypass occlusion dueto infection. Complete aneurysm occlusionwas achieved in 14 of 18 patients. Conclusion: Endovascular techniques, inconjunction with bypass, provide a safeand effective alternative to surgical isola-tion of the aneurysm from the native circu-lation in otherwise unclippable aneurysms.

134. Inhibition of T-type Calcium ChannelsProtects Neurons From DelayedIschemia-Induced DamagePhilippe Bijlenga, MD, PhD; Mircea Bancila, MD;Irina Nikonenko, MD (Geneva, Switzerland)

Introduction: Intracellular calciumincrease is an early key event triggeringischemic neuronal cell damage. As thisincrease is largely attributed to the extra-cellular calcium entry, the role of calciumpermeable channels in ischemia is, tosome point, critical. However, implicationof T-type voltage gated calcium channels(or low-voltage-activated calcium chan-nels, LVAs) in neuronal response toischemia has never been studied. Methods: To study the possible role ofLVAs in delayed ischemic neuronal dam-age, we confirmed with immunochemistrythe presence of CaV 3.1 and CaV 3.2 typesof LVAs in rat hippocampus in vivo and inorganotypic slice cultures. Ischemic celldamage was studied using an in vitroischemia model in rat organotypic hip-pocampal slice cultures. The ischemic cell damage was quantified by propidiumiodide labeling of dead cells and sequentialmeasurements of the fluorescence at 2h,24h and 48h and compared to control cultures obtained from the same animaland observed on the same day.Results: Pharmacological inhibition of the T-type calcium current by more then80% with 10uM mibefradil or 500nM kur-toxin or 50 uM nickel during ischemia pro-vided a very significant protection againstdelayed neuronal death with less then 16%of PI positive cells compared to controls at48h after insult. Mibefradil exerted neuro-

protective effects not only if administratedduring the ischemic episode, but also inconditions of post-ischemic treatmentstarting as late as 3h after insult.Conclusions: These data suggest a possible new pharmacological approach to stroke treatment.

135. Extracellular Matrix AlterationsContribute to Cerebral VasospasmZhen-Du Zhang, MD, PhD; Elena Nikitina, PhD;Babak S. Jahromi, MD, PhD; MasatakaTakahashi, MD, PhD; R. Loch Macdonald, MD,PhD (Chicago, IL)

Introduction: Arteries that developvasospasm after aneurysmal subarachnoidhemorrhage (SAH) demonstrate reducedcontractility and compliance. Whetherthese changes are due to alterations in thesmooth muscle cells or the arterial wallextracellular matrix is unknown. This studywas designed to elucidate the location ofsuch changes. Methods: Dogs underwent creation of SAH using the double hemorrhage model.Vasospasm was assessed based on angio-graphy performed before and 7 days afterSAH. Vasospastic basilar arteries wereexcised (n=6-10 per measurement) andstudied under isometric tension in vitrounder normal conditions and after permeabi-lization of smooth muscle with alpha toxin.Endothelium was removed from all arteries.Results: Vasospastic arteries demonstratedsignificantly reduced contractility to KCl and prostaglandin F2alpha andreduced compliance that persisted afterpermeabilization (p less than 0.05 for eachcomparison). Calcium sensitivity was unaltered in vasospastic smooth musclealthough maximal responses were reducedin vasospastic arteries. Depolymerizationof actin with cytochalasin D abolished contractions to KCl but failed to alter arterial compliance.Conclusions: These results suggest thataltered calcium sensitivity does not con-tribute to maintenance of vasospasm afterSAH in dogs. Reduced compliance seemsto be due to an alteration in the arterialwall extracellullar matrix rather than thesmooth muscle cells since it cannot bealleviated by depolymerization of smoothmuscle actin.

136. Endoscope Assisted Microsurgery toCerebral AneurysmsTae-Sun Kim, MD; Je-Hyuk Lee, MD; Soo-HanKim, MD; Jae-Hyoo Kim, MD; Jung-Kil Lee,MD; Song-Pil Joo, MD; Shin Jung, MD; Sam-Suk Kang, MD (Gwang-Ju, Republic of Korea)

Introduction: The goal of surgical management of cerebral aneurysm is toexclude the aneurysm from the circulationwhile preserving the parent artery, itsbranches and perforator. To achieve thisgoal neuroendoscope is sometimes aneeded and useful tool. We describe thetechnique and advantages of neuroendo-scope in treating the cerebral aneurysms. Methods: Between September 2002 and February 2004, 51 patients with 57 cerebral aneurysms underwent microsurgical clipping with the help of theneuroendoscope. Rigid endoscope withdiameters of 2.7 or 4.0 mm and angles of30 or 65 degrees were used in all patients.Location of aneurysm were ICA in 37cases, ACA in 16 cases, MCA in 2 cases,superior cerebellar artery (SCA) in 2 cases.Results: Remnant aneurysm or compres-sion of surrounding arteries by clip weredetected by endoscopy in 15 cases andclips were repositioned or changed. In 13cases including 4 Pcom, 3 Acom, 3 ICAB,1 paraclinoid, 1 anterior choroidal artery,1 SCA aneurysm remnant aneurysm wasdetect and clips were repositioned orchanged. Compression of the branch byclip was observed along the aneurysmalneck in 2 cases with anterior choroidalartery aneurysms and clips were reposi-tioned to release the compression ofartery. There were no endoscope-relatedprocedural complications.Conclusions: Neuroendoscope is a safeand useful instrument to confirm the optimal position of the clip in the micro-surgery of cerebral aneurysm.

137. Covered Stents to Treat Traumatic andNon-Traumatic Vascular Lesions: PseudoAneurysms, Fistulas and AneurysmsFernando Gomez, MD; William Escobar, MD(Cali, Colombia); Sergio Vargas, MD (Medellin,Colombia)

Introduction: Demonstrate that coveredstents are an excellent treatment option forvascular lesions since they allow treatmentof the lesion while preserving the parentartery.Methods: During the period between June2000 and July 2004, a total of 16 patientswere treated: 15 male and 1 females withages 16-48 exhibiting the followingpathologies: Fistulas 7 (including carotid

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P OSTER PRESENTATION ABSTRACTScavernous fistulas, carotid vertebral fistulas, and carotid jugular fistulas); 7 pseudo aneurysms in the followinglocations: common carotid, carotidbifurcation, internal carotid and cav-ernous carotid and two paraclinoidincidental saccular aneurysms. Thematerials used were the following:Covered Stents: Jostent stent graft,Wallgraft and Stent Palmaz coveredwith autologous vein. Tri-axial cathetersystem, antiagregant therapy withClopidogrel/Aspirin. All procedureswere done under general anesthesia.Results: Morbi-mortality 0, neointimalhyperplasia 4/16, asymptomatic occlusion of the parent artery: 1/16.Minimum follow up was 3 months, andthe maximum follow up was 4 years.Clinically 15/16, with angiography14/16, with doppler duplex 4/16, without follow up 1/16.Conclusions: The treatment with covered stents is a safe technique, withexcellent results; it allows the preserva-tion of the parent artery healing thelesion. It is indicated for lesions belowthe anterior choroidal and posteriorcommunicating arteries. Neointimalhyperplasia was not hemodynamicallysignificant.

138. Characterization of avb3 Expression inVascular MalformationsMichael Lim, MD; Samira Guccione, PhD;Terri Haddix, MD; Hannes Vogel, MD;Pauline Chu, BA; Gary Steinberg, MD, PhD(Stanford, CA)

Introduction: Alpha V Beta 3 (avb3) is an integrin that has been shown to bespecifically expressed on endothelialcells of CNS neoplasms. However, nodata exists on the expression of theintegrin avb3 in CNS vascular malfor-mations. Here we investigate theexpression of avb3 in arteriovenousmalformations (AVMs) and cavernousmalformations. Methods: Frozen samples of AV M sfrom 12 patients and cavernous malfor-mations from 5 patients were obtainedi n t r a o p e r a t i v e l y. Once final pathologywas confirmed, immunohistochemistrywas performed using an avb3 mono-clonal antibody. The avb3 expressionpattern was graded as the percentage ofpositively staining vessels.Results: 10 out of 12 AVMs stained positively for the avb3 integrin. 6 of the10 positive samples stained moderatelyor strongly. Of the 6 samples, 5 camefrom patients 22 years of age or younger

and 4 samples came from patients whoreceived prior embolization. None ofthe cavernous malformations testedpositive for the avb3 antibodyConclusions: avb3 may contribute tothe vascular formation of AVMs. avb3may also provide a potential target fortreating AVMs. The lack of avb3expression in cavernous malforma-tions, despite their high vascular densities, suggests an alternativepathophysiology in the formation ofcavernous malformations.

139. Incidence of Stent AssociatedPseudoaneurysm in Patients who Were Treated With Neuroform Stentfor Intracranial Aneurysm - A SingleCenter ExperienceAbutaher M. Yahia, MD (East Lansing, MI);Vickie Gordon, RN, MS, NP; Richard D.Fessler, MD (Detroit, MI)

Introduction: Neuroform stent, a micro-cather delivery stent, which hasbeen approved for the treatment ofwide neck intracranial aneurysm. Thefrequency of pseudoaneurysm associ-ated with neuroform stent is notknown. Objective of our study is toreport the rate of pseudoaneurysm formation after neuroform stent treatment for intracranial aneurysm Methods: Consecutive patients from July 2002 to June 2004, who under-went neuroform stent placement forthe treatment of intracranial aneurysm,were enrolled. Patients demographiccharacteristics including locations andtypes of aneurysm were collected.Additionally, the incidence of pseudoa-neurysm formation was collected. Datawas analyzed using statistical softwareSPSS version 11.5Results: Neuroform stent was suc-cessfully deployed in all (unruptured17, residual 4, recurrent 2, fusiform 3and pseudoaneurysm 1) except in 1/29(3%) patient (middle cerebral arteryaneurysm) due to the extreme curva-ture in the artery. The mean age ofpatient was 47 plus or minus 17 yearsand 25/29 (86%) was female.Pseudoaneurysm was observed in 2patients (4%) at the distal end of thestent. First patients developed pseudoaneurysm in 3 months after thetreatment of his left middle cerebralartery giant aneurysm. In second case,it developed in 6 months after thetreatment of basilar artery trunkaneurysm and continued to grow.Therefore, the second patient was

treated with a neuroform stent anddemonstrated no regrowth. Patientsdemographics, aneurysm location andstent size was not associated withpseudoaneurysm formationConclusions: Neuroform stent associated pseudoaneyrusm is notuncommon, which could be treatedwith neuroform stent. Neuroform stenttreated patients warranted a long-termangiographic follow-up.

140. The Development of an Animal Modelof Carotid Artery Stenosis in aHyperlipidemic SwineAkira Ishii, MD; Fernando Vinuela, MD;Ichiro Yuki, MD; Yuichi Murayama, MD (Los Angeles, CA)

Introduction: The utilization of carotidartery stenting as a therapeutic modali-ty for arteriosclerotic carotid stenosishas spurred our interest in developingan animal model to study biomolecular,anatomical and histological phenomenarelated to this disease. This study aimsto develop such an animal model in ahyperlipidemic swine. Methods: We utilized 12 Yucatan mini-swines of mixed sex with an initialweight of 20-30 kg. Each animal wasfed with high-cholesterol diet 2 weeksprior to a surgical procedure. Bothcommon carotid arteries were surgicallyexposed and approximately a 90%stenosis was created. This surgical lig-ation aimed at lowering wall shearstress, which has been proven to trigger an atherogenic process.Endothelial denudation was endovascu-larly performed in the same procedureby inflating and manipulating an oversized balloon over the carotidartery intima. Carotid arteries were harvested at different time points andhistologically evaluated using standardand special imuno-histochemicalstains.Results: The blood tests showedhypercholestemia with an average of913 plus or minus 248 mg/dl. Theangiography showed wall irregularity in the stenosed carotid arteries. Thehistological evaluation of the diseasedcarotid artery demonstrated similaratherosclerotic plaques, when comparing with post-endarterectomy specimens: fat deposition, intimalhyperplasia, calcification and intra-plaque hemorrhage.Conclusions: This swine animal modelreproduced histologically similar ather-osclerotic plaque in carotid arteries of

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swines, when compared with endarterecto-my specimens . This animal model of atherosclerosis can be used for basic sciences research of genesis and develop-ment of an atherosclerotic plaque as wellas the impact of therapeutic endovasculardevices on their growth and/or cure.

141. Radiological & Microsurgical Study of theParaclinoid Internal Carotid ArteryCormac G. Gavin, MB, BS, FRCS (Dublin 2,Ireland); Paul Brennan, MD (Dublin 9, Ireland);John Bannigan, MBBS, PhD (Dublin 2, Ireland);Daniel Rawluk, MB, BS, FRCS; John Thornton,MB, BS, FRCS (Dublin 9, Ireland)

Introduction: The aim of this radiologicaland microsurgical cadaveric study was to examine the paraclinoid ICA using conventional and experimental imagingtechniques and to validate our originalfindings by direct anatomic comparison ina cadaver model. Materials & Methods: Fifteen cadaverscomprised the study cohort. The experi-mental MR sequences comprised of: unen-hanced thin slice coronal heavily T2w, T2wsimulated flow using water and T1w postferrous oxide with reformatting. The samecohort underwent 3D CT angiographicimaging with reconstruction to visualizeosseous and vascular structures. All 15cadavers were injected with colored latexand underwent microsurgical dissection.Particular attention was focused on thetransition of the ICA from extra to intradural, the clinoid space, dural rings, theophthalmic artery and carotid cave. Theparaclinoid region was examined using thesurgical microscope and compared withthe reformatted MRI images and 3D-CTangiographic reconstructions. Results: Unenhanced T2w images weresuccessful in 86% ICAs, and were identi-fied as the optimal imaging technique forvisualization of the transition of the ICAfrom intra to extradural. 3DCT-A demon-strated the relationship of the ICA to theACP and skull base. Microsurgical dissec-tion of the specimens demonstrated theintracranial anatomy and the relationshipof the ICA and ophthalmic artery to thedistal dural ring. Successful imagingsequences correlated with the findings atmicrosurgery.Conclusion: Thin slice T2w coronal MRIwith reformatting is the optimal sequencefor visualizing the distal dural ring and paraclinoid ICA and is a useful adjuvant toconventional imaging in the multidiscipli-nary management of paraclinoid arteryaneurysms.

142. Developmental Venous Anomalies: DoesAbnormal Perfusion Predispose toParenchymal Complications?Howard A. Rowley, MD; John K. Park, MD;Aquilla S. Turk, DO; George C. Newman, MD,PhD; Robert J. Dempsey, MD (Madison, WI)

Introduction: Developmental venousanomalies (DVAs) are seen as presumedincidental findings in approximately 3-5%of all patients receiving gadolinium forbrain MRI. Most DVAs show normal surrounding parenchyma, but some show evidence of adjacent gliosis, calcification,or an associated cavernous malformation.We hypothesize that perfusion studiesmight help characterize blood flow dynamicswithin DVAs, and that this informationmight be helpful in understanding thephysiology of parenchymal complicationsassociated with these lesions. Methods: Nine adult patients with developmental venous anomalies werestudied. Parenchymal MR images andgadolinium-enhanced MR perfusion examsincluding mean transit time (MTT) and relative cerebral blood volume (CBV) mapswere analyzed.Results: DVAs were most often observedin deep white matter or cortex of the cere-bral hemispheres (n=7), with 1 each in thethalamus and cerebellum. Abnormal perfu-sion was seen in 8 cases, with prolongedMTT in 8, elevated CBV in 5, reduced CBVin 3, and normal CBV in one. Associatedparenchymal findings included gliosis in 6,a cavernous malformation in 2, and hemo-siderin staining one. Perfusion changeswere typically more extensive than theassociated parenchymal lesions, suggestingthe functional disturbance was not simplydue to gliosis or tissue loss alone.Conclusions: 89% of DVAs showed abnor-m a l perfusion and 78% had associatedparenchymal lesions. We speculate thatprolonged transit times reflect venous outflow restriction leading to chronicvenous ischemia, gliosis, and sometimeshemorrhage. Larger longitudinal studiesare needed to define the incidence of perfusion abnormalities in DVAs and anyassociated risk of future parenchymalcomplications.

143. Delayed Blindness After HydroCoilEmbolization of Paraclinoid AneurysmsEdwin J. Cunningham, MD; Peter A.Rasmussen, MD (Cleveland, OH)

Introduction: HydroCoil, a hydro gel coat-ed coil that expands in biologic tissue, hasbeen shown in animal and human studiesto provide substantially higher volumetric

packing of saccular aneurysms than non-expanding coils. We report two cases ofaneurysms adjacent to the optic nerve that were coiled with HydroCoil and com-plicated by delayed onset of blindness. Cases and Intervention: A 52 year oldwoman presented with an asymptomatic 14mm left internal carotid artery aneury s mprojecting superiorly into the suprachias-matic cistern. She underwent embolizationof the aneurysm with HydroCoil and bareplatinum coils and was discharged home.She represented with ipsilateral monocularblindness 36 hours after the procedure.Repeat angiography showed the ICA andophthalmic arteries to be widelypatent with no evidence of intraluminalthrombus. MRI confirmed compression ofand signal change within the left opticn e rve. The second case involved a 69 yearold woman with a giant right ICA aneury s mand a baseline right homonymous hemi-anopia from a PCA infarct. Additionally,both optic nerves were compressed leavingher with poor baseline vision prior to treat-ment. She underwent embolization of thea n e u rysm with HydroCoil and bare platinumcoils and was discharged home. She repre-sented with binocular blindness and MRIrevealed increased mass effect from thecoiled aneurysm. Conclusions: While we lack definitive evidence that the complications were directly related to the use of the hydrogelcoated HydroCoil, the association cannot beexcluded. Based on these two cases, werecommend judicious use of expanding coilsin aneurysms adjacent to exquisitely sensi-tive structures, such as the optic apparatus.

144. Clinical Decision Analysis in theTreatment of Vasospasm AfterSubarachnoid HemorrhageCharles J. Prestigiacomo, MD (Newark, NJ);Charles Hunt, MD; Jeffrey Farkas, MD (New York, NY)

Introduction: Though numerous caseseries suggest that hypervolemic, hyperten-sive, hemodilution (HHH) therapy and/orangioplasty reduce post-vasospasm i n f a rction, randomized trials comparingthese therapies do not exist. Clinical decision analysis was used to objectivelycompare various treatments for vasospasmbased on current literature. Methods: A review for vasospasm treat-ment in subarachnoid hemorrhage wasperformed focusing on: natural history ofvasospasm; HHH outcomes; angioplastyoutcomes. Decision trees were createdoutlining different treatment algorithms:conservative management; HHH therapy;

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P OSTER PRESENTATION ABSRACTSHHH therapy followed by angioplasty;a n g i o p l a s t y. Utilities and quality-adjustedlife years (QALYs) were calculated foreach arm of the decision tree based. Asimple "roll-back" model was used todetermine which treatment algorithmwould benefit a patient withvasospasm. Sensitivity analysisassessed threshold values for whichthe benefits of one treatment algorithmoutweighed another.Results: Decision analysis suggeststhat angioplasty provides a higherprobability of good neurological out-come when compared to HHH therapyor conservative medical managementwith a difference of approximately 2QALYs. Sensitivity analysis was per-formed to assess the stability of thismodel with variations in several parameters (complication rates forangioplasty, complication rates forHHH therapy and their respective out-comes). These results suggest betteroutcomes for HHH therapy if complica-tion rates for angioplasty are greaterthan published literature and if HHHtherapy carries a very low complicationrate and a very high success rate. Conclusion: Angioplasty may improveoutcomes in patients with vasospasmwhen compared to HHH. Decisionanalysis is a tool that can allow clini-cians a method of comparing differenttreatment algorithms for a givenprocess.

145. Study of CCM1 Gene Mutations inChinese Intracranial CavernousMalformationsXie Rong, MD, PhD; Chen Cheng, MD, Prof(Shanghai, China)

Introduction: In past researchesintracranial cavernous malformations(ICM) has been approved to be ahereditary disease in nervous systemand the mutation of CCM1 gene(onchromas 7q11.2~22) is an importantcause of ICM. But mutation differencescan be found in familial ICM in varynations or areas. Among Chinese ICMpatients, the report of familial ICM wasvery infrequent. So our object is tostudy CCM1 gene mutations in ChinseICMs. Methods: 42 Chinese ICMs confirmed by pathological exam and 30 healthy individuals as contrast group were recruited. The peripheral venous bloodwere collected, from which DNAs wereextracted and exons of CCM1 genewere amplified by PCR. After purified

and cloned, the products were directlysequenced and the results were compared with GeneBank.Results: In exon 8, a frameshift mutation of 704insT was found in 2patients, which caused a terminalcodon earlier. In exon 12, a missensemutation of 1172CtoT was found in 10patients and an intronic mutation ofIVS12-4CtoT in 8 patients and an extramissense mutation of 1160AtoC inanother one patient. In exon 13, a missense mutation of 1405AtoC wasfound in 4 patients. In exon 17, a synonymous mutation of 1875CtoTwas found in 2 patients. In exon 18, aframeshift mutation of 2138insG wasfound in 1 patient. The rate of mutationof family ICMs was greater than sporadic ICMs(p less than 0.05).Conclusions: The mutation of CCM1gene in Chinese ICM patients is an impor-tant reason causing ICM which’s exist ineither family ICMs or sporadic ICMs.

146. Stereotactically Implanted tPAPolymers Effectively LyseIntraparenchymal Hematomas in aRabbit ModelQuoc-Anh Thai, MD; Gustavo Pradilla, MD;Federico Legnani, MD; Wesley Hsu, MD; Ryan Kretzer, MD; Rafael J. Tamargo, MD(Baltimore, MD)

Introduction: There is currently noadequate surgical treatment for sponta-neous intraparenchymal hemorrhage(IPH). Implantable polymers are analternative treatment that can effectivelydeliver therapeutic agents to the localsite of pathology, thus reducingadverse systemic effects. In this study,tPA polymers were used to induce lysisof IPH in a rabbit model. Methods: Ethylene-vinyl acetate (EVAc)polymers were loaded with bovineserum albumin (BSA) only or BSA plustPA, and the pharmacokinetics weredetermined in vitro by ELISA and spectrophotometry (n 9). For the efficacy study, rabbits (n 7) were fixedin a stereotactic frame and clottedautologous blood (0.1 ml) was injectedinto the right frontal lobe parenchyma.After 20 minutes, either control BSApolymers (n 3) or experimental BSAand tPA polymers (n 4) were stereotac-tically implanted at the hemorrhagesite. Animals were sacrificed at 3 daysand blood clot volume was assessed. Results: Polymers released tPA forover 72 hours. By day three, 7.3% ofthe tPA was released, yielding a total of

146ng of tPA released. Whereas rabbitsimplanted with control polymers hadan IPH volume of 23.7 plus/minus 6.8mm3 (mean p/m SEM; n 3), rabbitswith tPA polymers had significantlylower IPH volume of 1.3 p/m 0.1 mm3(mean p/m SEM; n 4; p 0.011). Conclusion: EVAc polymers release tPAover the course of 3 days. Stereotacticimplantation of tPA-loaded EVAc poly-mers significantly reduced IPH volume.Polymers loaded with tPA may be use-ful clinically for lysis of intraparenchy-mal hematoma without the side effectsof systemic administration.

147. Endovascular Reconstruction forTreatment of Intracranial AneurysmsWith a Novel Self-Expanding Leo-StentPedro Lylyk, MD; Juan Miranda, MD; AngelFerrario, MD; Leandro J. Haas, MD; BorisPabón, MD; Francisco Villasante, MD(Buenos Aires, Argentina)

Introduction: Endovascular treatmentfor cerebral aneurysms has becomewidespread. Many medical deviceshave been used and original devicesare constantly being introduced. Weherein report our initial experience intreatment of wide-necked intracranialaneurysms using a new LEO nitinolself-expanding stent (BALT extrusion,Montmorency, France). Material and Methods: Patients harboring wide-necked and fusiformsintracranial aneurysms were selectedfor a combined approach that consistedof delivery of a flexible new self-expanding neurovascular stent througha Vasco (BALT extrusion, Montmorency,France) microcatheter to cover theneck of the aneurysm and subsequentfilling of the lesion with coils throughthe stent mesh in saccular aneurysms .Patient records were analyzed for clinicalpresentation, location, type of v a s c u l a rdefect and size. Pre-procedural regimenof antiplatelet agents, procedure-relat-ed complications and adverse eventswere registered. Results: Twenty-one patients wereselected, aged 15 to 84 years. Therewas SAH in 8 (38%) cases and masseffects in 12(62%) cases. Segmentaldefect was documented in all of them.Technical success for stent deploymentin the parent vessel was 95,3 %. Two embolic events were registeredresolved with Reo-pro-without morbidity. Procedure-related morbimortality was 0%.

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Conclusion: In our experience, LEO self-expanding stent is a extremely flexibledevice, technically easy to deploy, that canbe readily and safely maneuvered throughseverely tortuous vessels, thus enablingthe treatment of intracranial side-wallwide-necked aneurysms. The combinationof endovascular reconstruction of the par-ent vessel by means of a stent followed bycoil embolization offers a promising thera-peutic alternative for lesions not amenableto coil embolization alone.

148. Efficacy and Safety of the Perclose CloserS Device Following NeurointerventionalProceduresKamran J. Khaghany, BS; Firas Al-Ali, MD;Thomas Spigelmoyer, RTR; Ron Pimentel, MS;Kurt Wharton, BS (Kalamazoo, MI)

Introduction: This study examines theefficacy and safety of the Perclose CloserS device versus manual compression forclosure of arteriotomy sites following neu-rointerventional procedures, in both virginand previously “Perclosed” vessels. Areview of the literature is also provided. Methods: A single-center, multiple-opera-tor, prospective controlled study was per-formed on 475 procedures in 337 patientswho received the Perclose Closer S 6Fdevice and 79 procedures in 79 patientswho received manual compression. A sub-stantial number of patients on anticoagula-tion and/or antiplatelet medications wereincluded. Efficacy and safety were evaluat-ed based on the rate of hemostatic success and incidence of clinically significant complications. A review of theliterature was performed using MEDLINE.Results: Overall success rate in the CloserS group was 95%, versus 96% in themanual compression group (p = 0.78).Overall clinically relevant complication ratein the Closer S group was 0.6%, versus2.5% in the manual compression group (p = 0.15). A statistically significant declinein success rates was seen only in vesselswith a history of 3 or more previous CloserS procedures; no significant change incomplication rates was found. The reviewof literature yielded 12 articles with com-plication rates ranging from 3.2% to 35%for the Perclose groups and 2.3% to33.3% for the manual compression groups.Conclusions: The Closer S was shown to be safe and effective for closure of arteriotomy sites in patients undergoingneurointerventional procedures, includingpatients on anticoagulation/antiplatelettherapy or with a history of two previoussame-vessel Closer uses.

149. Prevalence, Risk-Factors, and ClinicalCourse of Ruptured Intra-DuralDissecting Vertebral-Artery Aneurysms:Analysis of 28 CasesVallabh Janardhan, MD (New York, NY); MadhuB. Vijayappa, MD; Christopher S. Ogilvy, MD;Bob S. Carter, MD; Neeraj Badjatia, MD; JoshuaA. Hirsch, MD; Johnny C. Pryor, MD; James D.Rabinov, MD; Guy Rordorf, MD (Boston, MA)

Introduction: Pathologic case studies havesuggested that focal degeneration of theelastic fibers in the vessel walls rather thanatherosclerotic changes could play animportant role in the pathogenesis of intra-dural vertebral artery aneurysms (IDVA). Asthe prevalence of ruptured IDVA, their riskfactors and clinical course post-rupture arepoorly understood, we sought to study this. Methods: Charts of all patients with a discharge diagnosis of SAH between1/1994 and 2/2004 were reviewed to identi-fy patients with ruptured IDVA. Patientswith traumatic dissections were excluded. R e s u l t s : Among 1,398 SAH patients, a total of 28 patients(Mean age: 52 yearsrange 29-75years; Women: 11/28, 39.3%)had ruptured IDVA, a prevalence of 2.0%(28/1398). Atherosclerotic risk factorsincluded hypertension (n=9; 32.1%), current smoking (n=2), and diabetes (n=2).Carotid dissections/incidental aneury s m swere noted (n=6; 21.4%). Seizures(n=9;32.1%), hydrocephalus (n=22;78.6%),and vasospasm refractory to medical therapy (n=6;21.4%) frequently occurred.A n e u rysm locations were either proximalto posterior inferior cerebellar artery (PICA)(n=8), at level of PICA (n=6), supra-PICA(n=12), vertebro-basilar junction (n=1), or in the vertebral artery (n=1;no PICA).Treatments included conservative manage-ment (n=1), surgical trapping (n=2),endovascular proximal closure/trappingusing balloon occlusion (n=4), platinumcoils (n=18), or combination (n=3). Patientshad poor neurological exam post-SAH(Mean Hunt-Hess grade=3;range 1-5).Mortality in treated group was 25.9%(7/28). C o n c l u s i o n : Ruptured IDVA are relativelyuncommon but important cause of SAH(prevalence=2%). Spontaneous dissec-tions/incidental aneurysms are frequentlynoted in these patients suggesting that asystemic vessel-wall defect might play arole. Ruptured IDVA are associated withsignificant morbidity (seizures,hydro-cephalus,vasospasm) and mortality.Treatment-related mortality rates are significantly lesser than reported rates forc o n s e rvative management. Advances inneuro-critical care and technical develop-ments in endovascular therapy such as

stent-assisted coiling might help furtherimprove outcomes.

150. Systematic Review of Outcomes inPatients With Ischemic Stroke WithoutAngiographically DemonstratedOcclusions. A Case for Thrombolysis?M. S. Hussain, MD (Edmonton, AB Canada);Jawad F. Kirmani, MD; Adnan I. Qureshi, MD;Shafiuddin A. Ahmed, MD (Newark, NJ)

Introduction: The use of cerebral angiog-raphy is increasing in the acute stroke setting to document occlusions and offertherapeutic interventions. However, strokesmay occur without a demonstrable occlu-sion identified on angiography. Classically,patients in this situation are not treatedwith thrombolytics. Methods: To further elucidate the justification for not treating this group ofpatients, we performed a literature review.A search for pertinent articles using MED-LINE, PUBMED, and COCHRANE databaseswas supplemented by review of b i b l i o g r a-phies of relevant articles and personal files.Results: Three studies with 52 patientswere identified (32 males, 19 females, 1patients sex not identified). The averageage of the patients was 62 years. Thirty-five (67%) of the patients had an initialNational Institute of Health Stroke Scale(NIHSS) score less than 10, while seven of the patients (13%) had an NIHSS scoreless than 4. The average time to angiogra-phy was 220 (plus or minus 84) minutes.At 3 months, 29 (56%) patients had amodified Rankin Score of 0 or 1, indicatingfunctional independence. Neuroimagingreports of these patients often showednormal or small lesions.Conclusions: The outcome in patientswith ischemic stroke without angiographi-cally demonstrated occlusions appears tobe better than reported for patients witharterial occlusions. However, death anddisability are observed in a substantial proportion of these patients highlightingthe importance of developing furtherstrategies for acute treatment for thisgroup of patients.

151. Prospective Protocol for Managementof Hyponatremia in Non-TraumaticSubarachnoid Hemorrhage Patients With Hypertonic Saline (3%) InfusionVallabh Janardhan, MD; Igor Ougorets, MD;Jeffrey M. Katz, MD; David Wells-Roth, MD;Alan Segal, MD; Daniel M. Lahm, MD; HowardRiina, MD; Y Gobin, MD; Philip E. Stieg, PhD,MD (New York, NY)

Introduction: Hyponatremia occurs in30% of patients with non-traumatic

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P OSTER PRESENTATION ABSTRACTSsubarachnoid hemorrhage (SAH) and isreported to be associated withvasospasm. Natriuresis associated withelevated levels of brain natriuretic pep-tide has been postulated as a mecha-nism. We studied the safety/feasibilityof continuous intravenous (IV) infusionof 3% hypertonic saline (3% HTS) formanagement of hyponatremia in thispatient population using a prospectiveprotocol. Methods: All patients admitted to theneuro-intensive care unit (11/2003-8/2004) with non-traumatic SAH and who developed hyponatremia (serum sodium less than or equal to 35meq/L),were treated with continuous IV infu-sion of 3%HTS at rate of 1cc/kg/hourfor 2 weeks, during the vasospasmperiod. All patients had serum sodium(SNa) levels measured every 6 hoursduring therapy. The Glasgow comascales (GCS) were administered atadmission and discharge. Results: Among 48 patients with SAH,9 patients (Mean age:52.4 years; range:39-61 years;Men:5/9) with non-trau-matic SAH developed hyponatremiaand received 3% HTS. Mean Hunt-Hessgrade was 2.7 (range:1-4). Fisher gradewas 3 (n=9). Clinical vasospasmoccurred in seven patients (77.8%;n=7).The mean SNa level at admission =137.2 meq/L(range 132-142meq/L)and at discharge= 138.1meq/L (range131-144meq/L). The mean lowest SNalevel=131.4meq/ L(range 128-135meq/L) and mean highest SNalevel=146.3meq/L (range 136-156meq/L). There was good SNa control in all patients and none hadSNa less than or equal 130meq/L afterinitiating therapy. There was good out-come in 7/9(77.8%) patients. MeanGCS (admission) was 11.7 (range: 6-15) and mean GCS(discharge) was12.1 (range:6-15). There were no complications from 3%HTS and nomortality.Conclusion: Continuous IV infusion of 3% hypertonic saline for the manage-ment of hyponatremia in patients withnon- traumatic SAH is safe and feasi-ble. The efficacy of 3% HTS comparedto oral mineralocorticoids in thispatient population needs to be studiedin a controlled trial.

152. The Nitric Oxide Donor DETA-NOPrevents Vasospasm in a RabbitModel of SAH When Administered ina Delayed Fashion via ControlledRelease PolymersGustavo Pradilla, MD; Quoc-Anh Thai, MD;Federico G. Legnani, MD; Wesley Hsu, MD;Ryan M. Kretzer, MD; Paul P. Wang, MD;Rafael J. Tamargo, MD (Baltimore, MD)

Introduction: Depletion of periadventi-tial nitric oxide (NO) is a contributingfactor in the pathophysiology of cerebralvasospasm after aneurysmal subarach-noid hemorrhage (SAH). The NO-donordiethylenetriamine-NO (DETA-NO) prevents experimental vasospasm inanimals when administered immediate-ly after SAH. We tested the efficacy ofdelayed therapy with DETA-NO deliv-ered via controlled-release polymers inthe treatment of vasospasm in a rabbitmodel of SAH. Methods: Ethylene-vinyl-acetate(EVAc) polymers were loaded withDETA-NO (20% w:w). Rabbits (n=52)were randomized to two groups. Group1 (n=32) received SAH and either a20% DETA-NO/EVAc polymer (n=16)(DETA-NO dose = 0.5 mg/kg,) or emptypolymer (n=16). Polymer implantationswere done 24 (n=16) or 48 hours(n=16) after SAH. Group 2 (n=20)received SAH and either 20% DETA-NO/EVAc (DETA-NO dose = 1.3 mg/kg,n=10) or empty polymer (n=10).Implantations were done 24 (n=10) or48 hours (n=10) after SAH. Control animals (n=16) underwent either asham operation (n=6) or SAH only(n=10). Animals were euthanized 3days after SAH and the basilar arterieswere processed for morphometricanalysis. Statistical significance wasestablished using Students t-test.Results: Administration of 20% DETA-NO/EVAc polymers at 1.3 mg/Kg signif-icantly increased basilar artery lumen-patency when implanted 24(97 plus orminus 6% vs.73 plus or minus 10%,P=0.0396) or 48 hours (94 plus orminus 6%vs.71 plus or minus 9%,P=0.03) after SAH. Administration of20% DETA-NO/EVAc polymers at 0.5mg/Kg 48 hours after SAH significantlyincreased lumen patency (82 plus orminus 8% vs. 68 plus or minus 12%;P=0.0332). A dose of 0.5 mg/Kg, 24hours after SAH, did not reach signifi-cance (74 plus or minus 7% vs. 65plus or minus 9%; P=0.1602). Lumenpatency of the SAH-only group was 67plus or minus 12%.

Conclusions: Delayed administrationof DETA-NO polymers prevents cerebral vasospasm in rabbits in adose-dependent fashion. These find-ings support the role of NO-donors and controlled-release polymers in the treatment of vasospasm.

153. Endovascular Management ofCerebral Aneurysms: Our Experiencein Liverpool, UK With UnrupturedAneurysmsAjay K. Sinha, FRCS (Liverpool, UnitedKingdom); D. M. Nasser H .C., Nixon T E,Invent S, Foy P M and Shaw M

Introduction: We analyzed our experi-ence with endovascular treatment ofunruptured cerebral aneurysms overthe last 3 years (January 2001 toDecember 2003). Methods: Retrospective review andfrom September 2003 a prospectiveone of inpatient/outpatient clinicalrecords and imaging data.Results: 37 patients with unrupturedaneurysms were studied. They harbored 55 aneurysms. 290 patients with ruptured cerebral aneurysms weretreated during the same period of time.28 were females and 9 males with amean age of 49 years (range: 26 to 73 years). 7 (19%) had multipleaneurysms and 6 (16%) were greaterthan 20 mm.. 14 (38%) had previousaneurysmal SAH with clipped or coiledaneurysms. 2 were deteriorating fromaneurysmal mass effect. Intraoperativeaneurysm rupture was in 3 patients(8%) and parent vessel occlusion in 3(8%) and stenosis in 1 (2.7%). 5(13.5%) had new neurological deficitspostoperative. However, at dischargegood neurological outcome wasobtained in 33 patients (89%) with 2(5.4%) persisting with new neurologi-cal deficts postoperative. Another 2with preexisting neurological deficitsremained unchanged. Mean follow upwas 13 months. Radiological follow upwas undertaken using the base data onMRA immediate postoperative andcomparing this with repeat base MRAdata at regular intervals. Residualaneurysm filling was noted in 3 (8%) .There was no hemorrhage from treatedaneurysms.Conclusions: These unrupturedaneurysms represent some of the mostcomplex vascular problems and ourresults suggest a favorable outcome in 94% of such patients with endovas-cular surgery.

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154. Correlation of CT Angiography andTranscranial Doppler Sonography for theDetection of Vasospasm in AneurysmalSubarachnoid HemorrhageOsama O. Zaidat, MD, MSc (Morrisville, NC);Catalina Ionita, MD; James Eastwood, MD;Carmelo Graffagnino, MD; Michael J.Alexander, MD (Durham, NC)

Introduction: Transcranial Doppler (TCD)sonography is highly sensitive and specificmethod for detecting cerebral vasospasm(CVS) in subarachnoid hemorrhage (SAH).Recently, computed tomographic angiog-raphy (CTA) has been found to be sensitivemethod comparable with digital subtrac-tion angiography in detecting CVS. Thisstudy is designed to correlate CTA andTCD in detecting CVS in SAH patients. Methods: Twenty-eight patients with SAHunderwent CTA and TCD. We restricted the comparison between the two tests tostudies done within 24 hours of eachother. TCD vasospasm was defined asmild-to-moderate if peak mean velocity(Vp-m) was greater than 110 cm/s andmoderate-to-severe when Vp-m wasgreater than 160 cm/s). CTA-CVS wasdefined as present or absent when as readby neuroradiologist. Accuracy analysis wasp e rf o r m e d to correlate CTA-CVS with twoTCD velocity ranges (greater than 10 cm/svs. greater than 160 cm/s). Maximum TCDvelocities were also compared between theCTA-positive and negative groups. Results: CTA was negative for CVS in 17patients, and positive in 11 patients. TheCTA positive patients had median Vp-m of171 cm/s compared to 76 cm/s for CTAnegative group (P less than 0.001).Specificity was 100% when Vp-m wasgreater than 160cm, however this was atthe cost of sensitivity (64%). At this rangethe positive predictive value was 100%and the negative predictive value was85%. Utilizing TCD Vp-mof greater than110 cm/s yielded sensitivity of 82% andspecificity of 88% with 82% PPV and 88% NPV.Conclusion: CTA and TCD had excellentcorrelation when patients had moderate tosevere vasospasm. Vasospasm was rarelypresent on CTA when patients had Vp-mless than 110cm/s.

155. Withdrawn

156. Carotid Artery Stenting, the Alternativefor Radiation Induced AtherosclerosisRafael A. Ortiz, MD; Robert H. Rosenwasser,MD, FACS (Philadelphia, PA);

Introduction: The presence of carotidartery stenosis secondary to radiationinduced atherosclerosis increases the riskof stroke. Carotid endarterectomy has ahigh morbidity in this patient population.We retrospectively analyzed our experiencewith angioplasty and stent placement inpatients with radiation-induced stenosis. Methods: From 1996 to 1999, 10 patientsunderwent 12 angioplasty and stentingprocedures and 1 underwent angioplastyalone. All patients had undergone radiationtherapy to the neck region for malignancy.All patients underwent transfemoral cere-bral angiogram with urokinase infusion atthe carotid bifurcation prior to angioplastyand stent placement (Palmaz, Wallstent,Smartstent). Patients were then continuedon antiplatelet agents prophylactically.Results: Follow-up ultrasound and/or computed tomographic angiography at a mean follow up of 30 months (16-56)revealed a total of 3 restenoses in 2patients (23%). One patient developed aretroperitoneal hematoma that stoppedafter heparin reversal with protamine sulfate, but required evacuation. Therewere no mortalities as a result of treat-ment. Restenoses were treated with angioplasty ipsilateral to the symptomaticside followed by anticoagulation in oneand anticoagulation alone in the other.To date, no patient has suffered a delayedstroke or TIA. Conclusion: We present a series of 13cases of carotid artery stenosis secondaryto radiation induced atherosclerosis, with amean follow up of 30 months. Carotidangioplasty and stenting seems to be asafe and efficacious, but not perfect, alternative to medical therapy in high risksurgical patients who have been exposedto focal radiation of the head and neck.

157. Treatment of Bilateral Aneurysms Using aUnilateral Craniotomy: Case SeriesQuoc-Anh Thai, MD; Gustavo Pradilla, MD;Rafael J. Tamargo, MD (Baltimore, MD)

Introduction: Patients with bilateral supratentorial aneurysms may benefit from surgical clipping of all aneurysms via a unilateral craniotomy. We report ourcase series of 44 consecutive patients with bilateral supratentorial aneurysmsconsidered for contralateral approachessince 1991. Methods: We analyzed our prospectivedatabase for those patients with angio-

graphically documented bilateral supraten-torial aneurysms and reviewed their operative data to determine the successrates for the contralateral approaches andthe reasons for failures of the procedure. Results: There were a total of 44 patientswho presented with bilateral supratentorialaneurysms suitable for a unilateral cran-iotomy. 21 patients (48%) had successfultreatment of all aneurysms via the plannedapproach; 20 had a GOS of 5, and one hada GOS of 4. There were 5 patients (11%)in whom the contralateral approach wasplanned, carried out, but the aneurysmwas not clipped because of poor visualiza-tion. These all involved the contralateralposterior communicating artery (PCoA)aneurysms. Nine patients (21%), all ofwhom presented with subarachnoid hem-orrhage (SAH), had a planned contralateralapproach that was abandoned because of edema. 9 patients (21%) had bilateralaneurysms theoretically amendable to theunilateral craniotomy and contralateralapproach, but it was not pursued due tothe complexity of either the ipsilateral (5)or contralateral (4) aneurysm. Conclusion: The unilateral craniotomy withcontralateral approach for treatment ofbilateral aneurysms was completed suc-cessfully in 48% of cases with good GOS.Careful consideration should be given topatients with SAH and edema, complexaneurysms, or contralateral PCoAaneurysms, which are difficult to visualize.

158. Surgical Treatment of Patients WithMultiple Aneurysms in one Stage SurgeryUsing Keyhole ApproachesEdgar Nathal, MD, DMSc; Francisco Lopez, MD(Mexico City, Mexico)

Introduction: Multiple aneurysms arepresent in 20% of patients harboring cerebral aneurysms. At present, differenttreatment strategies are considered: a)one-stage surgery for aneurysms on thesame side (axis), b) two or more surgicalstages for aneurysms at different arterialaxis and c), combined approach withendovascular therapy in one or morestages for aneurysms in 3 axis. Methods: We present our experience withone stage surgery for patients with multipleaneurysms using keyhole approaches.There were 20 patients harboring 55aneurysms, operated between September1999 to October 2003. Using the Hunt andKosnik scale nine patients were on grade1, eight patients in grade 2 and threepatients in grade 3. There were 17 femaleand 3 male patients with age ranging from45-76 years (mean 59.1 years). Twelvepatients had 2 aneurysms, four had 3, one

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P OSTER PRESENTATION ABSTRACTShad 4, two had 5 and one had 7. Fortyseven aneurysms were located at theanterior and 8 at the posterior circula-tion. Surgical technique was as follows:a) unilateral keyhole approach foraneurysms located in one vascularaxis, b) bilateral keyhole approach foraneurysms on two axis and c),bifrontal craniotomy with keyholeopenings for aneurysms in three axis.Results: Surgical results using theGlasgow Outcome Scale were: Grade 1(80%), grade 2 (10%), grade 3 (10%).There were no patients in grade 4 or 5.Conclusions: Treatment of multiplecerebral aneurysms in one-stage surgery is possible whenever thepatient is in good neurological gradeand no mass effect lesions are present.

159. Aneurysm Size and Associated RiskFactors for RuptureNils H. Mueller-Kronast, MD; AlejandroRabinstein, MD; Stacey Quintero, MD;Mohamad Ali Aziz-Sultan, MD; JacquesMorcos, MD; Roberto Heros, MD; AloisZauner, MD (Miami, FL)

Introduction: The annual risk for rupture of cerebral aneurysms is low,however recent reports suggest thatruptured aneurysm may represent adifferent pathology. We therefore com-pared the aneurysm size of ruptured tounruptured aneurysms and identifiedrisk factors associated with the rupture. Methods: 168 consecutive cases ofintracerebral aneurysms were admittedto our tertiary referral center between8/03 and 8/04. Ten patients with dis-secting aneurysms were excluded. Allaneurysms were treated by surgical,endovascular or combined treatmenttechniques. The aneurysm location,overall aneurysm size, the aspect ratioas well as other parameters were analyzed. Results: The mean age of all patientswas 54 years. 82 aneurysms wereunruptured, whereas 76 aneurysmsruptured acutely. The aneurysm locationinvolved the anterior communicatingartery (26%), posterior communicatingartery (22%), ICA (23%), MCA (19%),as well as the posterior circulation(6%) and others (4%). The meananeurysm size for ruptured aneurysmswas 6.2 plus or minus 2.5mm and 8.2plus or minus 4.3mm for unruptureda n e u rysms. 83% of anterior communi-c a t i n g artery aneurysms presented witha rupture, whereas 54% of posteriorcommunicating aneurysms, 33% of

MCA aneurysms, and 13% of ICAaneurysms ruptured. The assessmentof the aspect ratio in our series wasnot helpful to differentiate ruptured (1.6plus or minus 0.4) from unrupturedaneurysms (1.9 plus or minus 0.7). Conclusion: Ruptured aneurysms weresmaller compared to unrupturedaneurysm, but this was statistically notsignificant. Anterior communicatingartery aneurysms had a significanthigher risk of rupture compared to allother aneurysms. The aspect ratio inpredicting aneurysm rupture was notuseful. Further values are necessary tomore accurately predict aneurysm rupture in the future.

160. Stent Induced Cerebral ArteryStenosisEdgard Pereira, MD (Louisville, KY)

Introduction: The use of neurovascularstents for treatment of intracranialaneurysms has expanded the endovas-cular management of these lesions.Although reports have described theacute thromboembolic complications of the technique, nothing has been discussed about the risk of stent inducedarterial stenosis. We report our seriesof followed up neurostents demonstrat-ing the presence of arterial stenosis asadverse effect of this device. Methods: Angiograms were performedin 9 patients who underwent stentassisted coil embolization of unrup-tured intracranial aneurysms. Theembolization was carried on accordingto a standard protocol, including theuse of Plavix and aspirin before andafter the procedure.Results: There were 4 men and 5women with aneurysms located in theICA, ACom, PCA, basilar, and SCA. Thepost embolization period varied from 3to 8 months. The follow up angiogramsdemonstrated stenosis in the proximaland distal ends of the stents in 5 of the9 patients, more noticeable in the PCA,ACA and MCA. None of the patientshad symptoms attributed to the stenosis.Conclusions: Although pliableintracranial stents have made possibletreatment of aneurysms that otherwisewould be considerable unsuitable forendovascular approach, its use canlead to vessel stenosis. Oversizing thestent could be an explanation for thepost stenting stenosis. More data isneeded before generalization can bemade. However, it serves as an

indication that the indiscriminate use of intracranial stents may not be justifiable.

161. Vertebral Artery Injury in TraumaPatients With Cervical VertebralFracturesLee A. Burnham, MD; Edgard Pereira, MD;Rick Sherry, MD (Louisville, KY)

I n t r o d u c t i o n : Identifying trauma patientswith vertebral artery injury (VAI) ischallenging since many are initiallyasymptomatic. Diagnosis is pivotal toensure appropriate anticoagulation andto prevent posterior circulation stroke.Therefore, aggressive screening withcomputed tomographic angiography(CTA) and/or magnetic resonanceangiography (MRA) is performed.Approximately one-third of traumapatients with cervical spine fracture arereported to have VAI by conventionalangiography. This retrospective studyexamines the diagnosis and sympto-matology of VAI in trauma patients with cervical vertebral fractures at ourinstitution. Methods: A database search was performed for discharge diagnosis of cervical fracture in trauma patientsfrom 1/2001 to 1/2004. This group wasthen refined to also include a dischargediagnosis of vertebral artery injury.These patients charts were reviewedfor fracture type, symptomatology, andtreatment.Results: 606 patients were identifiedwith cervical fracture, of which nine(1.5%) had a discharge diagnosis ofVAI. Six patients presented with neckpain, two were asymptomatic, and onewas unresponsive. Cervical fractureswere noted at all levels and seven ofeleven fractures involved the transverseforamen. Five patients were dischargedon coumadin, one on aspirin and plavix,two without treatment, and one died.Conclusions: The diagnosis of VAIappears to be under-diagnosed at ourinstitution where CTA is the screeningmodality of choice. In comparison withcerebral angiography, CTA is consider-ably less sensitive, and 1.5-Tesla MRAeven more so. We anticipate that thenon- invasive diagnostic accuracy ofVAI will improve with the implementa-tion of a 3.0-Tesla magnet at our insti-tution.

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162.Qureshi Grading Scheme forAngiographic Occlusions Correlates With Favorable Outcome Following Intra-arterial Thrombolysis for AcuteIschemic StrokeM. Fareed K. Suri, MD; Jose I. Suarez, MD(Cleveland, OH)

Introduction: Qureshi grading scheme hasbeen recently proposed to evaluate theseverity of arterial occlusion in acuteischemic stroke with attention to occlusionlocation and collateral circulation. We testedthe prediction of outcome using this schemefollowing intra-arterial thrombolysis.Methods: The Qureshi grading schemeassigns a score from 0 to 5 on the basis ofocclusion site and collateral supply. Wedetermined the relationship between initialQureshi grading scale assessed from initialangiography and outcome in 45 patientswho underwent intra-arterial therapy foracute ischemic stroke. Favorable outcomewas defined by modified Rankin scale scoreof 0 or 1. The area under receiver operatingcharacteristics (ROC) curve was estimatedfor prediction of favorable outcome at discharge using the Qureshi scheme.Results: A total of 45 patients were evalu-ated (mean age 69; 26 were men). Therewas a significant association between initial Qureshi grade on angiography andfavorable outcome at discharge (Pearsoncoefficient 11.8, p=0.04). The area underROC curve for prediction of favorable outcome and Qureshi grades was 70%.The area under the ROC curve for patientstreated prior to and after 4.5 hours was66% and 74%, respectively. The areaunder the ROC curve for patients aged 65years or greater and less than 65 yearswas 67% and 86%, respectively.Conclusions: Qureshi grading schemecorrelated with outcome in patients treatedwith intra-arterial thrombolysis. We thinkthat incorporating information regardingsite of occlusion and collaterals is mostimportant in patients under 65 years andthose treated after 4.5 hours of symptomonset.

163. Cisternal CSF of SAH Patients InducesEndothelial Cytosolic Calcium Oscillationvia Endoplasmic Reticulum Ca2+- ATPaseand Inositol Triphosphate Receptor GatedCa2+ ChannelsWolfram Scharbrodt, MD, PhD; Claudia Schäfer,PhD; Dieter K. Böker, MD; Hans M. Piper, MD,PhD; Wolfgang Deinsberger, MD (Giessen,Germany)

Introduction: The delayed cerebralvasospasm after subarachnoid hemor-rhage (SAH) is apparently a multifactorialprocess, including dysfunction of f i b r o b-lasts, smooth muscle cells and endothelium.The aim of the present study was to inves-tigate whether cisternal ceobrospinal fluidis able to influence the endothelial cytoso-lic Ca2+ concentration after SAH. Methods: As an experimental modelHUVEC (human umbilical cord veinendothelial cells) were incubated with cisternal cerebrospinal fluid (CSF) of 8patients with SAH. Four of these patientshad cerebral vasospasm. In control experi-ments we used native CSF. HUVEC wereloaded with the fluorescence Ca2+ indica-tor FURA-2. The emitted fluorescence lightwas collected with an inverted microscopeattached to a video imaging system.Results: Incubation of HUVEC with SAH-CSF provoked cytosolic Ca2+ oscillationsin 6 of 8 cases. After perfusion with CSFsampled from patients with cerebralvasospasm (n=4) endothelial Ca2+ oscilla-tions appeared immediately in all cases.The oscillation frequency was 0,27±0,016min-1 (mean value plus or minus SEM;n=44 cells). In the presence of tapsigarginan inhibitor of endoplasmic reticulum (ER)Ca2+--ATPase, the oscillations ceased inall cases. In further experiments the ER inositol-triphosphate (IP3) receptorgated Ca2+-channels were blocked byxestospongin. This leads to a significantdose-dependent reduction of the Ca2+oscillations-frequency. In control experi-ments with native CSF no oscillations wereobserved (n=8).Conclusions: Cisternal SAH-CSF, especial-ly from patients with cerebral vasospasms,is able to induce endothelial cytosolic Ca2+oscillations. These oscillations can beblocked by tapsigargin and reduced in frequency by xestospongin. This indicatesthat the oscillations are dependent on the function of ER Ca2+--ATPase and IP3receptor.

164. Cortical EEG (cEEG) Monitoring DuringIntracranial Vascular SurgeryAmir R. Dehdashti, MD; Damien Debatisse,PhD; Jean Guy Villemure, MD, FRCS; LucaRegli, MD (Lausanne, Switzerland)

Introduction: The aim of this study was todetect a neuronal threshold of tolerance toischemia by cEEG. The feasibility of simul-taneous continuous cEEG and scalp EEGduring intracranial vascular surgery wastested.

Methods: Twenty patients were monitoredby Scalp EEG and cEEG peroperatively.Seventeen patients had one or multipleanterior circulation aneurysms, 2 had anarteriovenous malformation and oneunderwent STA-MCA revascularization.Scalp electrodes were positioned onfrontal and centroparietal regions. After the craniotomy, three subdural electrodes,were placed on frontal, temporal and parietal cortex. Simultaneous recording ofscalp EEG and cEEG was performed duringthe surgery.Results: Excellent scalp and cortical EEGrecordings were obtained. During tempo-rary clipping of the middle or anteriorcerebral artery, 6 patients presented focalmodifications of the cEEG pattern thatwere not detected on scalp EEG. The mostcommon anomaly on cEEG was the highfrequency waves (Beta 3).These high frequencies were followed by slow waves(delta) and Burst EEG pattern suggestingneuronal ischemia. Corticographic changesresolved in all after clip removal. Nopatient presented symptoms or signs ofcerebral ischemia related to the temporaryclipping.Conclusions: The cEEG is easy to performand is more sensitive and specific than thescalp EEG. The specific cEEG pattern (highfrequency signals) described here, mightsuggest precocious neuronal ischemia.Future studies could provide additionalinformation on the real clinical value ofthis technique. A better comprehension ofthese anomalies could determine the dura-tion of the temporary clipping and conse-quently the surgical strategy.

165. Predictors of Hemodynamic ChangesAssociated With Carotid ArteryAngioplasty and StentingOsama O. Zaidat, MD; Ali Zomorodi, MD; Fuhai Li, MD; Tony P. Smith, MD; Michael J.Alexander, MD, FACS (Durham, NC)

Introduction: Hemodynamic changes may be encountered during carotid arteryangioplasty and stenting (CAS). We pres-ent the predictors and the course of bloodpressure and heart rate changes duringCAS in 96 procedures. Methods: Initial baseline, lowest, and final heart rate and blood pressure werer e c o r d e d in 96 procedures. Bradycardiaand hypotension were defined as any dropin the initial heart rate greater than orequal to 20%. The use of vasoactiveagents or pacemaker was recorded.R e s u l t s : A total of 96 CAS were perf o r m e d.The average initial heart rate, systolic, anddiastolic blood pressures were: 73, 158,77 respectively, versus the lowest vitals of

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P OSTER PRESENTATION ABSTRACTS62, 119 and 69. The average heart rate,systolic, and diastolic blood pressuresat the completion of the CAS were: 74,139, and 66. The incidence of brady-cardia was 18%, but only 4 (4.2%)patients were severe enough to requireinitiation of vasopressors. The pre-placed transvenous pacemaker firedduring CAS in 3 patients only (3.1%.The majority of patients responded tomedical therapy alone; with atropine,aramine, ephedrine, or glycopyrrolate.The main predictors of bradycardiawere initial heart rate of less than 65(P-value = 0.002), pre-existing coro-nary artery disease (p-value = 0.04)and radiation induced stenosis (P-value= 0.07).Conclusions: Transient asymptomaticbradycardia and hypotension are frequent in patients undergoing CASand can be managed with prophylacticuse of vasoactive drugs at the time of angioplasty. Radiation inducedstenosis, pre-existing bradycardia andcoronary artery disease are predictorsof bradycardia during CAS.

166. The Cut Flow Index: An IntraoperativePredictor of the Success of EC-ICBypassSepideh Amin-Hanjani, MD; Xinjian Du,MD; Nada Mlinarevich, RN; Guido Meglio,MD; Meide Zhao, PhD; Fady T. Charbel, MD(Chicago, IL)

I n t r o d u c t i o n : There has been a resurgenceof interest in extracranial-intracranial(EC-IC) bypass for revascularization ofcerebrovascular occlusive disease. Weevaluated the utility of intraoperativeblood flow measurements in predictinggraft success after EC-IC bypass. Methods: A review of 51 cases of EC-IC bypass for flow augmentation inthe setting of cerebrovascular occlusivedisease was performed. In all cases,free flow from the cut end of the donorvessel, termed “cut flow” was measured intra-operatively with anultrasonic flow probe. Cut Flow Index(CFI) = cut flow (cc/min)/ bypass flow(cc/min) was derived, and correlatedwith bypass patency, postoperativebypass flow measured by phase contrast magnetic resonance angiography (PCMRA) and cerebrovascular reserve testing.Results: CFI was a significant predic-tor of bypass patency (P=0.002). Using CFI of 0.5 as a threshold, bypasspatency rate was 92% in cases withCFI greater than 0.5 compared with50% in cases with CFI less than 0.5.

Intraoperative bypass flow correlatedwell with postoperative measurementsobtained from PCMRA. An analysis ofcases with poor CFI indicated that alogical interpretation of bypass functioncan be performed, and problems withthe donor /recipient vessel or anasta-mosis can be identified intraoperatively.Furthermore, patients with loss ofvasoreactivity on preoperative cere-brovascular reserve testing were morelikely to demonstrate a CFI close to 1.0(1.05 plus or minus 0.36 vs. 0.80 plusor minus 0.38, P=0.06).Conclusions: A poor CFI can alert sur-geons to potential difficulties with thedonor vessel, anastamosis, or recipientvessel intraoperatively. Furthermore, aCFI closely approximating 1.0 providesphysiologic confirmation of impairedcerebrovascular reserve in the recipient bed.

167. Primary Stenting of the VertebralArtery Ostium for SymptomaticStenosisSaumil Shah; Firas Al-Ali, MD (Kalamazoo, MI)

Introduction: The efficacy and safetyof vertebral artery ostium primarystenting for symptomatic stenosis hasnot been well-described. We presentour results of stenting 16 patients with 17 vessels. Feasibility, safety, andfollow-up patency are evaluated. Methods: 16 symptomatic patients (9 male, 7 female) with 17 vesselswere treated with primary stenting forvertebral artery ostium atheroscleroticstenosis, ranging from 75-99 percent.12 patients were symptomatic withprior transient ischemic attacks of theposterior fossa, and 4 patients present-ed with an acute stroke in the sameterritory. 15 of 17 vessels receivedheparinized stents (Hepacoat Bx;Cordis), and 2 received drug-elutingstents (Taxus; Boston Scientific). Afterevery intervention, a three monthangiographic follow-up was obtained.Results: All stents were successfullydeployed without immediate complica-tion and with less than 5 percent residual stenosis. 4 of 16 patients died,none attributed to the stenting. 5patients were lost to follow-up, including the 4 deceased patients, and1 patient still awaiting follow-up (6patients and 7 vessels total). Of the 10 remaining patients, 7 had no angio-graphic restenosis at 3 months, and 3with Hepacoat stents required furtherangioplasty to achieve complete

patency (30 percent restenosis rate). 1 patient required 2 consecutive angio-plasty procedures at 3 month intervals.Conclusions: Stenting of the vertebralartery ostium is both feasible and safe.Due to the high restenosis rate, follow-up angiography should be performed at 10-12 weeks. If stenosis is found,in-stent angioplasty could be per-formed, which is both safe and effective. Drug-eluting stents shouldhave a lower restenosis rate.

168. Hypothermia Attenuates the Decreasein Phosphorylation of Proteins in AKTCell Signal Pathway After PermanentMiddle Cerebral Artery Occlusion in RatsHeng Zhao, PhD; Takayoshi Shimohata, MD,PhD; Jade Q. Wang; Guohua Sun, MD, PhD;Midori A. Yenari, MD; Robert M. Sapolsky,PhD; Gary K. Steinberg, MD, PhD (Stanford, CA)

Introduction: AKT blocks apoptosis byphosphorylating substrates includingFKHR, and AKT is activated by growthfactors via a pathway that requires the kinases PI3K and PDK1. PTEN negatively regulates PI3K activity.We studied the effect of hypothermiaon phosphorylation (P) of PTEN, PDK1,AKT and FKHR after stroke. Methods: Stroke was induced byoccluding the left MCA permanentlyand both CCAs for 1 h in rats main-tained at 37 degrees C or 30 degrees C.Infarct size was measured 2 days later.Other groups were sacrificed at 30 minafter MCA occlusion and 30 min, 4, 8,24 and 48h after reperfusion. Thepenumbral area of the ischemic cortexwas dissected and cell homogenatewas prepared for Western blots.Results: Hypothermia reduced infarctsize. In normothermic animals, P-AKTdecreased during ischemia, increasedat 30 min and 4h after reperfusion, anddecreased after 8h. P-FKHR and P-PDK1 decreased after ischemia at alltime points. P-PTEN decreased from 30 min after occlusion to 8h post-reperfusion, recovered to pre-ischemiclevels from 24 to 48h. Hypothermia did not increase P-AKT at 30 min or 4h after reperfusion, but attenuated itsdecrease during ischemia and 8 h afterreperfusion. Decreases in overall levelsof P-PDK1 in hypothermic animalswere smaller compared to normothermia.P-FKHR increased at 30 min afterreperfusion and then decreased inhypothermic rats. Hypothermia blockedthe decrease in P-PTEN at all time points.82

Conclusions: Hypothermia may protect ischemic damage in part by pre-serving AKT activity and attenuating theapoptotic effects of PTEN, PDK1 andFKHR.

169. Aneurysmal Ruptures Presenting OnlyWith Intraparenchymal or IntraventricularHemorrhages: Case Series and LiteratureReviewQuoc-Anh Thai, MD; Shaan Raza, BS; GustavoPradilla, MD; Rafael J. Tamargo, MD (Baltimore, MD)

Introduction: An aneurysmal rupture typically presents with a subarachnoidhemorrhage (SAH), and it may concurrent-ly cause an intraparenchymal, intraventric-ular, or subdural hemorrhage (IPH, IVH, or SDH) in up to 34%, 17%, or 35% ofcases, respectively. In rare occasions,however, an aneurysmal rupture may present only with an IPH, IVH, or SDH without SAH. There are currently no seriesciting the incidence of this rare presentation. Methods: Using our prospective database,we analyzed those patients with rupturedaneurysms and reviewed their initial non-contrast head CTs, angiograms, and where applicable, post-operative head CTs.Patients whose initial presentation showedan IPH, IVH, or SDH in the absence of SAHon CT were identified. Results: 763 patients with documentedaneurysmal ruptures were admitted to The Johns Hopkins Hospital neurosurgeryservice from January 1991 throughSeptember 2003. Of these, 9 presentedwith an IPH only, 2 with an IPH and IVH,and one with an IVH only, for a total of 12 cases. There were 6 PCoA, 4 MCA, 1basilar apex, and 1 PCA aneurysm. Therefore,the incidence of aneurysmal rupture withIPH and/or IVH without SAH is 1.6%. Conclusion: Initial presentation of a rup-tured aneurysm without SAH is rare, andmay have a multi-factorial etiology due tothe timing of CT imaging, physiologicparameters, or location of the aneurysm.Patients presenting with initial head CTshowing an IPH in the temporal lobe withor without frontal/parietal involvementshould be considered for a work-up of aruptured aneurysm even in the absence ofdiffuse SAH.

170. Conditions of Protection by Hypothermiaon Apoptotic Pathways in a Model ofPermanent Middle Cerebral ArteryOcclusionHeng Zhao, PhD; Jade Q. Wang; Guohua Sun,MD, PhD; Midori A. Yenari, MD; Robert M.Sapolsky, PhD; Gary K. Steinberg, MD, PhD(Stanford, CA)

Introduction: Hypothermia is protective instroke models, but data from permanentocclusion models are conflicting. Weinduced focal ischemia in rats by perma-nent distal middle cerebral artery(MCA) occlusion to determine whetherhypothermia is effective in such cases. Methods: The left MCA was occluded permanently and the CCAs were reopenedafter 2 h, leading to partial reperfusion, in6 groups of rats maintained at 37C, 33C,or 30C during and for 2 h after occlusion(Group 1, 37/37; 2, 33/37; 3, 37/33; 4,33/33; 5, 30/37; 6, 30/30). Rats were sacrificed 2 d later to measure infarct size.Immunofluorescence staining was used todetect cytochrome c and AIF translocation.Results: Infarct sizes did not differ acrossgroups 1-3. Infarct size in group 4 wasreduced about 22% relative to group 1.When temperature was decreased to 30C(group 5) robust protection was observed;an additional 2 h hypothermia duringreperfusion in group 6 did not furtherreduce infarct size. Subcellular transloca-tion of cytochrome c and AIF in theischemic margin was not blocked by mildhypothermia (33C) in groups 2 or 3, butwas attenuated in group 4 and blocked ingroups 5 and 6, suggesting that apoptoticpathways are not blocked by mildhypothermia but may be blocked by moderate hypothermia (30C).Conclusions: Mild hypothermia is protective in a model of permanent MCAocclusion if it is extended well beyond theperiod of occlusion; short durations areprotective if temperature is lowered to 30C.

171. Aesthetic Defects of the Fronto-zygomaticFossa After Pterional Craniotomy can bePrevented Using a FrontozygomaticTitanium CranioplastyGustavo Pradilla, MD; Quoc-Anh Thai, MD;Federico G. Legnani, MD; Rafael J. Tamargo,MD (Baltimore, MD)

Introduction: Depression of the frontozy-gomatic fossa secondary to atrophy of the temporalis muscle results after frontosphenotemporal (FST) or pterionalcraniotomy. Proposed techniques forreconstruction of the temporalis musclehave failed to achieve consistent satisfac-tory results. We present the results of a

series of patients treated with FST craniotomy using a titanium cranioplastytechnique. Methods: FST craniotomies for eithera n e u rysm repair or tumor resection werep e rformed in 110 patients (107 cran-iotomies) between 3/27/02 and 7/30/04. Atthe end of the procedure a cranioplasty ofthe frontozygomatic fossa was perf o r m e dusing a titanium plate (figure 1), and thetemporalis muscle was attached to it (figure2). All patients have been followed (longestfollow-up of 2 years 3 months) to determinethe cosmetic results of the cranioplasty.Results: Outstanding cosmetic outcomeshave been obtained in all patients treatedto date. One patient developed orbital painand requested removal of the plate. Noother complications have been found.Conclusions: The characteristic depressionat the frontozygomatic fossa following FSTcraniotomies can be successfully preventedusing the frontozygomatic cranioplastywith outstanding cosmetic results.

172. eCLIPs Technology: A Novel Approach forEndovascular Treatment of IntracranialAneurysmsThorsteinn Gunnarsson, MD, MSc; BeipingQiang, MD (Toronto, ON Canada); Gyasi Bourne(Vancouver, BC Canada); Kenneth Pritzker, MD;Thomas R. Marotta, MD (Toronto, ON Canada)

Introduction: eCLIPs is a new devicedesigned to close intracranial aneurysmsat the neck without having to enter theaneurysm. It has two components, a “stentlike” anchoring device and a leaf portionwhich is held in place across the neck ofthe aneurysm in the parent vessel. Oncepositioned correctly, the device is deployedto deflect blood flow from the aneurysm.This changes the flow dynamics at theneck of the aneurysm and allows thrombusto form in the sac and neck healing tooccur. The objectives of the present studywere to test whether the eCLIPs device canbe navigated, oriented, safely deployed,and used to close experimental aneurysmsin an animal model. Methods: Eight experimental side wallaneurysms in swine were treated witheCLIPs. Results were assessed angio-graphically immediately and 30 days following treatment. The aneurysms aswell as the proximal and distal part of theparent vessel were analyzed byhistopathology.Results: All eCLIPs were successfullynavigated and deployed. Immediate closurewas observed in 4 aneurysms and nearocclusion with significant contrast stagna-tion in 4. On angiographic follow up allvessels were patent and all aneurysms

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P OSTER PRESENTATION ABSTRACTSwere closed. Histopathologic analysisshowed a constant pattern of healingwith smooth muscle cells growingacross the previous opening of theaneurysm.Conclusions: We have demonstratedthat eCLIPs can be navigated anddeployed successfully in an experimen-tal aneurysm model in swine. It causesimmediate closure or near closure ofthe aneurysm, keeping the parent vessel open, with healing response atthe neck of the aneurysm that is “surgical-like”.

173. How to Handle Small ArteriovenousMalformations in the SensorimotorAreaShokei Yamada, MD, PhD (Loma Linda,CA); Robert P. Iacono, MD (San Bernardino,CA); Javed Siddiqi, MD, PhD (Colton, CA);Austin R.T. Colohan, MD; Walter D.Johnson, MD; Frank P. K. Hsu, MD, PhD(Loma Linda, CA); Russell R. Lonser, MD(Bethesda, MD); George M. Mandybur, MD(Cincinnati, OH)

Introduction: Surgical resection ofarteriovenous malformations (AVMs) in the sensorimotor area is a contro-versial subject. Previously the authorsreported compartmental resection of large AVMs. The current paperdescribes surgical approach to smallAVMs in this eloquent area on 36patients. The patient presented withhemorrhagic episode(s) or seizures.AVMs were divided into group-1 (2 -3cm in diameter) and group 2 (less than2 cm). Group-1 AVMs showed angio-graphically demonstrable drainingvein(s) connected to the cortical veins.Group 2 often lacked this venous con-nection. Earlier, MRI and intraoperativesomatosensory evoked potentialsdetermined the sensory cortex and themotor cortex (by the phase reversal).Later, the sensory and motor areaswere identified by preoperativeMagnetic Source Imaging. AVMs wereresected without removing even tiniest amount of brain tissue around thenidus. Venous approach gained accessto the nidus in group 1 through thesulcus keeping sulcal cortex intact aspreviously described. Group-2 AVMswere reached by free-hand stereotaxydirected by color Doppler ultrasonogra-phy with a probe inserted through thecortex anterior to the motor strip orposterior to the sensory strip diag-onally under the sensorimotor cortex. A thin layer of brain tissue was

dissected around the probe to its tip,and then interruption of shunting arterioles and communicating venulescircumscribed the nidus. The resultswere overall excellent; all the patientsrecovered from surgery without neurological deficit or worseningdeficit, followed by seizure control. The authors conclude that well-plannedapproaches toward resection of thesesmall AVMs with meticulous techniquesare safe and benefit symptomaticpatients.

174. CT Perfusion for Detecting Changes inCerebral Perfusion Before and AfterStentingAnnet Waaijer, MD; Irene C. van der Schaaf,MD; Mattias van Osch, PhD; Evert-janVonken, MD, PhD (Utrecht, The Netherlands);Marcel Quist, MS (Best, The Netherlands);Birgitta K. Velthuis, MD, PhD; Maarten S.van Leeuwen, MD, PhD; Mathias Prokop,MD, Prof (Utrecht, The Netherlands)

Introduction: Purpose: To assesswhether CT perfusion can detectchanges in cerebral perfusion beforeand after carotid artery stenting. Methods: We scanned 13 patients withunilateral symptomatic carotid arterystenosis before and after primary stentplacement on a 16-slice scanner.Dynamic CT perfusion images wereacquired using two adjacent 12 mmslabs at the level of the basal gangliaduring the injection of 40 ml contrastmaterial. Perfusion images were reconstructed according to the centralvolume principle. On each of the twoslabs ROIs were drawn in the anterior,middle deep, middle cortical and poste-rior flow territories. For cerebral bloodvolume (CBV) and cerebral blood flow(CBF), we calculated the ratios ofmeasurements in the ROIs in theasymptomatic to symptomatic hemi-sphere and compared the ratios beforeand after stenting using a paired t-test.The same was done with the differencein MTT between the two hemispheres. Results: CBV ratios did not change significantly after stent placement. CBFratios increased in the middle corticalterritory from 0.78 to 0.90 (p= 0.001),in the middle deep territory from 0.80to 0.92 (p less than 0.001) and in theposterior cortical territory from 0.89 to1.03 (p less than 0.05). MTT differencedecreased from 2.40 to 0.22 (p lessthan 0.01), in the middle deep territoryfrom 1.06 to 0.36 (p=0.001) and in theposterior flow territory from 0.45 to

0.03 (p less than 0.005). Conclusions: CT perfusion is able to detect significant differences in CBFand MTT before and after carotid arterystent placement. The largest differ-ences are found in the middle corticaland deep flow territories.

175. Safety and Feasibility of Intra-thecalr-tpa for Intraventricular Hemorrhagein Patients With Secured RupturedAneurysmsVallabh Janardhan, MD (New York, NY);Christopher S. Ogilvy, MD; Madhu B.Vijayappa, MD; Bob S. Carter, MD; NeerajBadjatia, MD; Guy Rordorf, MD (Boston, MA)

Introduction: Intraventricular hemor-rhage frequently occurs following subarachnoid hemorrhage (secondaryIVH) and intra-thecal thrombolysis withr-tpa (IT-tpa) could decrease the clotburden in the ventricles and subarach-noid space and potentially decrease the need for ventriculo-peritoneal(VP)shunting and the risk of vasospasm.However, the safety and feasibility ofIT-tpa through extraventricular drains(EVDs) for the management of secondary IVH in patients with securedruptured aneurysms needs to bestudied. Methods: The charts of all patientswith a discharge diagnosis of SAH (ICD 9 code 430.0) between 1/1998and 2/2004 were reviewed to identifypatients with secondary IVH whounderwent IT-tpa. Head CT scans wereobtained 12 hours after each IT-tpadose and patients were monitored inthe neuro-intensive care unit. Results: Among 661 patients withaneurysmal SAH, a total of 5 patients(Mean age:69years;range 60-80 years;Men: 3/5) underwent IT-tpa for themanagement of secondary IVH. Allpatients had aneurysms secured priorto IT-tpa( Clip: 4/5; coil:1/5). Patientshad poor neurological exam (n=5 MeanmRS:5; Mean Hunt-Hess grade:4.8)and moderate/ severehydrocephalus(n=4) prior to initiatingtherapy. IT-tpa at doses 1-4mg/day wasadministered through the EVD q12hours (n=1) or q24 hours (n=4) for 2-5days (Mean: 3.8 days). There were nosignificant bleeding complicationsrelated to IT-tpa. There was no mortali-ty associated with the IT-tpa. Conclusion: Intra-thecal thrombolysiswith r-tpa through an EVD is a safe andfeasible therapy in selected patients

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with significant intraventricular and sub-arachnoid clot burden in whom the rup-tured aneurysms have been secured byclipping or coiling. Further prospectivestudies need to evaluate the efficacy of IT-tpa in preventing the need for VP shuntingand decreasing the risk of clinicalvasospasm.

176. Withdrawn

177. Pediatric Non-Vertebral ParaspinalArteriovenous Fistulas Along the NerveRoot: Clinical, Imaging, and TherapeuticConsiderationsYasunari Niimi, MD, PhD; Alex Berenstein, MD;Patricia M. Fernandez, MD; Jonathan L.Brisman, MD; Joon K. Song, MD (New York, NY)

Introduction: Paraspinal non-vertebralarteriovenous fistulas along the nerve rootare a rare and their clinical and radiologicalfindings and treatment methods are notwidely recognized. Methods: We identified five patients (age ranged 2 to 3 years) in our databasecovering 1985 to 2003 and performed ret-rospective review of the medical records,imaging, cardiovascular evaluations, spinalangiograms, treatment, and follow upresults.Results: All patients presented with anincidentally found continuous murmurauscultated over the upper paraspinal orparasternal regions. In four patients, theAV fistula was found in the mid-thoraciclevel and in one patient at L3. All AV fistu-las were high-flow single-hole fistulas atthe neural foramen with venous drainageinto paraspinal and epidural veins withoutreflux into the intradural perimedullaryveins. All fistulas were completely occlud-ed by endovascular embolization followingdiagnostic spinal angiography in the same session. The fistula was occluded withdetachable coils in one case and with N-butyl-cyanoacrylate (NBCA) liquidembolic agent in four cases. Prior to NBCAinjection, the flow through the fistula wasdecreased by placing detachable coils into the venous side in two cases and byinflating a balloon catheter in the proximalfeeding artery in two cases. All patientsremained neurologically normal withoutevidence of recurrence during the followup period ranging 6 to 156 months (mean63 months).Conclusions: Non-vertebral paraspinalarteriovenous fistula along the nerve rootis a specific disease entity seen in childrenpresenting with bruit and cardiomegaly.It is important to be aware of this rare disease for early diagnosis and treatment.

178. Evaluation of Plaque Morphology andDegree of Stenosis for EndovascularTherapeutic ProceduresAli P. Ebrahimi, PhD; Arshad U. Siddiqui, MD;Afshin A. Divani, PhD; Pinakin R. Jethwa, BS;Jawad F. Kirmani, MD; Adnan I. Qureshi, MD(Newark, NJ)

Introduction: Carotid occlusive diseasehas accounted for twenty-five percent ofstroke cases. In recent years carotid stentplacement has been investigated as analternative treatment for carotid stenosis.Currently, stent size selection is dependenton the degree and length of stenosis, as well as the diameter of the artery.Knowledge of plaque morphology wouldbe advantageous in determining themechanical forces involved in stent placement. We report the use of plaquemorphology as an alternative method forstent selection. Methods: Angiographic images of 20patients were examined for vessel sizemeasurements in the stenotic area. Usingimage processing software the degree ofstenosis and area of occlusion were determined.Results: Out of 20 patients examined, 6 were found to have between 50-60%stenosis with vastly different stenoticareas. The average degree of stenosis inthese patients was 56.76% plus or minus2.84, whereas the average stenotic areawas found to be 30.58% plus or minus7.37. Analysis of the data using pairedsample t-test showed a significant difference between the means with p less than 0.001.Conclusions: The data suggests that thedegree of stenosis alone does not providesufficient information for proper stentselection. Plaque morphology gives a better indication of the stent size thatwould provide the optimal force on thevessel wall. Future study needs to focus on the benefits of measuring plaque mor-phology for more accurate stent sizing.

179. Angioplasty of M2 Intracranial StenosesJawad F. Kirmani, MD; Pansy Harris-Lane,CRNP; Afshin A. Divani, PhD; Ammar AlKawi,MD; Nazli Janjua, MD; Adnan I. Qureshi, MD(Newark, NJ)

Introduction: Distal segments of the middle cerebral artery may be affected byatherosclerosis but are not consideredamenable to endovascular treatment. Wereport the feasibility, safety, and 1-monthresults of performing primary angioplastyfor symptomatic stenosis involving the M2segment of the middle cerebral artery (MCA).

Methods: We determined rates of technicalsuccess and 1-month major stroke ordeath associated with primary angioplastyusing 1.5 mm diameter balloon dilatationcatheters. Technical success was definedas successful angioplasty of the targetlesion. Major stroke was defined as a newstroke with National Institute of HealthStroke Scale score greater than or equal to4. Further outcomes ascertained includedany stroke, transient ischemic attack, andmajor adverse events. Results: Technical success was achievedin all 3 patients treated with primaryangioplasty. The mean age of the 7 treatedpatients was 69 years (range 52 to 88years) and included 4 men and 6 women.The device was successfully retrieved in allcases using a 4F catheter. One device hadmacroscopically visible debris. There wasno major stroke or death observed in the 1 month follow-up. Conclusions: The present study demonstratesthe feasibility of performing primary a n g i o-plasty for M2 segment stenosis of the MCA.Further studies are required to determinethe effectiveness of drug eluting stents forintracranial stenosis.

180. Intersubject Comparison of Time toTreatment Between Intravenous andIntra-Arterial Thrombolysis.Jawad Kirmani, MD; Adnan I. Qureshi, MD;Pansy Harris-Lane, CRNP; Ammar AlKawi, MD;Nazli Janjua, MD; Afshin Divani, PhD;Shafiuddin Ahmed, MD; Abu Nasar, MS(Newark, NJ)

Introduction: We measured intravenous(IV) versus intraarterial (IA) time treatmentintervals as part of a prospective studyevaluating safety and effectiveness ofmechanical clot disruption following intra-venous thrombolysis for ischemic stroke.Differences in time treatment intervalsbetween the two may have implications on clinical outcomes of the patients. Methods: Patients with National Institutesof Health Stroke Scale (NIHSS) of greaterthan or equal to 10 underwent emergentcerebral angiography (intent-to-treat) following administration of intravenousalteplase (0.9 mg/kg). Preparation for bothapproaches was initiated simultaneously.Time intervals were measured betweensymptom onset and administration ofintravenous alteplase (onset to needletime) and symptom onset and placementof microcatheter or balloon at occlusionsite (onset to catheter time). NIHSS wereperformed before treatment and at 24hours, seven to 10 days. Modified Rankinscores (mRS) were calculated at one tothree months post treatment.

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P OSTER PRESENTATION ABSTRACTSResults: Seventeen consecutivepatients were evaluated (mean age,65.4 plus or minus 13.8 yr; 9 weremen). Initial NIHSS scores ranged from12 to 21. The onset to needle and theonset to catheter times were 1:55hours and 3:42 hours respectively.Neurological improvement (decline ofat least 4 points in NIHSS score) wasobserved in 12/17 patients at 24 hoursand 11/17 at 7 days. Among those whodemonstrated improved NIHSS, theaverage onset to needle and averageonset to microcatheter times were 1:43hours and 3:33 hours respectively.Average IV tPA and microcathetertimes were 115 and 220 minutesrespectively (P=0.047).Conclusions: A significant differencewas observed between intravenous andintraarterial treatment times.

181. ALGEL, a Biocompatible Material forEmbolization of AVMs: Toxicology andSurvival Animal ResultsCameron G. McDougall, MD, FRCSC(Phoenix, AZ); Timothy A. Becker, PhD (Ann Arbor, MI); Mark C. Preul, MD;William D. Bichard (Phoenix, AZ); Daryl R.Kipke, PhD (Ann Arbor, MI)

Introduction: We assessed calciumalginate (ALGEL) for embolization ofswine AVM models for up to sixmonths, and performed extensive toxicology and intrathecal contact studies. ALGEL, a novel and biocom-patible embolization alternative, hasrecently passed all pre-clinical andFDA-mandated toxicity and mechanicalstability testing requirements for a clinical device. Methods: ALGEL and the reactive component, calcium chloride, wereinjected from approved concentric-tubemicrocatheters into the swine retemirabile (RM) after a carotid-jugularfistula was created in the neck to re-direct flow through the RM. A battery of ISO toxicology studies and a rabbit brain implant study furtherassessed ALGEL biocompatibility.Results: Angiography and histologyassessed occlusion stability in nineAVM swine models for up to sixmonths. A minor bioactive responsewas noted in the three one-month survival swine, yet no adverse immuneresponse or tissue damage was seen.At six-month survivals, the remainingswine showed endothelial and tissueencapsulation of ALGEL, stabilizing theocclusion. Intrathecal rabbit implants

and toxicology results showed noadverse reactions to ALGEL or its reactive component, calcium chloride. Conclusion: Pre-clinical animal and toxicology studies validated ALGEL asa permanent, stable, and biocompatibleembolization material that can maintainvascular occlusions in animals with no adverse tissue effects. This workcompletes pre-clinical assessment ofALGEL for embolization of AVMs. ALGELis one of a generation of exciting newbiomaterials that warrants clinicalassessment and will likely improveneuro-endovascular treatment options.

182. Use of the Arteriovenous OxygenDifference in Patients With CerebralArteriovenous MalformationsEdgar Nathal, MD, DMSc; Ernesto Ledesma,MD (Mexico City, Mexico)

Introduction: Cerebral arteriovenousmalformations (AVM) are congenitallesions with persistence of a directarteriovenous (A-V) fistula without acapillary network. On the other side,the venous oxygen saturation is a useful parameter to measure the balance between the distribution andconsumption of cerebral oxygen. Material and Methods: We performeda prospective study using the arteriove-nous oxygen difference (AVOD), aspredictor of total excision of an AVM.Twenty five patients were included inthis study. All patients underwentmicrosurgery. A venous catheter wasput in the internal jugular vein directedto the jugular bulb area on the side ofthe AVM. There were taken blood sam-ples from the jugular vein and radial artery simultaneously before andafter surgery. The oxygen saturationvalues were compared according to astandard equation for calculation of thearteriovenous oxygen difference. Thepre and postoperative values werecompared using a t student test.Results: The complete protocol wascompleted in 21 patients. In four casesthe catheterization was not technicallypossible. There were 13 female and 8male patients with ages ranging from15-45 years. In 19 patients, the AVMwas totally excised and in two of thema residual nidus was visible on postop-erative angiograms. The Oxygen differ-ence values of the total group showeda statistical significance (p less than0.05) when considered the pre andpostoperative period. When evaluatedby subgroups, four patients showed

borderline values (p less than 0.07)included the two with residual nidus.Conclusions: Our results support thephysiological concept of the A-V shuntobliteration after a total AVM excision.

183. Prediction of Survival and FunctionalOutcome After IntraventricularHemorrhage: Dependence on ageMarcus Luecke, MD; Marco Stein, Jr., MD;Wolfgang Deinsberger, MD; Dieter-KarstenBoeker, MD; Andreas Joedicke, MD(Giessen, Germany)

Introduction: It has been shown thatimmediately placed ventricular drainageimproved prognosis of intraventricularhemorrhage. Our aim was to define predictors of outcome with special emphasis on age. Methods: A homogenous group of 108 adult patients were all treated withintraventricular drainage after typicalintracerebral hemorrhages withinvolvement of the ventricular system.Regression analysis were performed to evaluate age, CT-morphological andclinical parameters as predictors forsurvival and functional outcome. Results: Only 4 of 69 (6%) patientsolder than 60 years achieved a GOS of4 or 5 compared to 12 of 39 (34%)patients younger than 60 years. Nopatient with an initial GCS score ofless than 9 had a favorable outcome.Univariate regression analysis showedsignificant correlation of hydro-cephalus, volume of the associatedintracerebral hemorrhage, midline shiftand ventricular blood distribution(LeRoux-score) as CT morphologicalparameters and initial GCS score toshort (30 days) and long (6 months)term survival and functional outcome.Age did not correlate to short term, but to long term survival and GOS.Multivariate regression analysis provedage, GCS, hydrocephalus and hemor-rhage as independent variables to predict functional outcome whereasmidline shift and LeRoux-score did not.Prediction accuracy for good (GOS 4-5) or poor (GOS 1-3) outcome was0.94 in this model. Conclusion: Prognosis of intracerebralhemorrhage with associated intraven-trikular hemorrhage treated with ventricular drainage can be predictedwith high accuracy in multivariateregression analysis. Age above 60 yearsis clearly associated with unfavorableoutcome. The prognostic factors will be evaluated in a prospective protocol.

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184. Clinical Validation of a new AutomatedSoftware for 3D MRA Analysis in PatientsUndergoing Carotid EndarterectomyRaphael Guzman, MD (Stanford, CA)

Introduction: Success of carotidendarterectomy (CEA) is not only determined by the perioperative occurrence of neurological complications,but also depends on the quality of vessel reconstruction. Magnetic resonanceangiography (3D-MRA) offers a non-i n v a s i v emethod for systematic post-surgical controls. However a user independent andaccurate post-processing tool for objectiveanalysis would be needed. The purpose ofthis study was to validate a new semiautomated software for 3D-MRA quantification. Method: (1) In 10 patients 3D-MRA andDSA based diameter measurements of 20common carotid (CCA) and internal carotidarteries (ICA) were performed. (2) In 12patients the diameters of 24 CCA weremeasured by means of 3D-MRA and US.(3) In 30 patients undergoing CEA, CCAand ICA diameters were measured intraop-eratively and compared with 3D-MRAmeasurements. Results: In series (1) and (2), the meandiameters (plus or minus SEM) of the CCAwere 8.0 plus or minus 0.2, 7.8 plus orminus 0.3mm and 8.3 plus or minus 0.3as measured on 3D-MRA, DSA and USrespectively. The mean diameters of theICA (plus or minus SEM) were 5.4 plus orminus 0.1 and 5.4 plus or minus 0.2 for3D-MRA and DSA respectively. For series(3) the mean diameters (plus or minusSEM) for the CCA were 9.7 plus or minus0.2 and 9.8 plus or minus 0.2 and for theICA 6.6 plus or minus 0.2 and 6 plus orminus 0.2 as measured on 3D-MRA and during CEA respectively. Overall a statistically significant correlation betweenthe 4 measurement methods was found. Conclusions: This new automated software for 3D-MRA segmentation and quantification allows accurate measurements of carotid artery dimen-sions. Systematic application of suchmeasurements could improve the qualitycontrol of CEA.

185. Coiling of Middle Cerebral ArteryRuptured and Unruptured Aneurysms. Is There an Indication?Hunaldo J. Villalobos, MD; Ricardo Hanel, MD;Christopher R. Magnano; Elad I. Levy, MD; LeeR. Guterman, MD, PhD; L. Hopkins, MD (Buffalo, NY)

Introduction: Middle cerebral artery(MCA) aneurysms are considered unfavor-able for endovascular treatment as the M2branches often originate from theaneurysm neck. Methods: To determine the results following endovascular treatment of MCAaneurysms, a retrospective review involv-ing patients with MCA aneurysms treatedby coiling at our center between 1998 and2004. The degree of aneurysm occlusionwas evaluated in addition to the followinganeurysm characteristics: ruptured versusunruptured, dome-to-neck ratio, size, andlocation.Results: The study population consistedof 14 patients (9 women; mean age 52.6years, range 25-84 years) with 10 (71 percent) unruptured and 4 (28 percent)ruptured lesions. Aneurysm locations wereas follows: 10 (71 percent) M1-bifurcation,2 (14 percent) M1-trunk, 1 each (7 percenteach) distal-M2 and distal-M3. The meandiameter was 9.7mm (range 5.6-15mm).Dome-to-neck ratio was grouped as follows: less-than two, 5 patients (35.7percent); between two and three, 7patients (50 percent); greater-than three, 2patients (14.3 percent). Immediate results:complete-occlusion, 4 patients (28.5 per-cent); incomplete-occlusion (90 percent ormore), 5 patients (35.7 percent); incom-plete-occlusion (less-than 90 percent), 4 patients (28.5 percent). There was one technical-failure, and one-case of re-rupture occurred after intentional partial coiling. Ten-patients had follow-upangiograms (avg. follow-up time 10.4months), and one-patient had a recurrencethat was coiled.Conclusions: MCA-aneurysms with favor-able anatomy are amenable for coiling forselect cases. The risk of re-bleeding afterpartial coiling of ruptured aneurysmsexists and should be considered whenselecting the treatment.

186. Endosaccular Obliteration of Wide-Necked Intracranial AneurysmsUsing a Self-Expandable Stent and Self-Expandable Hydrophilic CoilCombinationYasunari Niimi, MD; Jonathan L. Brisman, MD;Joon K. Song, MD; Alejandro Berenstein, MD(New York, NY)

Introduction: The endovascular treatmentof wide-necked intracranial aneurysms isevolving. We report a treatment optioncombining newly available devices to dealwith such challenging lesions. Methods: A new self expanding stent, theNeuroform (Boston Scientific, Natick, MA),is now available. It is a flexible device thatis small enough (3 French) to be safelydeployed within the intracranial vascula-ture. Concomitantly, a new generation ofcoils that incorporate a self expandablehydrophilic lining (HydroCoil, MicroVe n t i o n ,Inc., Aliso Viejo, CA) is now availabledesigned to result in better endosaccularfilling of the aneurysm. The combination ofNeuroform stents and HydroCoils to tightlyocclude brain aneurysms has not beendescribed before.Results: We report seven cases in which the Neuroform stent was used toassist with endosaccular obliteration ofintracranial aneurysms using expandableHydroCoils. Successful aneurysm occlu-sion was achieved in all patients. Stentswere placed as a planned procedure in sixpatients; in one patient, emergent stentplacement was employed to protect theparent vessel from a herniating coil mass.There were two stent malplacements and two thromboembolic phenomenon, with no long-term clinical sequelae. Angiographicfollow-up was available in three patients,two at one year post-procedure. In onepatient there was mild coil compaction and aneurysm recanalization.Conclusions: We document the first clinical use of a combined new intracra-nially navigable stent and expandable coils in the successful treatment of wide-necked brain aneurysms. Stent-assisted endosaccular treatment ofintracranial aneurysms with this new generation of coils may prove superior to other techniques for treating such difficult aneurysms

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P OSTER PRESENTATION ABSTRACTS187. The Evolution of Endovascular

Technology for Treating TraumaticCraniocervical Artery DissectionScott Williams, MD, PhD; Lilia Hardin;Meng C. Vang, MD (Memphis, TN)

Introduction: Carotid and vertebralartery dissections and pseudoa-neurysms are common complicationsof blunt trauma. Patients who aresymptomatic or who fail medical treatment have been treated using avariety of endovascular techniques. We present a retrospective review ofour technical and clinical experience inthe endovascular treatment of cranio-cervical arterial dissection andpseudoaneurysm. Methods: Retrospective case series ofcraniocervical dissections treated withendovascular techniquesResults: From 1995 to 2004 we treated82 cases of traumatic craniocervicalartery dissection that were treated froman endovascular approach.Conclusions: Techniques used in thisseries characterize the progression of mechanical revascularization andembolization technology. Clinical andlong-term angiographic follow-updemonstrate favorable clinical out-comes as endovascular treatmentoptions have rapidly evolved.

188. Confirmation of Venous DrainageReduction in Vein of Galen AVMFollowing Endovascular EmbolizationUsing Non-invasive Optimal VesselAnalysis Computer ProgramMark Chwajol, MD (Bronx, NY); Joon Song,MD; Yasunari Niimi, MD; AlejandroBerenstein, MD; David Langer, MD (New York, NY)

Introduction: Recent advances in MRA and MRV engineering such asnon-invasive optimal vessel analysis(NOVA) computer program haveallowed for the development of non-invasive measurements of arterial and venous cerebral blood flow.Measurement of AVM venous flowusing MRA has not been reported in literature. Hemodynamic patterns invein of Galen arteriovenous malforma-tions (AVM) have not been adequatelystudied. We hypothesized the NOVAcould provide reliable quantifiablemeasurement of cerebral venous bloodflow, confirm an abnormal venous outflow, and demonstrate reduction ofhigh flow after AVM embolization procedure.

Methods: Three children with a knownvein of Galen AVM were admitted fortreatment. MRI-NOVA studies wereobtained before and after endovascularintervention. Flows were measured inthe straight, sagittal, and both trans-verse sinuses using NOVA.Results: Using NOVA we were able to measure venous blood flow in major sinuses of the brain. A three-dimensional representation of venousflow with direction can be generatedusing NOVA 4-D analysis. Comparisonsof pre-and post-embolization flowsdocumented successful endovasculartreatment of vein of Galen AVMs.Conclusions: Venous flow and direc-tion in draining sinuses of the braincan be measured using NOVA tech-nique. We were able to quantify flowreduction and changes in venousdrainage patterns following endovascu-lar embolization of AVM. Informationobtained from NOVA studies can serveas an invaluable adjunct in diagnosis,treatment, and follow-up of patientswith AVMs and adds to our under-standing of cerebrovascular disease ingeneral.

189. Snare Assisted Catheterization of theCavernous Sinus for Embolization ofCarotid Cavernous FistulasJohn P. Deveikis, MD (Charleston, SC)

Introduction: Endovascular treatmentis the treatment of choice for directcarotid cavernous fistulae. Some fistulae may not be suitable for balloonembolization and detachable balloonsare no longer readily available in theUnited States. Thus, coil embolizationhas become the mainstay of treatment.The cavernous sinus is catheterizedeither by a trans-arterial route via thefistula, or a trans-venous route, andcoils placed to occlude the fistula. Asharply angulated fistula may impairtrans-arterial access and venous stenosis or occlusion may impairtransvenous access. A stent-assistedcatheterization technique that can facili-tate catheterization and embolization inthese difficult cases is reported here. Methods: Of 10 patients with directcarotid cavernous fistulae treatedexclusively by coil embolization overthe last 4 years, two had had character-istics of the fistula itself and the draining veins that greatly impairedcatheterization of the target cavernoussinus. When angulation of the vessel orstenosis or irregularity of the venouspathway would preclude catheterization

of the vessel with standard techniques,snare-assisted catheterization was per-formed. The details of the techniquewill be described.Results: In both cases, the desiredcatheter position was achieved usingthe snare-assisted technique. The fistula was successfully treated withoutcomplications.Conclusions: When catheterization of the cavernous sinus is difficult,snare assisted catheterization may be helpful to gain access to the sinusand allow for coil embolization ofcarotid-cavernous fistulae.

190. Ophthalmic Artery Flow DuringCarotid Artery StentingShoichiro Kawaguchi, MD; Kenta Fujmoto,MD; Jun-ichi Iida, MD; Hideaki Mishima,MD; Kaoru Horiuchi, MD; Toshisuke Sakaki,MD (Kashihara, Japan)

Introduction: The authors examinedthe flow pattern and the high intensitytransit signals (HITS) of the ophthalmicartery during carotid artery stenting(CAS). To complete the above purpose,the authors examined the ophthalmica r t e ry using color Doppler flow imaging(CDFI) during CAS. Methods: We examined 16 patientswith carotid artery stenosis (more than 70% stenosis) at its origin treatedwith CAS. Duplex Sonography of eachtreated carotid artery showed theunstable plaque on 10 patients and theulcer on 9 patients. Ophthalmic arteryCDFI indicated ophthalmic artery flowdirection, peak systolic flow velocityand HITS during CAS procedure.Results: 1) Before CAS, ophthalmicartery flow directions were antegradeflow in 6 patients, reversed flow in 9patients, and to and fro pattern in 1patient. During CAS, the flow directionof the ophthalmic artery changeddepending on each CAS procedure.Reversed ophthalmic artery flow wasseen on 12 patients at the predilatationprocedure and 15 patients at the post-dilatation procedure. Immediately afterCAS, the ophthalmic artery flow direc-tion was normal in all cases. 2) HITSon ophthalmic artery was seen on 13patients (81%), and it was seen signifi-cantly (p less than 0.05) frequent inthe patients with unstable plaque orulcer formation especially during thewiring, predilatation and postdilatationtechnique compared to the patientswithout unstable plaque or ulcerformation.

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Conclusions: Cerebral or retinal embolismthrough the ophthalmic artery could bedeveloped during CAS procedure. Toprevent the above, the precise analysis ofthe plaque and careful CAS techniqueshould be needed.

191. Effect of Cigarette Smoke on BrainElastase ActivityIan B. Ross, MD; Gregory A. Ordway, PhD;Soundar Regunathan, PhD; Sharonda Swilley,BS; Katalin Szebeni, MD; Eugene V. Golanov,MD, PhD (Jackson, MS)

Introduction: The cause of cerebralaneurysm formation appears to be multi-factorial and has not been fully elucidated.Inhalation of tobacco smoke has beenlinked to aneurysm formation and sub-arachnoid hemorrhage. Elastases, alsoknow as matrix metalloproteinases(MMPs), have been demonstrated to beimportant in vascular remodeling and havebeen implicated in the genesis of cerebralaneurysms. This study was designed todetermine if smoking increases elastaseactivity in the brain. Methods: Male Sprague Dawley rats wereexposed to either cigarette smoke (n=8) orair (n=8) through a nose only inhalationexposure system (CH Technologies USA,Inc) in four 35 minute sessions of expo-sure per day for a total of 28 days. Aftersacrifice, the brains were frozen. Afterhomogenization, brain elastase activitywas tested by evaluating the gelatinaseactivity (EnzCheck Gelatinase kit, MolecularProbes). Changes in MMP9 protein levelswere determined by Western blot.Results: Enzyme activity was notincreased in the rats that had been exposedto smoke compared to non-smoke con-trols. Indeed, there was a trend todecreased activity in the smoked rats.Western blot failed to demonstratechanges in MMP9 levels between ratsexposed to smoke and the controls.Conclusions: Neither MMP9 activity norlevels of MMP9 appear to be modified by cigarette smoking. Further study is required to examine the isolated effect of tobacco smoke on the cerebral vasculature, not only in terms of enzymaticactivity but also on levels of a variety ofMMPs and perhaps on their correspondingtissue inhibitors (TIMPs).

192. Correlation Between Cerebral Blood Flow Measured by MRI-NOVA ComputerProgram and Transcranial DopplerUltrasonogrphy Measurements of BloodVelocity in Evaluating CerebralVasospasm After SubarachnoidHemorrhageMark Chwajol, MD (Bronx, NY); David Langer,MD (New York, NY)

Introduction: Non-invasive, precise quantification of cerebral blood flow as avaluable means in evaluating patients forsuspected cerebral vasospasm after sub-arachnoid hemorrhage has been underinvestigation. Transcranial Doppler (TCD)ultrasonography has been used to detectelevated blood velocities suggesting cere-bral vasospasm. The usefulness of TCDrecording in clinical decision-making hasbeen questioned mainly due to its inabilityto directly measure blood flow or vesseldiameter. MRI-based non-invasive optimalvessel analysis (NOVA) computer programallows for non-invasive measurements ofarterial cerebral blood flow (CBF). Weinvestigated whether there is a correlationbetween NOVA direct measurements ofCBF and TCD recordings. Methods: Four patients with grade I - IIIsubarachnoid hemorrhage who underwentcraniotomy for aneurysm clipping werestudied. TCD recordings were performedwithin 12 hours of MRI-NOVA study. Thedegree of correlation between NOVA CBFand flow velocity measurements was ana-lyzed.Results: We were able to illustrate therelationship between CBF measurementsusing MRI-NOVA and flow velocities meas-urements using TCD recordings. Lowervelocities correspond to higher cerebralflow and with increasing velocities by TCDCBF decreases on MRI-NOVA.Conclusions: CBF can accurately bemeasured using MRI-NOVA. Using NOVA,we have demonstrated that there is a cor-relation between CBF and blood velocitiesidentified on TCD recordings. TCD ultra-sonography is a valuable technique andcan safely be used in evaluating the pres-ence or degree of cerebral vasospasm.MRI-NOVA is an equally valuable modalityand might be used in problematic cases oras an invaluable adjunct in both diagnosisand serial follow-ups in patients with suspected vasospasm.

193. Feasibility Study of Vertebral Origin StentPlacement with Distal ProtectionAdnan I. Qureshi, MD; Jawad F. Kirmani, MD;Pansy Harris-Lane, NP; Afshin A. Divani, PhD;Nazli Janjua, MD; Ammar AlKawi, MD (Newark, NJ)

Introduction: To report the feasibility,safety, and 1-month results of performingstent placement for vertebral origin steno-sis using a distal protection device. Distalprotection devices have been shown toreduce the number of cerebral emboli andsubsequent ischemic events when used as adjuncts to percutaneous carotid intervention. Methods: We determined rates of techni-cal success, defined as deployment of distal protection device and stent at targetlesion followed by retrieval of the device,and 1-month major stroke or death associated with stent placement using distal protection (Filter EX, BostonScientific, Freemont, CA) in patients withsymptomatic vertebral artery origin stenosis.Major stroke was defined as a new strokewith National Institute of Health StrokeScale score greater than or equal to 4.Further outcomes included any stroke,transient ischemic attack, and majoradverse events.Results: Technical success was achievedin 7 of the 8 patients in whom distal pro-tection device placement was attempted.The mean age of the 7 patients was 69years (52 to 88 years) and included 4 menand 6 women. Either Femoral (5) or radial(2) approach was used. The device wassuccessfully deployed and retrieved in allcases using a 4F catheter. Stent placementwas successful in all 7 procedures. Onedevice held macroscopically visible debris.No major stroke or death was observed at1-month follow-up.Conclusions: The present study demon-strates feasibility of performing stentplacement for vertebral artery origin stenosis using distal protection devices.Further studies to determine the effective-ness of drug eluting stents for intracranialstenosis are required.

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P OSTER PRESENTATION ABSTRACTS194. Prognostic Significance of

Subcategories of Proximal MiddleCerebral Artery (M1) OcclusionsDetermined by the Qureshi GradingSchemeYousef M. Mohammad, MD, MSc; GregoryA. Christoforidis, MD; Eric C. Bourekas,MD; Andrew P. Slivka, MD (Columbus, OH)

Introduction: We tested the hypothesisthat variation in the collateral circula-tion and lenticulostriate artery involve-ment affects the outcome followingthrombolysis in patients with middlecerebral artery (MCA) occlusion. Methods: The occlusions in patientswith proximal MCA (M1 segment)occlusion treated with intra-arterialtherapy within 6 hours were subclassi-fied using the Qureshi grading schemeby a neuroradiologist blinded to theclinical examination. The grading wasas follows: Grade 3A; sparing of thelenticulostriate branches and/or visuali-zation of leptomeningeal collateralsgreater than 1/3 of the MCA territory,or Grade 3B; no visualized flow to thelenticulostriate branches; and absentleptomeningeal collaterals to the MCAterritory. The differences in the rates of modified Rankin scale (MRS) at discharge and infarct volume at 24 to48 hours on computed tomographicscan were analyzed. Results: A total of 32 patients withocclusion of the M1 segment of theMCA were categorized as grade 3A(n=25) and 3B (n=7). The volume of infarction (mean plus or minus standard deviation) was significantlygreater for grade 3B compared withgrade 3A (198 plus or minus 35 cc versus 49 plus or minus 17 cc, p less than 0.05). A significant difference was observed in volume of infarctionaccording to subcategories of M1 segment occlusion (F ratio 15.2,p=0.007) after adjusting for age, timeto treatment, and initial NIHSS score. Conclusion: The present study empha-sizes the importance of leptomeningealcollaterals and involvement of lenticu-lostriate arteries as determined by theQureshi grading scheme in determina-tion of final ischemic injury in patientswith proximal MCA occlusion.

195. “String” Polymer Implantation in aHuman Cadaver Head UsingStereotactic Techniques: TechnicalReportQuoc-Anh Thai, MD; Gustavo Pradilla, MD;Federico Legnani, MD; Wesley Hsu, MD;Henry Brem, MD, FACS; Rafael J. Tamargo,MD, FACS (Baltimore, MD)

Introduction: Locally implanted controlled-release polymers are suitedfor the treatment of intraparenchymalhemorrhages and are not associatedwith risks inherent with systemic treat-ments. Stereotactic implantation ofcontrolled-release polymers that can be inserted through a cannula wouldobviate the need for a craniotomy, limitanesthetic exposure, and reduce proce-dural costs. We describe a techniquefor making controlled-release “string”polymers that can be stereotacticallyimplanted using the Cosman-Robert-Wells (CRW) system. Methods: We modified our previouslydescribed technique for preparing controlled-release ethylene-vinylacetate (EVAc) polymers by using an18-Gauge needle as the mold for thepolymer, yielding 20-Gauge “string”-shaped polymers. “String” polymerscontaining Evans blue dye (EBD) orbarium sulfate (EVAc polymer, 40%vinyl acetate by weight and barium sul-fate or EBD) were made by dissolvingthe components in methylene chloridein a 6:4 ratio. Then, using a cadaverhead, a CRW frame was attached, anda head CT was performed for localiza-tion. “String” polymers were implantedusing standard needle-guided stereo-tactic techniques. Results: Stereotactic implantation ofthe barium sulfate polymer was con-firmed on CT scan. Three-dimensionalreconstruction of the CT image showedthe polymers at the intended target.Polymers loaded with EBD implantedstereotactically showed expectedrelease from the polymers into theinterstitial tissue over one week. Conclusion: Surgically implantable controlled-release “string” polymersare effective vehicles to deliver thera-peutic agents locally at the site ofpathology. Patients with intraparenchy-mal hemorrhages that do not requireopen craniotomy may benefit fromthrombolytics delivered via controlled-release “string” polymers without systemic risks.

196. Brachytherapy for Recurrent CarotidStenosisEdwin J. Cunningham, MD; Peter A.Rasmussen, MD; Thomas J. Masaryk, MD(Cleveland, OH)

Introduction: Carotid restenosis within36 months of carotid endarterectomy is generally attributed to myointimalhyperplasia. Because of the higher ofrisk of neurologic and wound compli-cations associated with re-operation forrestenosis, many centers favor carotidangioplasty-stenting (CAS) in this setting. A subset of patients undergo-ing CAS will develop early symptomaticor asymptomatic carotid restenosisrequiring further treatment. Based on favorable results achieved in thecoronary artery circulation, we hypoth-esized that angioplasty-brachytherapyis an effective treatment for myointimalhyperplastic restenosis of the carotidartery. We present three cases in whichbrachytherapy was combined withangioplasty for the treatment of earlyrestenosis after CAS. Cases andIntervention: Three patients who devel-oped restenosis within 18 months ofcarotid endarterectomy were referredfor CAS. All three patients underwentuncomplicated CAS but developedsevere ultrasonographic restenosis (1patient symptomatic, 2 patients asymp-tomatic) within 12 months of CAS.Carotid angioplasty and intra-arterialbrachytherapy with Iridium-192 using acommercially available delivery systemwere subsequently performed. At 2-year follow-up from the angioplasty-brachytherapy, all three patients remainclinically stable and demonstrate noprogression of stenosis on duplex U/S. Conclusions: Carotid angioplasty-brachytherapy may be an effectivemethod of managing early restenosisafter carotid angioplasty-stenting.

197. Long-Term Evaluation of ALGEL forEmbolization of Cerebral AneurysmsTim A. Becker, PhD (Ann Arbor, MI);Cameron G. McDougall, MD, FRCSC; MarkC. Preul, MD; William D. Bichard (Phoenix,AZ); Daryl R. Kipke, PhD (Ann Arbor, MI)

Introduction: We assessed the stabilityand bioactivity of calcium alginate(ALGEL) in swine aneurysm models.ALGEL is a biocompatible hydrogel that has been optimized for controlleddelivery through microcatheters andlong-term stability in vascular defects.ALGEL is slated to begin clinical

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assessment for pre-surgical treatment ofAVMs, and has shown promise in pre-clin-ical assessment for aneurysm treatment.Methods: Lateral wall common carotidartery aneurysm models were constructedfrom jugular vein pouches in six swine.The aneurysm models were embolizedwith ALGEL delivered from a concentric-tube microcatheter. A balloon was inflatedacross the aneurysm neck and micro-catheter to provide parent vessel protec-tion during injection. Three animals weresurvived for one-month, two for two-months, and one for three-months. Results: The survival aneurysm modelocclusions resulted in 90-100% occlusionof the aneurysm sac with minimal t h r o m-bus formation in the fundus. All six animalsrecovered without signs of neurologicaldeterioration during their survival periods.Pre-termination angiograms showed thatall aneurysm models remained occludedand that the parent vessel remained open.Histology showed the treated aneurysmswere completely filled with ALGEL, whichprovided a template for tissue growthacross the aneurysm neck. Conclusion: Controlled delivery of ALGELcan consistently attain at least 90% fill ofan aneurysm, thus repairing the vessel andobviating the aneurysm from circulatoryforces. The result is a mechanically stableocclusion that resists aneurysm recurrenceand promotes aneurysm neck repair. Thisnew generation of hydrogels show signifi-cant benefits over metal coils or other cur-rent non-biocompatible materials forembolizing aneurysms.

198. Endovascular Tumor Induction andAdenoviral Vector Delivery in a RabbitModelTetsu Satow, MD, PhD; Harold D. Shine, PhD;Charles M. Strother, MD; Micheal Barry, PhD;Goetz Benndorf, MD, PhD; Sergin Akpek, MD;Michel E. Mawad, MD (Houston, TX)

Introduction: Malignant brain tumorsremain as a therapeutic challenge. Use ofgene therapy for these tumors is ham-pered by the inability to obtain completedistribution of therapeutic vector withoutunacceptable systemic effects. To developa catheter based technique for delivery ofadenoviral vectors to select organs toincrease tissue-specific gene delivery whilereducing delivery to non-target tissue, wehave established a rabbit model suitablefor both induction of tumor and delivery ofa vector through endovascular techniques. Methods: 10 New Zealand White Rabbitswere used. Following anesthesia with ketamine and Isoflurane, one femoral

artery was cannulated with 4F catheter.Using a 3-F microcatheter, a suspension of rabbit VX2 carcinoma was injected intoa branch of a renal artery. Ten days later,an adenoviral vector (1 x 1011 particles)containing the gene for LacZ was injectedinto the same artery during flow arrest.The kidneys were harvested seven daysafter vector injection.Results: Standard histological and histo-chemical analyses were used to documentthe formation of tumors in the kidney andtransduction of tissue at the site of vectorinfusion. Histological examination revealedlive VX2 tumor cells only in the injectedkidney. X-gal histochemistry revealed thattissues in the vicinity of the vector infusionwere positive for beta-galactosidase activi-ty indicating that the vector transducedthese tissues.Conclusions: This model provides ameans to test techniques for the therapeu-tic delivery of adenoviral vectors into a targeted tissue while restricting gene delivery to non-targeted tissue.

199. Endovascular Management of Dizziness,Vertigo, and Syncope Resulting FromPosterior Circulation IschemiaRobert A. Koenigsberg, DO; Nakul Vakil, MSc(Philadelphia, PA)

Introduction: To evaluate vertebral arterystent-supported angioplasty in the man-agement of dizziness, vertigo, and syncoperesulting from posterior circulationischemia. Methods: We reviewed 20 consecutivecases of extra-cranial vertebral arterystent-supported angioplasty based on: presenting symptoms, past medical history, procedural success, and length ofstay (LOS).Results: All procedures were performedsuccessfully without complication. Onepatient (5%) experienced stent failure at 3 months follow-up. Mean LOS was 2.67days. Symptoms at presentation included:dizziness (40%), difficulty ambulating(40%), weakness (25%), speech (15%) or visual deficit (30%), syncope (5%), and vertigo (5%). All patients with the primary complaints of dizziness, vertigo, and syncope (45% of overall patients)showed significant or complete resolution of symptoms.Conclusions: Vertebral artery stent-supported angioplasty may offer a viabletherapy for dizziness, syncope, and vertigo resulting from posterior circulationischemia.

200. Orientation of an Aneurysm Clip Alongthe Neck Affects Shear Stress and FlowVelocities Within a Residual Aneurysmand its Parent VesselDawn A. Lott, PhD; Hans Chaudhry, PhD;Michael Siegel, PhD; Charles J. Prestigiacomo,MD (Newark, NJ)

Introduction: Computer simulation of flowwithin an aneurysm has helped delineateevents that may contribute to furtheraneurysm growth and rupture. Worksdescribing changes in flow dynamics within residual aneurysms are few. Wedeveloped a side-wall saccular aneurysmmodel, then created and compared variably- shaped residual aneurysms withpartial obliteration of the inflow or outflowzones, by simulating aneurysm clip placement. Methods: A finite-volume based packagefor modeling complex fluid flow was utilized in developing the aneury s m model.A 5.3 mm aneurysm with a 3.1mm neckwas analyzed under pulsed-flow conditionsafter a minimum of five cycles. From thisbase model, residual aneurysms were created by simulating clip placement at different angles relative to theaneurysms inflow and outflow zones andthe model subjected to identical condi-tions. Shear stresses and velocities withinthe parent vessel, aneurysm, and interfacewere determined and compared. Results: When compared to the untreatedaneurysm, partial obliteration of the neckin any configuration increased shear stressalong the distal neck (inflow zone) andedge of the clip. The residual aneurysmwith the clip angled toward the outflowzone exhibited significantly higher shearstress, when compared to the model withthe clip angled toward the inflow zone(greater than 2.0 Pascal vs. 0.8-1.0 Pascal,respectively). Elevations in velocities anddynamic pressures paralleled these findings. Conclusion: The angle of clip placementrelative to inflow/outflow zones significant-ly alters the flow dynamics within theaneurysm and its parent vessel. Furtherstudies may help explain why certain residual aneurysms grow whereas othersremain unchanged or spontaneouslyresolve.

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P OSTER PRESENTATION ABSTRACTS201. Comparison of Computer Simulation

of Biofluidmechanical ExperimentsWith Experiments on Silicon Modelsof Human Cerebral AneurysmsAndreas Spuler, MD; Leonid Goubergrits,PhD; Christoph Petz, BSC; Detlev Stalling,BSC; Juergen Kiwit, MD, PhD; Klaus Affeld,PhD (Berlin, Germany)

Introduction: Blood dynamics and biofluidmechanical properties of humananeurysms are elusive to observationin vivo. Biofluidmechanical parameterscan be described by means of computersimulation. The aim of our study is thecomparison of biofluidmechanicalexperiments using silicon models ofreal human aneurysms with the corre-sponding numeric simulations. Methods: Raw data of human cerebralaneurysms were created by means of conventional CT-angiography. Three-dimensional geometrical models of theaneurysms with inflow and outflowbranches were derived. These modelswere transformed to three-dimensionalgrids, which we used to performnumeric calculations of the biofluidme-chanical parameters. From the samethree-dimensional data, threefold upscaled transparent silicon models ofthe aneurysms were fabricated. Steadyaneurysmal flow was visualized by thedye washout method. Results: The numeric experiments ofsteady aneurysmal flow correspondvery well with dye washout experi-ments performed on the correspondingsilicon models. Conclusion: Numeric simulations canpartly replace biofluidmechanicalexperiments on silicon models ofhuman cerebral aneurysms. Our studyconfirmed the validity of numeric sim-ulations of biofluidmechanical parame-ters of cerebral aneurysms.

202. The Usefulness of ComputedTomography Angiography for theDiagnosis and PostoperativeEvaluation of Cerebral AneurysmsTaegoo Cho, MD (Puchon-Shi, Kyunggido,Republic of Korea)

Introduction: With the development of computed tomography angiography(CTA) techniques most of the cerebralaneurysms can be diagnosed and alsoevaluated after surgery using CTA. CTA only method could be used for thediagnosis and postoperative evaluationof cerebral aneurysms.

Methods: During the last 4 years fromMarch 2000 to July 2004, we operated37 cases of cerebral aneurysms basedon CTA only for the diagnosis andpostoperative follow-up. We set up anemergency CTA for the evaluation ofsubarachnoid hemorrhages at ER. Weperformed the CTA as soon as possiblefor the evaluation of subarachnoidhemorrhages or intraventricular hemorrhages. When the aneurysm was detected we operated the patient,and also performed the CTA for thepostoperative evaluation.Results: There were 37 patients with38 cerebral aneurysms. Anterior com-municating artery aneurysm was mostcommon with 15 cases, and 13 casesof internal carotid artery aneurysm and9 cases of middle cerebral arteryaneurysm and 1 case of basilar arteryaneurysm. CTA was done again on the1st postoperative day after craniotomyfor follow-up. We could accuratelyidentify the neck areas of the cerebralaneurysms where one or two titaniumclips were used. If one or two titaniumclips are used to clip cerebralaneurysms, CTA was satisfactorymethod to identify the results whetherthe parent and branching arteries areoccluded.Conclusions: CTA only method can beused as a reliable alternative method toconventional angiography in the diag-nosis of cerebral aneurysms and forthe postoperative evaluation.

203. Prospective Validation of a Model forNeurological Outcome FollowingSurgery of Brain ArteriovenousMalformations: Preliminary ResultsJulian Spears, MD, FRCS(C); KarelTerBrugge, MD, FRCSC; M.C. Wallace, MD,FRCS(C); Michael Tymianski, MD, FRCS(C)(Toronto, ON Canada);

Introduction: The authors previously proposed a modification to the originalSpetzler Martin AVM grading scale inan attempt to make the scale more dis-criminative. The grading scale was gen-erated based on odds ratios for eachsignificant variable ( Eloquence = 4pts,Diffuse Nidus = 3pts, Deep VenousDrainage = 2pts; Low Risk = 0-2pts,Moderate Risk = 3-5pts, High Risk = 6-8pts and Very High Risk = greater than8pts). Preliminary validation of themodel is presented. Methods: Twenty-six consecutivelysurgically treated patients harboring abrain AVM over a two year period were

studied in an attempt to prospectivelyvalidate the original model. New neuro-logical deficits (NND), early disablingneurological outcomes (= 1 week) andlate disabling outcomes (at or beyond1 year) following surgery were recorded. Results: In the validation phase of thestudy the mortality rate was 0%. Nopatients in the low risk category (n=8)experienced a NND or poor early out-come. In the moderate risk group(n=10), 70% experienced a NND, noneof which were disabling at early or latefollow-up. In the high risk group (n=6)83% experienced a NND of which 33%were disabling at early follow-up. In the very high risk group (n=2) 100%experienced a NND and an early pooroutcome. Late disabling outcomes areyet to be determined in both the highand very high risk groups. Conclusion: Preliminary application ofthis simple model appears to demon-strate reliable discrimination betweengrades of brain AVMs with respect tothe surgical risk associated with theirextirpation.

204. Percutaneous Intraspinal Navigation(PIN)-Based Fiberscopic andVideoscopic Endoscopy of theLumbosacral Thecal SacBrian Giles, MD (Dallas, TX); TakuyaFujimoto, MD (Kobe, Japan); Robert E.Replogle, MD; Susan H. Miller, RT; PhillipD. Purdy, MD (Dallas, TX)

Introduction: Numerous conditions,including spasticity and incontinence,are related to spinal cord and lum-bosacral nerve root pathology. In aneffort to reduce the morbidity of opensurgical approaches, less invasive techniques are being sought. A percu-taneous technique for visualizing andmanipulating lumbosacral nerve rootswith endoscopy is described using a combination of endoscopy and X-ray fluoroscopy, and image quality of fiberscopic versus videoscopicendoscopy is compared. Methods: Two unembalmed malecadavers were brought to our researchangiography suite and placed in theprone position. A 7.5-French (F)fiberoptic endoscope was introducedinto the subarachnoid space at the L1-L2 level through a 9F sheath andadvanced caudally into the lumbarcanal under both X-ray fluoroscopy andendoscopic visualization. In the secondcadaver a 5mm videoscope using aCCD chip for image acquisition was

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introduced into the subarachnoid space via a partial laminectomy and was alsoadvanced caudally into the lumbar canalunder both fluoroscopy and direct endoscopic visualization. Results: Real-time endoscopic and X-rayfluoroscopic images of the lumbosacralnerve roots, arachnoid, vessels, and thefilum terminale were obtained with both afiberoptic endoscope and a videoscope.Nerve roots were manipulated withgraspers introduced through the workingchannel of the videoscope. Conclusion: Accessing the lumbosacralthecal sac via the PIN technique is feasiblein cadaver models and offers a potentialalternative to open surgical exposure.Image resolution is greatly enhanced withvideoscopic endoscopy as compared tofiberscopic endoscopy. Further study isneeded to determine the safety and efficacy of this technique in live subjects.

205. Angio-Seal Hemostatic Aarterial ClosureDevice in Neuro-AngiographicProcedures: Preliminary Experience From CornellVallabh Janardhan, MD; David Wells-Roth, MD;Philip E. Stieg, PhD, MD; Y Gobin, MD; HowardRiina, MD (New York, NY)

Introduction: The Angio-Seal hemostaticarterial closure device achieves hemostasisby sandwiching the arteriotomy between abioabsorbable polymer anchor and a colla-gen sponge. Safety and efficacy of thisdevice has been studied after cardiaccatheterizations but only case reports exist about its use in neuro-angiography.Methods: We prospectively evaluated thesafety of the Angio-Seal device in a con-secutive series of patients who underwentneuro-angiographic procedures (neuro-interventional=30;diagnostic=35). Patientsrequiring 5 French sheaths or larger hadarterial closure devices for hemostasis.Manual compression (average of 20 minutes) was performed in children, inpatients requiring smaller sheaths (3/4French), or those with infection. Patients inwhom the Perclose device was used, wereexcluded (n=2). Clinical outcomes wereassessed at time of discharge or after 24 hours. Results: 65 patients were studied andhemostasis was achieved by manual compression (n=23) or an Angio-Sealdevice (femoral n=41; carotid n=1). Four French sheath was used in 15patients (Angio-Seal=0), a 5/6 Frenchsheath was used in 40 patients (Angio-Seal=33), and a 7 French or larger sheathwas used in 10 patients (Angio-Seal=9).There were no groin hematomas in the

Angio-Seal group and one groin hematomarelated to manual compression. Therewere no other complications. Mean recoveryroom time due to bed rest restrictions inthe manual compression group was 4.4hours (range:4-6 hours) compared to 1-hour for the Angio-Seal group. Conclusion: The use of Angio-Seal arterialclosure devices after neuro-angiographicprocedures to achieve hemostasis seemsto be safe, feasible, and achieves earlierpatient ambulation compared to manualcompression. Larger prospective studiesneed to further evaluate the long-termsafety and efficacy of this device.

206. Intra-orbital Arteriovenous Fistulae of theOphthalmic VeinsLouis P. Caragine, Jr. (Danville, PA); VanHalbach, MD; Chris Dowd, MD; RandallHigashida, MD (San Francisco, CA)

Introduction: Intra-orbital dural arteriove-nous fistulas (AFV) of the ophthalmic veinhave not previously been described in theliterature. This article describes a series ofthree such cases and discusses treatmentwith transvenous occlusion. Methods and Results: Two women, 51and 63 years old, presented with proptosisand chemosis mimicking a carotid-cavernous fistula. In both cases, cerebralangiography revealed an intra-orbital duralarteriovenous fistula of the superior andinferior ophthalmic vein respectively. Bothpatients underwent transvenous ablation ofthe dural AVF retrograde via the facial veinand subsequently had complete resolutionof the presenting symptoms (Figs. 1-6).The third patient, a 13-year-old girl, has ahistory of multiple acquired intracranial fistulae. A left intra-orbital fistula devel-oped since 1990, far removed from thecavernous sinus. A smaller inferior ophthalmic fistula was occluded via atransvenous approach with lasting success while a larger superior fistula was subtotally occluded and will requirefurther transarterial and direct puncturetechniques. Conclusions: Ophthalmic vein fistulae area rare form of dural arteriovenous fistulaewith presenting symptoms mimickingthose of carotid cavernous fistulae.Ophthalmic vein fistulae can often be successfully treated via transvenousembolization with resolution of presentingsymptoms.

207. The use of Intracranial Stents for theTreatment of Broad Neck AneurysmsRafael Rodriguez-Mercado, MD, FACS; VeronicaHernandez-Burgos, MD; Vivian Hernandez-Burgos, MD; Waltter Kravcio, MD (San Juan, PR)

Introduction: The treatment of broad neckaneurysms had advance with the introduc-tion of the intracranial stents. By there usethe neck of this aneury s m s can be remodelallowing the embolization with coils andpreserving the lumen of the parent vessel. Methods: We exam the clinical data of 15patients that underwent embolization ofaneurysms with wide neck that requiredthe use of Neuroform intracranial stentsbetween October 2003 to July 2004. Wetreat 11 (73%) women and 4 (23%) males.The average of age was 50 years old andthe neck diameter average was 6.0 mm.Results: We are able to deploy 16 stents.One patient required 2 stents due to the f o rward movement on deployment from the position that was intended. In 2 patients(13.3%) we saw thrombus formation thatrespond to aggressive anticoagulation andin one case (6.6%) we saw a stenosis ofthe parent vessels along the stent in anasymtomatic patient at 3 months control .No recanalization of the aneurysms waspresent.Conclusions: The use of 3D angiographyhelp to measure with precision theaneurysm dome, neck and parent vesseldiameter that are important variables todecide the size of stent . In our series atthis moment the only complications thatwe experience was problem of deploymentin tortuous anatomy and thrombus forma-tion . We need follow up and experience atlong term on the outcome of this patientsto decide if this the better treatment forbroad neck aneurysms.

208. Mechanical Clot Removal Therapy inAcute Embolic Stroke PatientsTakahisa Mori, MD, PhD; Keisuke Imai, MD;Hajime Izumoto, MD (Kamakura, Japan)

Introduction: It depends on the volumeand composition of clots embedded in thevessel whether successful recanalization isachieved with localized intraarterial fibri-nolysis (LIF) or percutaneous transluminalcerebral balloon angioplasty (PTCBA) intreatment of acute embolic stroke patients.The purpose of our study was to investi-gate the feasibility, safety, and effective-ness of a mechanical clot removal therapy:MCRT in treatment of acute embolic strokepatients with total occlusion of the carotidartery (CA) or proximal middle cerebralartery (MCA).

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P OSTER PRESENTATION ABSTRACTSMethods: Patients with serious neuro-logical symptoms due to embolic totalocclusion of the CA or proximal MCAinappropriate to LIF or PTCBA under-went MCRT with a stainless microbas-ket Soutenir, for the intracranial arteryand In-Time for the carotid artery.Clinical outcome was evaluated withmodified Rankin Scale:mRS at 3months after MCRT.Results: Five hundreds twenty-ninepatients suffering acute ischemicstroke were admitted consecutively toour institution from December 2002 toApril 2004. Among them, six patientsunderwent MCRT. We succeeded inretrieving the clots from the intracranialartery in two and from the CA in onepatient. Among three patients with successful retrieval of clots, completerecanalization was achieved by inter-rupting blood flow of the proximal CAduring removal with coaxial ballooncatheter in two. In two patients withcomplete recanalization, 3-month mRSwas 1 or less, while 5 or more in 4patients without complete recanaliza-tion. No procedural complicationsoccurred.Conclusions: MCRT may be feasible,safe and effective to achieve completerecanalization and good clinical out-come even in patients inappropriate toLIF or PTCBA.

209. Localization of Small VascularMalformations With a Radio-OpaqueWire Localizer: Technical NoteQuoc-Anh Thai, MD; Gustavo Pradilla, MD;Rafael J. Tamargo, MD, FACS (Baltimore, MD)

Introduction: Small vascular malfor-mations, such as arteriovenous malformations, arteriovenous fistulae,and small peripheral cerebral aneury s m scan be difficult to localize intraopera-tively. We describe a simple and accurate intraoperative angiographically-assisted localization technique that addsv i r t u a l l y no cost, set-up time, or poten-tial for technical errors. Methods: Patients (2 AVMs, 1 AVF, 1aneurysm) had routine pre-operativediagnostic imaging and evaluations.Once the patients were anesthetized, aninterventional neuroradiologist cannu-lated the femoral artery and preparedfor intraoperative angiography, which is standard at our institution.Craniometric landmarks were then utilized to approximately localize thelesion. For precise localization of thelesion, a radio-opaque wire localizer

(OWL) was placed over the proposed craniotomy site and an angiogram wasperformed. Using real-time angiogra-phy, the OWL was manipulated untilthe small vascular lesion was visualizedentirely within the OWL frame, thusaccurately outlining the extent of therequired craniotomy and the surgicaltrajectory.Results: The OWL was used to localizesmall vascular lesions intraoperativelyin two cases of left parietal arteriove-nous malformation, a case of left parietal arteriovenous fistula, and acase of left M3 6mm fusiform aneury s m.In all four cases, the lesion was accu-rately localized intraoperatively withoutfurther image-guided techniques, andthere was a minimal craniotomy. Therewere no intraoperative complications,and the patients all had uneventfulrecoveries. Conclusion: The radio-opaque wirelocalizer with intraoperative angiogra-phy can effectively aid in the planningof surgery in small vascular lesionswith virtually no added cost, set-uptime, or potential for technical errors.

210. Induction of Apoptosis in Glioma cellsIn Vivo by Inhibition of ATF5Michael A. Weicker, BSC; James Angelastro,PhD; Peter Canoll, MD, PhD; Lloyd Greene,PhD; Jeffrey Bruce, MD (New York, NY)

Introduction: ATF5 is a bZip transcrip-tion factor that acts as a negative permissive regulator of gene transcription through suppression ofcAMP response element transactiva-tion. ATF 5 is upregulated in malignantgliomas, including human and ratglioma cell lines and surgically resected GBMs. It is absent in matureneurons and glia and has been shownto prevent the differentiation of neuralprogenitor cells. We investigated thepotential to inhibit tumor growth in arat glioma model by disrupting ATF5with a dominant negative mutant. Methods: C6 rat glioma cells wereinjected into the striatum of maleFisher rats. At day 10 post-injection,retrovirus encoding either a dominantnegative ATF5 (AZIP) or eGFP control,both at ~1.25x104 PFU in 5 µl, wasintroduced into the tumors. Animalswere sacrificed on post-injection day13. Brains were fixed in 4% PFA, cryoprotected in 30% sucrose and 10µm cryostat sections obtained. Sectionswere stained with TUNEL, labeled withantiGFP antibody and nuclei were visual-ized with Hoechst dye.

Results: 215/225 (96%) of cellsinfected with ATF5 within the tumors(n=5) were TUNEL (+) while less than1% (2/252) of the infected cells in ani-mals that received retrovirus with eGFP(n=5) were TUNEL (+). Additionally,only 1/63 (2%) of AZIP infected cellsoutside of tumors were TUNEL (+).Conclusions: Disruption of ATF5 function through retroviral delivery of a dominant-negative mutant results in apoptotic tumor cell death in a ratglioma model with no deleteriouseffects on surrounding normal b r a i ntissue. This novel anti-tumor strategyhas potential important clinical a p p l i c a t i o n s.

211. Evaluation of Different ManualTechniques for Calculating SystemMagnification Factor for AngiographicMeasurement of Intracranial VesselsArshad U. Siddiqui, MD; Afshin A. Divani,PhD; Crystal R. Tholany, BS; Ammar Alkawi,MD; Muhammad S. Hussain, MD; Jawad F.Kirmani, MD; Adnan I. Qureshi, MD(Newark, NJ)

Introduction: During angiographic procedures, the actual size of an artery is estimated by applying themagnification factor (MF) obtainedfrom a known object in the x-ray field to the image size of the artery.Accurate measurement of an artery iscrucial during angioplasty or stentplacement procedures. An evaluation of one- and two-marker methods tocalculate MFs for intracranial vesselsize is presented here. Methods: To evaluate each method,a phantom mimicking the size of thehuman head was constructed. Imagesof the phantom in lateral and A-P projections were acquired for differentlocations of a lesion within the phan-tom. Forty three intracranial vessels of17 patients were measured using thesame techniques.Results: To evaluate each method, aphantom mimicking the size of thehuman head was constructed. Imagesof the phantom in lateral and A-P projections were acquired for differentlocations of a lesion within the phan-tom. Forty three intracranial vessels of17 patients were measured using thesame techniques.Conclusions: Linear interpolation ofinverse magnification using a two-marker method can lead to a moreaccurate estimate of the size of a lesioncompared to linear interpolation ofdirect magnification. The use of one94

external marker to determine MF of alesion target can lead to errors that maycomplicate a therapeutic endovascular procedure. High quality image acquisitionwith minimum distortion can result in betterassessment of vessel size.

212. Early Single Center Results PolyvinylAlcohol Spherical Particles for Pre-Operative Tumor EmbolizationMatthew Adamo, MD; Eric M. Deshaies, MD; A. John Popp, MD; Alan S. Boulos, MD (Albany, NY)

Introduction: Polyvinyl alcohol (PVA) particles are used for tumor embolization of vascular lesions prior to extirpation toreduce intraoperative blood loss and m o r b i d i t y. Unlike PVA microspheres, P VA particles have a tendency to congealmaking the embolization particles large andless likely to penetrate the distal microvas-culature of the tumor; this prevents effectivetumor embolization. Currently, there are noreports about the use of PVA micros-pheres for the pre-operative embolization of intracranial tumors, so we present ourexperience with seven patients. M e t h o d s : Seven patients with angiographicevidence of a tumor blush underwent PVAmicrosphere embolization; tumor extirpa-tion was performed within 48 hours. Wereviewed perioperative complications, intraoperative blood loss, length of operation, and need for blood transfusions. R e s u l t s : Five intracranial meningiomas, one glomus jugulare tumor, and one nasofi-broangioma were successfully embolizedwith PVA microspheres. There was oneintraprocedural tumor hemorrhage requir-ing emergent surgical tumor extirpation and a second who developed twelfth nerv edysfunction; both had complete neurologi-cal recovery post-operatively. Intraoperativeblood loss and operative time were reducedcompared to non-PVA microsphereembolizations. No unusual intraoperativecomplications occurred attributable to PVAmicrospheres. D i s c u s s i o n : R e c e n t l y, PVA microspheres(700-900 microns) were used to embolizevessels in miniature porcine kidneys andinduce end-organ infarction. Microscopicevaluation of the specimens revealed amilder inflammatory response than withother embolization particles. We used PVAmicrospheres to embolize 7 tumors withgood results and demonstrated that intra-operative blood loss and operative timewere reduced. In addition, several nuancesin technique for particle and microcatheterselection are altered in comparison to PVAparticles.

213. A Comparison of Micrus Bare Platinumand Cerecyte Coils in a Canine ModelGoetz Bendorff, MD; Tetsu Satow, MD; LanceReinsmith, BS; Charles M. Strother, MD(Houston, TX)

Introduction: Modification of coils withpolymers to enhance cellular in growthand organization thrombus has been proposed. Our purpose was to compareMicrus bare platinum coils with modified(Cerecyte, Micrus) coils in a canineaneurysm model. Methods: One bifurcation and one side-wall aneurysm was created in each of 10canines. One of the two aneurysms wascoiled using either bare platinum orCerecyte coils. Each aneurysm was coiledas completely as possible using standardtechniques. Follow-up angiograms wereobtained at 3 months. Aneurysms wereexplanted and sent for histopathology after6-month angiograms.Results: There was no difference inmechanical properties between both typesof coils. Compared to the immediate post-treatment angiograms all 4 side-wallaneurysms, treated with Cerecyte, werestable or improved, while 2 of 4 treatedwith bare platinum were worse. As com-pared to the immediate post-treatmentangiograms 3 of 5 bifurcation aneurysmstreated with Cerecyte were stable while all5 treated with bare platinum were worse.There was no significant change betweenthe 3-month and 6-month angiograms.Multiplanar measurements using 3D-datarevealed no significant compaction even inthe aneurysms that recurred.Conclusions: In this model, the Cerecytecoils were associated with a better out-come than were the bare platinum coils.The absence of coil compaction may be ofsignificance.

214. Use of Frameless Stereotaxy for DistalIntracranial AneurysmsArun P. Amar, MD; Ty Thaiyananthana, MD;Murat Gunel, MD (New Haven, CT)

Introduction: While aneurysms arising inproximity to the circle of Willis are usuallyeasy to locate at surgery, those emergingfrom more distal arterial segments can behard to find. We report the utility of frame-less stereotaxy in the surgical manage-ment of peripherally-situated cerebralaneurysms. Methods: As part of our protocol for subarachnoid hemorrhage, 3 patients withruptured intracranial aneurysms under-went computed tomography angiography(CTA) upon admission. Two patients had

a small (3-mm) aneurysm located on distal (M3 or M4) branches of the middlecerebral artery, including one mycoticaneurysm due to subacute bacterial endo-carditis. The third aneurysm arose from anA4 branch of the anterior cerebral artery.Catheter angiography disclosed that noneof the aneurysms were amenable toendovascular repair. The patients under-went craniotomy guided by the BrainLabframeless stereotaxic system. Surface registration from CTA data was performedwithout fiducials using the Z-Touch device.No extra preoperative imaging wasrequired.Results: In each case, BrainLab navigation aided in planning the scalp incision and craniotomy flap, developingthe surgical corridor, and localizing theaneurysm within subarachnoid cisterns.Microdissection and brain retraction wereminimized as a result. The two MCAaneurysms were fusiform and requiredexcision; the ACA aneurysm was treatedby clip reconstruction. All patients recovered well.Conclusions: The absence of visible land-marks and familiar corridors impede thelocalization of aneurysms arising from distal cerebral arteries. Using data fromstandard CTA protocols, frameless stereo-taxic navigation may facilitate the surgicalmanagement of these aneurysms.

215. Correlation Between TranscranialDoppler and Cerebral Angiography inPatients With Subarachnoid HemorrhageNikolaos I.H. Papamitsakis, MD; HenrikManassarians, MD; Mohammad Sajed, MD;Michael Moussouttas, MD (Edison, NJ)

Introduction: Transcranial doppler sonog-raphy (TCD) has been used for monitoringof vasospasm in patients with subarach-noid hemorrhage (SAH), although cerebralangiography (CA) remains the gold stan-dard for the diagnosis of vasospasm. Methods: This was a retrospective studyof 11 patients with SAH. 10 were women.Mean age was 61.8 (40-77). All patientshad CA and TCD, which was performedwith an EME Pioneer device using a stan-dard examination technique. The arteriesinsonated included both middle cerebral(MCA), anterior cerebral (ACA), intracranialinternal carotid (ICA), vertebral (VA) andthe basilar artery (BA). TCD performedclosest to CA were reviewed. In 7 patientsthe studies were performed within a periodof 3 days and in 4 patients within a month.The maximum mean flow velocities(MMFV) in the vessels insonated with TCD were reviewed. The degree of vessel

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P OSTER PRESENTATION ABSTRACTSstenosis on CA was estimated basedon WASID criteria.Results: 70 vessels were insonatedand identified with TCD and CA. 13vessels were not insonated with TCDand 18 were not imaged with CA. 2 of70 vessels were found to have graterthan 50% stenosis on CA and theirMMFV were elevated: 133 cm/sec foran MCA, and 75 cm/sec for a BA. In 5vessels (MCA and ACA) the MMFVwere greater than 100 cm/sec, withoutcorresponding stenoses or vasospasmon CA.Conclusions: TCD was a sensitive butnot specific test for the evaluation ofvasospasm in patients with SAH in thisstudy. Information from larger series isneeded to confirm these findings.

216. Serum Calcium Levels FollowingCerebral AngiographyMuhammad S. Hussain, MD; Ameer Hassan,BA; Asad Khan; Farys Chaudry; Amer M.Hussain, MSc; Pansy Harris-Lane, NP (Newark, NJ)

Introduction: Cerebral angiographyutilizes ionic and non-ionic contrastagents injected intra-arterially to v i s u a l i z e the cerebral vasculature. One commonly used agent is Visipaque,which includes the chelating compoundedetate. Thus, the potential exists forfluctuations in electrolyte levels, including calcium, when this agent isadministered. Methods: The pre-angiography andpost-angiography serum calcium levelsresults of 87 consecutive patients werereviewed and analyzed. Patients weregrouped based on when the post-angiogram serum calcium level wasdrawn (0-6hr, 6-12 hr, 12-18 hr, and18-24 hr).Results: Two patients had serum calcium levels drawn greater than 24hours after their angiogram and werethus discarded. Statistically significant(p less than 0.05) differences betweenthe pre-angiogram and post-angiogramserum calcium levels were found in the0-6 hr, 6-12 hr, and 12-18 hr groups(0.91 mg/dL, 0.59 mg/dL, and 0.55mg/dL, respectively). The difference inthe 18-24 hr group (0.27 mg/dL) wasnot statistically significant. None of thepatients were clinically symptomaticfrom this decrease in serum calcium.

Conclusions: An asymptomatic butsignificant decrease in serum calciumis seen following cerebral angiographyusing the Visipaque contrast agent. The decrease is temporary, appearingto resolve within 24 hours. This is animportant finding to note, as thedecreased serum calcium levels shouldsimply be observed over time to see ifthey recover, provided the patient isasymptomatic.

217. Embolization of Swine Retia Mirabilia(RMs) Experimental ArteriovenousMalformation (AVM) Models WithNon-adhesive Liquid EmbolicMaterial: Eudragit PolymerHideki Arakawa, MD; Corrine R. Davis,DVM; Diane L. Howard, RVT; Wendy L.Baumgardner, RVT; Huy M. Do, MD(Stanford, CA)

Introduction: Eudragit polymer, a non-adhesive and DMSO free liquid embolicmaterial, is used for endovascularembolization of swine AVM models.Acute and chronic angiographic andhistopathological responses of swineRMs after embolization were assessed.Methods: Eudragit (copolymer ofmethyl and butyl methacrylate anddimethylaminoethyl methacrylate) wasdissolved in 50% ethanol and 50%iopamidol. Eudragit was injected intonine RMs. Ethanol and iopamidol mix-ture and n-BCA were injected into fourand two RMs, respectively, for compar-ison. Three RMs were used as con-trols. Three RMs embolized withEudragit mixture were evaluated bothangiographically and histopathologicallyacutely (3 to 6 hours), and at 1-monthand 3-months after embolization.Results: No procedural complicationsfrom Eudragrit embolization were noted,including retention or adhesion of them i c r o c a t h e t e r. Various degrees ofinflammation were observed in the acuteand 1-month specimens. Two RMsshowed partial recanalization upon bothhistopathology and follow-up angiogra-phy in the 1-month group. Arterial fibro-sis and calcification were observed inthe 1 and 3-month specimens. Theinternal elastic lamina was disrupted in the chronic specimens, but withoutevidence of extravasation of Eudragit orhemorrhage. Endothelial damage wasseen all specimens and was particularlysevere in the chronic specimens. The RMs injected with ethanol andiopamidol mixture showed minimalinflammation and endothelial stripping.

Conclusions: Eudragit polymerinduced favorable inflammation forthrombosis similar to n-BCA, but with-out the disadvantages of perivascularhemorrhage and extravasation ofembolization material. Although partialrecanalization of some embolized RMswas noted, further investigation intoEudragit as a potentially useful embolicmaterial for brain AVMs is warranted.

218. Effects of Lamina TerminalisFenestration and Cisternal BloodRemoval Over Hydrocephalus andVasospasm in Aneurysmal SAHJorge M. Mura, MD; David I. Rojas, MD(Providencia/Santiago, Chile); Luis CarlosVintimilla, MD (Cuenca, Ecuador); AlvaroRuiz, MD; Patricio Loayza, MD(Providencia/Santiago, Chile)

Introduction: Lamina terminalis fenes-tration (LTF) has became an importantneurovascular tool in the microsurgeryof ruptured intracranial aneurysm. Itseffects over hydrocephalus are welldocumented in the current literature.Nevertheless, the association of LTFwith cisternal oppening and clotremoval (COCR) in the acute phaseaneurysmal SAH microsurgery and itseffects over vasospasm are not wellknown. Methods: We present the results ofour prospective non-randomizedendovascular controlled study of highgrade SAH related hydrocephalus andvasospasm. A series of patients operat-ed in the acute phase of aneurysmalSAH in whom a LTF and wide COCRwere performed is analyzed.Results: As previous published reports,LTF diminished the shunt dependanthydrocephalus. The association withCOCR has a positive effect over thepermanent neurological deficits sec-ondary to vasospasm.Conclusions: LTF and COCR are techni-c a l l y demanding but essential steps inthe microsurgery of aneurysmal SAH.A modern concept of microneuro-surgery for ruptured intracranialaneurysms must include LTF and COCRin the patients with high grade SAH,besides the classical clipping forrebleeding prevention.

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219. Initial Experience With Cerecyte CoilsMicrus for Treatment of IntracranialAneurysmsPedro Lylyk, MD; Juan Miranda, MD; AngelFerrario, MD; Leandro Haas, MD; Francisco E.Villasante, MD; Jairo Fernández, MD (BuenosAires, Argentina)

Introduction: Describe the early clinicalexperience of newly designed coils for theendovascular treatment of intracranialaneurysms , their compatibility and theshort angiographic follow up results . Material and Methods: Between June andJuly 2004, 6 patients were treated withcerecyte micrus coils with 7 aneurysms (3 SAH, 2 symptomatic and 2 incidentals).Age range 25 to 68 years (mean: 44,8years). The anatomical variables foundedand the characteristics of the treatment toendovascular were reviewed. The functionaland angiographic outcome route 30 daysfollow-up was achieved.Results: 6 patients, 5 female, 1 male,aged 25 to 68 (mean age 44,8). The mostcommon location was the anterior circula-tion n=6 (85,8%) and posterior 1 cases(14,2%). 1 giant aneurysm, 1 large, 5small. The global morbimortality rate was0 %. 3 aneurysms were controlled by DSAat two months with stability of cast decoils and improvement of occlusion.Conclusions: In this initial experience thebehavior of the coils were, without frictioninside the microcatheter and very smoothlike bare regular coils. Long time follow upis needed to evaluate the healing process.

220. Predictors of Bleb/Thin Wall Formation inUnruptured Aneurysmal Sac WithoutPrevious Subarachnoid HemorrhageByung Y. Choi, MD, PhD; Chul Chang, MD;Sang Kim, MD; Seong Kim, MD, PhD; Oh Kim,MD, PhD; Soo Cho, MD, PhD (Daegu, Republicof Korea)

Introduction: In decision making for management of unruptured intracranialaneurysm, bleb/thin wall of sac is animportant factor, but it's not easy to find it out preoperatively. This study is under-taken to clarify predictor(es) of bleb/thinwall of sac in unruptured aneurysms. Methods: The authors reviewed radiologicstudy, operative slide film and/or videotape in 53 patients with unrupturedaneurysms without evidence of previoussubarachnoid hemorrhage who underwenttranscranial treatment in our hospital fromDec. 1988 to Dec. 2003 and analyzed therelationship between bleb/thin wall forma-tion in intraoperative finding and preopera-tive radiologic finding.

Results: Among 53 patients, 22 (42%)had both of bleb and lobulation, 9(17%)has lobulation only without bleb, 5(9%)had bleb only without lobulation, and 17(32%) had neither of bleb and lobulation.There was statistic significance(p less than 0.01) between bleb/thin wall and lobulated sac.Conclusions: Unruptured aneurysmshowing lobulations in angiogram wouldbe a possible prodictor of bleb/thin wallformation of sac.

221. The Effect of Clot Soluble Components onCoagulation Response During anEndovascular Thrombectomy ProcedureArshad U. Siddiqui, MD; Afshin A. Divani, PhD;Crystal R. Tholany, BS; Ali P. Ebrahimi, PhD;Charles R. Spillert, PhD; Sara K. Michael, BS;Adnan I. Qureshi, MD(Newark, NJ)

Introduction: The focus of treating acuteischemic stroke has been on rapidlyreestablishing normal blood flow to theischemic area. During a thrombectomyprocedure, the thrombus undergoes radialstress while being retrieved into thecatheter potentially causing release of itssoluble components into the blood streaminducing a prothrombotic state. The effectsof the soluble components on re-thrombo-sis are reported in this study.Methods: To monitor changes in coagu-lopathy, swine blood was used in a mockcirculation. Four blood samples weredrawn at different stages of the thrombec-tomy procedure in five experiments. Threesamples, withdrawn after introducing thethrombus, were treated with variousthrombolytic agents. A Sonoclot was usedto examine the changes in coagulationresponse.Results: Clot formation onset time forcontrol, before, during, and after clotretrieval were 146 plus or minus 53sec,114 plus or minus 28sec, 129 plus orminus 33sec, and 116 plus or minus 40,respectively. Clot formation rate was 25plus or minus 9, 37 plus or minus 6, 32plus or minus 14 and 36 plus or minus 19,r e s p e c t i v e l y. Maximum clot viscosity was112 plus or minus 40, 113 plus or minus27, 120 plus or minus 21, and 110 plus orminus 11, respectively. The same indiceswere obtained after addition of Lovenox,Reteplase, and Reapro to the samplesrevealed changes consistent with theirrespective mechanisms of action.Conclusions: Trends show that solublefactors released into circulation during theprocedure induce a hypercoaguable state.Lovenox may have the effect of prolonging

the onset of clot formation duringthombectomy. However due to the sparse nature of the dataset, no statisticalconclusion was drawn. More evaluationand a greater sample size will be needed to achieve statistical significance and todetermine the effects of thrombolyticagents on the hypercoaguable state.

222. Treatment of Acute Basilar ArteryThrombosis With Intra-Arterial ReteplaseRichard M. Berger, MD; James A. Homan, MD;Kim K. Clothier, PA-C (Wichita, KS)

Introduction: Basilar artery thrombosis, ifuntreated, carries a mortality rate of over80%. We present a series of 5 patientstreated at our institution with intra-arterialreteplase. Methods: We have treated 5 patients overa 2 year period with intra-arterial reteplasefor acute basilar artery thrombosis. Theages of the patients were 22, 26, 32, 53and 61. Time from onset of symptoms to treatment ranged from a few hours toalmost 4 days. Low dose heparin wasadministered during each procedure. Onepatient required basilar artery angioplastyfor an underlying stenosis, and anotherrequired rescue with abciximab when thebasilar artery re-thrombosed after com-plete recanalization with reteplase.Results: All patients presented as locked-in or nearly locked-in state. Completerecanalization was obtained in all 5patients with 4 of the 5 achieving a Rankinscore of 2 or better. One patient who wastreated within hours of time of onset had asmall unilateral pontine hemorrhage andremained locked-in.Conclusions: Basilar artery thrombosisshould be ruled out in the setting of acuteloss of consciousness, including youngpatients, and may be safely and effectivelytreated even days after onset of symptomswith intra-arterial reteplase.

223. Intraventricular Hemorrhage due toSinovenous Thrombosis in Full-TermNeonate With a Duplex ThrombophilicGenetic Mutation and Congenital ProteinC DeficiencyTumbiolo Silvana, MD; Fiumara Ettore, MD;Gioia Francesco, MD; Sammarco Piero, MD;Filizzolo Felice, MD (Palermo, Italy)

Introduction: Sinovenous thrombosis(SVT) is a rare disease in the newbornwith cerebral infarction (50%) or intraven-tricular hemorrhage (IVH) (33%). The etiology of neonatal SVT is multifactorial:deficiencies of protein C, protein S,antithrombin, mutation of factor V Leiden

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P OSTER PRESENTATION ABSTRACTS(FVL), substitution of G with A at position 20210 of the prothrombingene. Less prevalent are other geneticmutations as methylenetetrahydrofolatereductase (MTHFR) C 677T genotype,plasmonigen activator inhibitor-1 (PAI-1) 4G/4G polymorphism or heterozygosy protein C deficiency.Case Report: This 16-day-old girl, full-term neonate, developed suddenonset of lethargy and vomiting, owingto an extensive IVH with hydrocephalus.The magnetic resonance imaging andthe magnetic resonance angiographyshowed a sagittal sinus thrombosis.The laboratory studies were normalexcept a low protein C level. The geneticstudies showed MTHFR C677T muta-tion and homozygosity for the PA I - 14G/4G. The patient was submitted toexternal ventricular drainage and after aventriculoperitoneal shunt was applied.At six month follow-up the patient didn’tpresent neurological deficit and theneuropsychiatric test was normal. Results: In our case the less level ofprotein C associated with a duplexgenetic mutation (MTHFR and PAI-1)can be the cause of SVT with secondaryI V H .Conclusions: Therefore all termneonates with IVH should undergo to neuroimaging studies to evaluate the presence of SVT. In these cases laboratory studies are mandatory.Subsequently the genetic studies servefor the identification of an inheritedthrombophilia but shouldn’t preclude asearch for other less prevalent factors,because in some cases more risk factors are associated, as in our case.

224. The Utility of Three DimensionalComputerized TomographyAngiography and Magnetic ResonanceAngiography in Comatose PatientsWith Bleeding ArteriovenousMalformationsFiumara Ettore, MD; Tumbiolo Silvana, MD;Gioia Francesco, MD; Pisciotta Maurizio,MD; Pizzuto Antonio, MD (Palermo, Italy)

Introduction: The mortality rate ofcomatose patients harboring intracere-bral hematoma (ICH) is about 60%. An early surgery can improve outcome.Three dimensional computerizedtomography angiography (3DCTA) andmagnetic resonance angiography(MRA) could be useful for a rapid diag-nosis of arteriovenous malformation(AVM) in comatose patients with ICH.

Methods: In the last 4 years,11 patientswith sopratentorial ICH, due to AVM,were surgical treated in our depart-ment. Six conscious patients, beforeelective surgery, were submitted toMRI and DSA, because AVM surgery iscarried out as an elective procedure.But 5 comatose patients were submit-ted to emergency surgery without DSA,with the aid of 3DCTA in 4 cases andMRA in a pregnant patient. Results: In these 5 cases the surgicalprocedure could begin within 90 min-utes from presentation. At operation asmall AVM together with the clot couldbe removed. Postoperative DSA didn’tshow any residual AVM. Three patientshad good recovery and 2 had severedisability.Conclusion: DSA has been always considered the gold standard in thediagnosis of vascular malformations.Nevertheless it's a time-consumingexam. In life-threatening ICH 3DCTA issuperior to DSA but also to MRA interms of shorter time to define vascularlesion. In comatose patients improvingoutcome is possible if the clot evacua-tion is timely, avoiding DSA, whichshows everyone of AVM features, butwhich is time-consuming. If 3DCTAshows a small AVM, neurosurgeon cantend towards both hematoma and AVMremoval. But if AVM is large, onlyhematoma must be removed.

225. Relationship Between Plasma BrainNatriuretic Peptide and CerebralVasospasm After AneurysmalSubarachnoid HemorrhageCarlos A. David, MD; Ronald Riesenberger,MD; Vasilos Zerris, MD (Burlington, MA)

Introduction: Data suggest that plas-ma BNP concentrations increase inpatients with cerebral vasospasm. Thisstudy was undertaken to evaluate thetime course and relationship betweenvasospasm, TCD velocities, SerumSodium, and plasma BNP.Methods: Prospective data collectionon 8 patients with aneurysmal SAH.Data included daily plasma BNP, sodi-um, TCD velocities, and clinicalvasospasm onset. A BNP ratio wasdeveloped using the average BNP ondays 1to 4 divided by days 7-11.Results: The average BNP ration for 3 patients with no clinical or TCD evi-dence of vasospasm was 0.79. Theaverage BNP ratio in 5 patients withclinical vasospasm was 3.69.

Conclusions: The data suggest that plasma BNP increases in associationwith the onset of vasospasm.

226. Radiation Induced IntracranialAneurysmGabriel A. Gonzales-Portillo, MD, FACS;Juan M. Valdivia, MD; Goetz Roederer, MD;Anne Herbst, MD (Tucson, AZ)

Introduction: Radiation-inducedintracranial aneurysm is a rare but wellrecognized condition however, patho-genesis remains speculative. We reportthe case of a pediatric patient with aruptured intracranial aneurysm, whopreviously received radiation therapy tothe orbits. Methods: The charts of patients whounderwent craniotomy and clipping ofintracranial aneurysms from July 1999to June 2004 were reviewed. Medlinesearch of the English literature wasconducted from 1964 to 2004.Results: A 12 year old boy with a ruptured right ACA aneurysm was identified. He had radiation therapy tothe orbits for recurrent retinoblastomasduring infancy. His aneurysm was 2mm in size and arised from the wall ofthe ACA. Three years follow up CTangiogram was negative for newaneurysms in the contralateral circula-tion. We found 14 reported cases of intracranial aneurysms located in a previous radiated field. Ten cases pre-sented with subarachnoid hemorrhage.Mortality in this group was 70% (noneunderwent definitive treatment of the ruptured aneurysm except one whohad embolization). The survivors (3patients) include 2 patients who under-went craniotomy and clipping, and onepatient in which the aneurysm under-went spontaneous thrombosis. Therewere four patients with unrupturedaneurysms. All underwent craniotomyand clipping.Conclusions: Vascular abnormalitiesincluding aneurysm formation due toendothelial injury has being describedafter radiation therapy to the brain.Intracranial aneurysms located in aprevious radiated field can arise fromthe wall of the parent vessel and canrupture at a small size. Due to its highmortality when ruptured, it should betreated when diagnosed.

227. Withdrawn

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228. ePTFE Covered Stent Repair of CervicalCarotid DisruptionMohammed A. Aziz-Sultan, MD; SamyElhammady, MD; Stacey Quintero, MD; HassanY. Tehrani, MD; Alois Zauner, MD (Miami, FL)

Introduction: Pseudoaneurysms and acuteinjuries to the cervical segment of the carotidartery represent true medical emergencieswith limited surgical treatment options. Wereport the endovascular repair of cervicalcarotid artery disruptions in three cases,using Viabahn expanded polytetrafluoreth-ylene covered stents. ePTFE has been usedextensively in peripheral vascular work anddisplays good patency rates. We were ableto maintain parent vessel patency, whileobliterating a pseudoaneurysm, an arteri-ovenous fistula, and a carotid rupture. Methods: Patient 1 presented with dys-phagia and an enlarging, pulsatile neckmass causing tracheal deviation. Patient 2 presented with a zone two neck stabwound, resulting in a hematoma, sur-rounding the carotid artery sheath and apuncture of the common carotid artery.Patient 3 presented with multiple gunshotwounds to the abdomen and neck. Thepatient was found to have a high flowcarotid artery to jugular vein fistula. AViabahn graft was placed in all threepatients, using the femoral artery forendovascular access. All patients receivedPlavix for 1 month and Aspirin indefinitely,starting at the day of procedure.Results: In all cases we were able to treatthe life threatening carotid artery disrup-tions, while maintaining normal antegradeflow. No immediate neurological or embol-ic complications were encountered. TheViabahn graft remained patent in all threepatients at the most recent examinations,3-6 months after treatment.Conclusions: Early results demonstratethe usefulness of the ePTFE covered stentgrafts for endovascular reconstruction ofthe carotid artery. However, the long termresults of these new techniques have notyet been established.

229. A Novel Technique for Localization of anAngiographically Occult Spinal DuralArteriovenous FistulaRodney S. Allan, FRACS; Stephen P. Lownie,MD; Irene B. Gulka, MD; Donald H. Lee, MD(London, ON Canada)

Introduction: Spinal dural arteriovenousfistulae are usually diagnosed on MRI andlocalized using selective spinal angiogra-phy. Occasionally, however, the location ofthe fistula cannot be identified despite ade-quate angiography. We present a novel

method of surgical localisation which wassuccessfully utilized in the setting of anegative angiogram. Methods: A 29 year old male presentedwith a rapidly progressive myelopathy.MRI and MRA with contrast enhancementrevealed a dural arteriovenous fistula.Thorough spinal and cerebral angiographyfailed to reveal the location of the fistula.Exploratory lower thoracic laminectomyrevealed an engorged, red vein on the dorsal aspect of the spinal cord. Results: The draining vein was temporarilyoccluded to determine whether the loca-tion of the fistula was rostral or caudal tothe point of occlusion. Caudally, the veinturned blue, while cranially it remaineddistended and red. Accordingly, thelaminectomy was extended cranially andthe fistula was identified entering the dura at the T5 level, and subsequently disconnected. Conclusion: This technique may be usefulin cases of dural arteriovenous fistulaewith negative angiography. In the case presented, a potentially devastating neuro-logic outcome was successfully averted.

230. Delayed Traumatic Carotid ArteryDissection After Normal CT Angiography:A Case ReportAdnan H. Siddiqui, MD, PhD; Michael Park, BS;James W. Holsapple, MD (Syracuse, NY)

Introduction: Carotid artery dissection is asignificant and potentially treatable causeof neurologic injury after trauma. Fracturesthrough the carotid canal raise suspicionfor arterial injury. CT angiography is aneffective tool for screening and evaluatingintracranial vascular disease. Here wepresent a case of a negative CT angiogram,which was followed 10 days later by a dissection of the left carotid artery thatresulted in a large hemispheric stroke. Methods: A retrospective analysis of a case presentation with a review of literatureResults: A 15 year old female wasinvolved in an MVA with a left frontaldepressed skull fracture for which she underwent a decompressive craniecto-my. Workup revealed skull base fracturesincluding one involving the left carotidcanal. A CT Angiogram of the head andneck revealed normal carotid and vertebralvasculature. 10 days later a follow-up CTscan revealed a large left hemisphericstroke. Repeat CT angiography revealeddissection and severe narrowing of the leftpetrous carotid in the region of the priorfracture. Retrospective analysis did notreveal any evidence of intimal injury in earlier study.

Conclusions: We present a case thathighlights the potential for inadequacy ofCT angiography in detecting minor intimalinjury especially in the region of thepetrous carotid. Although we do not knowif conventional digital subtraction angiog-raphy would have revealed an intimalinjury, it does raise that prospect. Wetherefore propose that CTA may be usedas a screening tool however, if negativeand in face of significant suspicion, a DSAshould be performed.

231. Quantitative Assessment of CollateralBlood Flow in Arterial Circle of the BrainRouben V. Fanardjyan III, MD, PhD; HovhannesM. Manvelyan III, MD, PhD (Yerevan, Armenia)

Introduction: Collateral Blood Flow(ColBF) is most impressive factor in occlusion development in cerebral vessels. We investigated 32 patients withCarotid-Cavernous Fistula (CCF) in age 6-64 years, TBI ethiology, Cerebral BloodFlow (CBF) was evaluated with Tr a n s c r a n i a lDopplerography (TCD). CCF modelselected to reveal potential possibilitiesColBF to accomplish infringements of CBF,as informative in different phases of brainischemia in cases of all infringements,prior disturbances of brain depends oncondition of ColBF. Unique possibilities ofendovasal angioplastics allows performquantitative assessment of CBF treatment.The integral level of flow (IFL) characteristicof ColBF compensatory possibilities isindex of flow symmetry in M1 CMA.Depending of outburst from the A.Carotisinto Cavernous Sinus level extent of IFL-M1 and asymmetry in main CoBF ways allpatients were divided two groups: 1. 12patients with IFL-M1 normal range, less15%. Decreasing of CBF by the main CoBFways reach up 60% matching with contra-lateral flow, and succeeding ACA, PCA andOphtalmic Artery. 2. 20 patients had asymmetry over 15% in M1. Revertiveflow velocity in CoBF reached up to200% matching with contra-lateral flow.Involvement of CoBF was analogous asACA, PCA and OA. There is a strong correlation between TCD and angiographyresults. Reconstructive surgeries leads torestoration of symmetry of CBF in M1 andmain CoBF, deconstruction in all types ofCCF increase asymmetry flow in V1 andmore active involvement of CoBF.

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P OSTER PRESENTATION ABSTRACTS232. Sapphire Platinum Detachable Coil

Experience in a Tertiary Care CenterAbutaher M. Yahia, MD (East Lansing, MI);Vicki Gordon, NP; Richard D. Fessler, MD(Detroit, MI)

Introduction: Recently, sapphire platinum detachable coil (Micro- Therapeutic, Inc.) is introduced in neurointerventional practice, but thereare little data available regarding theiruse. To report a single center clinicalexperience in sapphire detachable coil in the treatment of aneurysm andA-V fistulas (AVF). Methods: Consecutive patients fromJanuary 2004 to June 2004, whounderwent embolization of aneurysmor AVF with sapphire detachable coilswere enrolled. Patient's demographics,clinical grades and aneurysm locationswere collected.Results: 28 patients underwent sapphire coil embolization, in which 26were aneurysm (54% ruptured) and 2were AVF. Mean age was 51 plus orminus 18 (mean plus or minus SD)years and 82% were female. Arteriallocations of the aneurysm were as fol-lowing; internal carotid 7, basilar 6,anterior communicating 5, posteriorcommunication 5, middle cerebral 1,posterior cerebral 1 and pericllosalartery in1patient. Aneurysm neck wasreconstructed in 6 cases, 5 with neuro-form stent and 1 with balloon. All stentassisted coiling were staged. In 5 casessapphire coil was mixed with othercoils and in 2 cases it was used withglue. Technical success was achievedin all cases. There was no thromboem-bolic evens during coil embolization. Inone case, coil fractured when used withglue. In 4 cases coil stretched duringstent assisted coiling. Completeaneurysm occlusion was achieved in49%, neck remnant in 40% and partialcoiling was achieved in 11%.Conclusions: Sapphire detachable platinum coil is safe in embolization ofaneurysm and AVF. It is not associatedwith thromboembolic events, but asso-ciated with stretching of coil whenused with stent.

233. Coil Embolization of RupturedHypoglossal Artery AneurysmsArun P. Amar, MD; Michael Stoffman, MD;Murat Gunel, MD (New Haven, CT); DonaldLarsen, MD; George Teitelbaum, MD;Michael Wang, MD (Los Angeles, CA);Michele Johnson, MD (New Haven, CT)

Introduction: The persistent primitivehypoglossal artery (PPHA), firstdescribed in 1889, represents the remnant of a carotid-vertebrobasilaranastamosis that fails to regress during embryogenesis. Although rare(incidence of 0.025%), it is frequentlyassociated with anomalies of theintracranial vasculature, includinganeurysms of the circle of Willis. Lesscommonly, aneurysms may arise fromthe PPHA itself, either at its origin fromthe cervical internal carotid (ICA) or at its connection with the vertebral orbasilar arteries. The transcondylar andother skull base approaches to theselatter lesions are challenging, due tothe jugular tubercle and lower cranialnerves that intervene. Because of theseanatomical features, clip ligation isoften unsuccessful or associated withhigh morbidity. We report the firstknown successful coil embolization ofa ruptured PPHA aneurysm. Methods: Two young women presentedwith subarachnoid and intraventricularhemorrhage. Both underwent angiography, which revealed a PPHA in association with a saccularaneurysm at its connection to the vertebrobasilar junction. Both patientsunderwent successful coil embolizationof the PPHA aneurysm.Results: Both made a good neurologicalrecovery and were discharged withoutany cranial nerve palsies. Follow-upa n g i o g r a p h y confirmed aneurysm conclusion.Conclusions: We report the firstknown cases of coil embolization for ruptured PPHA aneurysms.Endovascular therapy may reduce themorbidity of the treatment typicallyrendered for this condition.

234. Intracranial Angioplasty in a YoungAdult With Graves Disease andMoyamoya DiseaseStanley H. Kim, MD, PA; Anant I. Patel, MD,PA; Kent T. Ellington, MD; Marylyn Kajs-Wyllie, RN, MSN, CCR (Austin, TX); AdnanI. Qureshi, MD (Newark, NJ);

Introduction: Cerebral ischemic eventshave been described in patients withGraves disease and Moyamoya diseaseor Moyamoya phenomenon. Theauthors describe the first reported caseof intracranial angioplasty for sympto-matic intracranial internal carotid artery(ICA) stenosis in a patient with Gravesand Moyamoya diseases. Methods: A 33-year-old Hispanicfemale with a history of Graves diseasepresented with a right hemiparesis thatresolved over a week. A magnetic reso-nance imaging (MRI) study of the brainrevealed ischemic changes in the leftparietal-occipital region. A cerebralangiogram revealed severe bilateralsupraclinoid ICA stenosis with a net-work of basal collaterals consistentwith Moyamoya disease. We performedangioplasty of the left supraclinoid ICAusing a 2 x 9 mm Maverick balloon(Boston Scientific Corp, Natick, MA)without any peri-procedural complica-tions. The patient was discharged on325 mg of aspirin and 75 mg of plavixdaily.Results: Seven months later, thepatient underwent a follow-up cerebralangiogram that revealed mild left supr-aclinoid ICA stenosis with resolution of adjacent basal collaterals. Severestenosis of right supraclinoid ICAremained. We performed angioplasty of the right supraclinoid ICA using thesame balloon without complications.The patient remained asymptomatic atthe ten month follow-up evaluation.Conclusions: Our case adds to the listof rare cases of concurrent Graves andMoyamoya diseases. Further studiesare needed to determine the relation-ship between these diseases.Intracranial angioplasty should be considered as an alternative treatmentto prevent ischemic complications inthese patients.

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235. The Superior Opthalmic Vein Approach toCavernous Carotid Fistulae TechniqueRevisitedKetan R. Bulsara, MD (Columbia, MO); Eren Erdem, MD (Little Rock, AR)

Introduction: Endovascular techniqueshave revolutionized the treatment of cavernous carotid fistulae via transarterialand transvenous routes. In some circum-stances, however, traditional endovascularapproaches may fail. Direct access to thesuperior ophthalmic vein (SOV) can beused to treat fistulae in this circumstance. Methods/Results: A curvilinear incision is made in the superior nasal eyelid. A microdoppler is utilized to assist inlocalizing the SOV. A small angiocathetheris introduced into the SOV.Discussion: Direct access to the SOV stillremains an option for the treatment of cavernous carotid fistulae when other conventional methods cannot be utilized.

236. Temporal Lobectomy for IntractableEpilepsy. Technical ReportJuan M. Valdivia Valdivia, MD; Martin Weinand,MD, FACS (Tucson, AZ);

Introduction: Temporal Lobectomy is aneffective mean of treating medically refrac-tory partial-complex epilepsy of temporallobe origin. Besides a correct planning andpatient selection, the review of the anato-my and surgical steps of the procedure iscrucial for adequate results and avoidanceof devastating complications. Methods: One hundred TemporalLobectomy procedures were recorded.Videos from these cases were reviewed foracademic purposes and learning. Reviewof the literature regarding the evolution ofthe technique and anatomical landmarks of the procedure were also performed. The steps of the surgical technique wererevised pointing vital structures and theirpreservation.Results: A text depicting each step of theprocedure and a comprehensive five-minute video were developed. Each stepwas described with the objective of everysurgical maneuver.Conclusions: The procedure is donethrough a pterigonal craniotomy.Important landmarks during the approachare the sylvian fissure, the sphenoid ridge,the temporal horn and the posterior cerebral artery, among others. Adequatetemporal lobectomy technique entails care-ful preservation of vital structures such asthe posterior cerebral artery, third cranialnerve and cerebral peduncle. Adequatewhite matter, amygdala and hippocampal

resection during temporal lobectomy isguaranteed in order to interrupt the onsetof temporal origin complex partialseizures.

237. Zygoma-Sparing Submandibular-Infratemporal Interpositional SaphenousVein Graft Bypass for the Treatment of aMalignant Skull Base Tumor: TechnicalNoteAminullah Amini, MD, MSc; James K. Liu, MD;William T. Couldwell, MD, PhD (Salt Lake City, UT)

Introduction: Cerebral revascularizationwith an interpositional saphenous veingraft (SVG) bypass may be a useful strategy for the management of somecomplex skull base tumors and aneury s m s.A zygomatic osteotomy is usually p e rformed when executing a submandibularcarotid-saphenous vein bypass. Wedescribe a modified zygoma-sparingapproach performed on a 55-year-old manwith a complex skull base nasopharyngealcarcinoma involving the cavernous sinusand petrous bone. Methods: Radical resection of the tumorwas achieved through a frontotemporalc r a n i o t o m y. The internal carotid artery (ICA)was sacrificed, requiring reconstructionwith an interpositional high-flow bypass.The high cervical ICA was initially exposedand mobilized inferiorly, and an end-to-endanastomosis was performed using anSVG. The graft was then tunneled througha burr hole created in the floor of the middle fossa via a submandibularinfratemporal route. The zygoma and related muscle attachments were leftintact. The distal SVG was then cut inproper length and attached to the oph-thalmic segment ICA using an end-to-endanastomosis. A radial forearm free flapwas used for skull base reconstruction. A complete total resection of the tumorwas achieved. Postoperative angiographydemonstrated patency of the graft. Therewas no postoperative cerebrospinal fluidleak. Conclusions: Direct submandibularinfratemporal interpositional SVG bypasswas performed without removal of zygo-matic arch or detachment of the masseteror temporalis muscle insertions. This technique provides a direct and shorterroute for revascularization, which helpspromote graft patency and preserves normal facial anatomy.

238. Vascular Inflammation With EosinophilsAfter the use of TRUFILL [n-ButylCyanoacrylate (n-BCA)] Liquid EmbolicSystemAida Baisre, MD; Neelesh Mittal; Leroy R.Sharer, MD; Eun-Sook Cho, MD (Newark, NJ);Charles Hunt, MD; Jeffrey Farkas, MD (NewYork, NY); Charles J. Prestigiacomo, MD(Newark, NJ)

Introduction: TRUFILL n-ButylCyanoacrylate (n-BCA) was approved by the FDA in September 2000 forembolization of cerebral arteriovenousmalformations (AVMs) when presurgicaldevascularization is desired. The mostcommon histopathological changesencountered in tissues where this productis used are neutrophils in the acute phase,and lymphocytes, macrophages and for-eign body giant cells around the glue inthe chronic phase. We report three casesin which there was extensive mural inflammation including eosinophils involving the AVM vessels. Methods: Three patients with mean age of 33 years underwent staged embolizationand later resection of the AVMs, with inter-vals of 3, 5 and 18 months. Specimenswere submitted for pathological examina-tion by paraffin-embedded, H&E-stainedstandard sections. Results: Histological evaluation demon-strated the expected findings of foreignbody giant cell reaction surrounding theembolic material within occluded vessels,with lymphocytes and hemosiderin-ladenmacrophages. Of particular interest wasthe presence of transmural inflammationof vessel walls with numerous eosinophils.In one of the cases, there was suggestionof fibrinoid necrosis. This occurred in a patient who sustained a fatal hemorrhageshortly after the second stage embolization. Conclusion: We believe this is the firstseries documenting the presence ofeosinophils as part of the inflammatoryresponse following the use of this andother cyanoacrylates in patients and experimental animals. An investigation into the matter with a larger series is indicated, to clarify whether this inflam-matory reaction may play a role in patientoutcome or complications.

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P OSTER PRESENTATION ABSTRACTS239. Case Report: Endovascular Treatment

of a Giant, Fusiform Basilar AneurysmMohammed A. Aziz-Sultan, MD; SamyElhammady, MD; Andrew Jea, MD; RobertoC. Heros, MD; Alois Zauner, MD (Miami, FL)

Introduction: Giant fusiform basilarartery aneurysms are increasingly recognized, leading frequently to unfavorable outcomes. Common therapeutic options include proximalocclusion and bypass procedures.However, major branches may directlytake off the aneurysm, therefore preventing the obliteration of theaneurysm. We present a case of a 1 5 - y e a r-old female with a giant fusiformbasilar aneurysm, incorporating the origin of the left AICA. The endovasculartreatment of obliterating the aneurysmwhile preserving the AICA is presented. Methods: After successful balloon testocclusion of the vertebral arteries and evidence of retrograde flow to the PCA and SCA via the posterior communicat-ing arteries, we proceeded to endovas-cularly occlude the proximal basilarartery and vertebral arteries, distal tothe origins of the PICA. We used amethod of selecting both vertebralarteries simultaneously to provide extrasecurity in preventing distal displace-ment of the coil mass.Results: Serial follow-up angiogramsover a period of one year showed grad-ual thrombosis of the aneurysm withpreservation of the AICA.Postoperatively, the patient had fewepisodes of dysmetria and dizziness,attributable to aneurysmal thrombosis,as demonstrated on CT and angiogram.The anticoagulant and antiplatelet man-agement played an important rolethroughout the treatment period.Conclusions: With the growing recog-nition of fusiform basilar aneurysmsand their poor natural history, there isneed for improved therapeutic options.We demonstrate a case, which repre-sents an alternative technique to opensurgery. The present case highlightsthe natural stages of aneurysm throm-bosis and vessel branch preservationand reiterates the importance of properanticoagulant and antiplatelet therapythroughout the treatment period.

240. The "White Collar Sign" in theEndovascular Embolization ofIntracranial AneurysmsNestor R. Gonzalez, MD; Yuichi Murayama,MD; Reza Jahan, MD; Gary Duckwiler, MD;Yih-Lin Nien, MD; Neil A. Martin, MD;Fernando Vinuela, MD (Los Angeles, CA)

Introduction: A new angiographic finding in patients with intracranialaneurysms embolized with Matrix coilsis described. The correlation of thisfinding with prior histopathologicalstudies and its significance in the treatment of intracranial aneurysms are analyzed. Methods and Results: Two illustrativecases are reported. Case-1 is a 15 -year-old female with a iatrogenic leftinternal carotid artery aneurysms aftercraniotomy for suprasellar tumorresection. Case-2 is a 49-year-old male with SAH secondary to an A-comaneurysm. Bioactive Matrix coils wereemployed for the treatment of bothcases, obtaining adequate packing ofthe aneurysm. Follow-up angiograms,12 months (case-1) and 8 months(case-2) after treatment demonstrateda well-defined radiolucent (“white” inDSA) separation between the coil massand the parent artery in both cases.This is the first report in humans ofthis finding, which has not seen beforein the embolization of aneurysms withstandard GDC coils. The "white collarneck” finding resembles what we haddescribed in prior animal studies andpossibly represents the formation ofneointimal tissue at the neck level. Conclusions: A new radiological finding, the “white collar sign”, characterized by a well-defined, radiolucent gap at the neck of theaneurysm, separating the aneurysmallumen from the parent artery afterembolization with Matrix coils, represents a complete isolation of theaneurysm from the circulation. Basedon prior histopathological studies, thissign may indicate the formation of athick connective tissue barrier betweenthe aneurysm and the artery that prevent any further filling of theaneurysm lumen.

241. Pediatric Proliferative Angiopathy Resembling Brain AVMsPaula Klurfan, MD; Thorsteinn Gunnarsson,MD, MSc; Derek Armstrong, MD; Karel Ter Brugge, MD (Toronto, ON Canada)

Introduction: The spectrum ofintracranial AV shunts includes a variety of poorly recognized and distinguished entities which may mimicAVMs. One such condition, proliferativeangiopathy, can be associated withhemorrhagic events. Methods: Cases where analyzed noticing A-V shunting from normalsized arteries into normal sized veins in cerebral angiograms and a diffusenidus witch on MRI examination show normal brain tissue in betweenabnormal vascularity.Results: The angiographic and MRIfindings were found to be clearly distinct from the common type ofAVMs and indicate a separate clinicalentity requiring different treatmentstrategies.Conclusions: Discussion is focused on pattern recognition at cerebralangiography and MRI imaging in order to avoid pitfalls in diagnosis and eventual treatment.

242. Endovascular Reconstruction forTreatment of DissectingPseudoaneurysm of Cervical InternalCarotid Artery With Covered StentsEugene H. Kang, MD; Eric W. Pierson, MD;Benjamin R. Gelber, MD (Lincoln, NE)

Introduction: We describe two casesof covered-stent placement for dissect-ing pseudoaneurysm of the cervicalinternal carotid artery. In one case, thisprocedure allowed us to preserve theparent vessel and provided access totreat an incidental left middle cerebralartery aneurysm. Method: We treated three patients with dissecting pseudoaneurysm of the cervical internal carotid artery.Using a percutanous trans-femoralroute, cerebral angiogram and 3Dreconstruction images were obtained.Patients were given aspirin 81 mg andclopidogrel 75 mg orally, at least 3days before the procedure and for 4 to6 weeks post-procedure. After place-ment of a 6F guiding catheter at thecervical internal carotid artery, heparinwas administered intravenously toachieve an activated clotting time of250 - 300 seconds. An exchange guidewire was navigated beyond the

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aneurysm using biplane fluoroscopicroadmap guidance. The covered stent wasplaced at the neck of aneurysm, thendeployed across the involved carotid cervi-cal aneurysm. Control cerebral angiogramand CT scans of the brain were obtainedpost-procedure. Results: Covered stents were placed in thedesired position in two cases. In one case,the covered stent could not be placed inthe desired location due to extreme tortuosity. This patient was treated withcoil embolization with remodeling tech-nique. Two-month follow-up angiogramsshowed complete occlusion of thepseudoaneurysms and preserved parentvessels and stents. No periproceduralcomplications occurred in this series. Conclusion: With our limited short-termfollow-up, endovascular reconstructionwith covered stent is a promising and safetechnique to treat dissecting pseudoa-neurysm of cervical carotid artery.

243. Ruptured Aneurysm of the ChoroidalBranch of the PICA: Case Report, Reviewof the Literature and ProposedPathogenesisNancy McLaughlin, MD; Michel W. Bojanowski,MD, FRCS(C) (Montreal, PQ Canada)

Introduction: Aneurysms rarely occur at the choroidal branch of the posterior inferior cerebellar artery (PICA). Theirpathogenesis is not well-understood. Methods: Case report and review of the literature.Results: A 69-yr-old female was admittedfor a sudden onset of severe headachewith nausea and vomiting. Soon afterarrival, she became less responsive. Ahead CT-scan revealed an intraventricularhemorrhage (IVH) predominantly in the4th and 3rd ventricles with hydrocephalusand without subarachnoid hemorrhage.Cerebral angiography demonstrated ananeurysm at the choroidal branch of thePICA. The aneurysm was resected througha transvelotonsillar approach. The patientmade a remarkable recovery. The literaturedescribes 5 other cases of aneurysms aris-ing from a choroidal branch of the PICA.Hypertension was a common finding.Conclusions: Aneurysms arising from achoroidal branch of the PICA are rare.Hypertensive vessel damage might be amajor factor in their pathogenesis. Wepropose that this aneurysm represents ahypertensive aneurysm which can accountfor some isolated spontaneous IVH.

244. High-Flow Bypass Between the Vertebraland Middle Cerebral Arteries PreventsProgressive Neurological DeteriorationCaused by the Left Common CarotidArtery Occlusion: Case ReportMasahiko Akiyama, MD (Atsugi City, J a p a n ) ;Hiroyasu Kamiyama, MD (Asahikawa, Japan);Satoshi Tateshima, MD; Yuzuru Hasegawa, MD,PhD (Atsugi City, Japan)

Introduction: This study reports a patientwith a progressive stroke, caused by theleft common carotid artery occlusion, whounderwent extracranial-intracranial high-flow bypass surgery using a radial arterialgraft between the vertebral artery ((VA), V3segment) and the middle cerebral artery((MCA), M2 segment). Sixty-seven-year-old lady who presented one-week historyof dysarthria and motor weakness in theright face and arm was admitted to ourhospital. The initial MRI showed a newischemic lesion in the deep white matter of the left frontal lobe. Angiogram demon-strated the left common carotid arteryocclusion without any cross circulationsfrom the anterior or posterior communi-cating arteries. The left carotid arterysystem was mostly supplied by collateralcirculations from the contra lateral externalcarotid artery system. Computed tomo-graphic (CT) perfusion study indicatedsevere misery perfusion in the left frontaland temporal lobes. As the symptomsdeteriorated by her baseline blood pres-sure, we diagnosed that the patient had asevere hemodynamic stroke caused by theleft common carotid artery occlusion andthe left internal carotid artery system needed reconstruction. Six weeks after the initial attack, V3-M2 radial artery grafthigh-flow bypass surgery was performed.Postoperative angiogram confirmed suffi-cient blood flow through the radial bypassgraft into the ipsilateral internal carotidartery system. Improved cerebral bloodflow in the left frontal and temporal wasconfirmed by CT perfusion study. No clinical signs of further deterioration of ischemia were observed p o s t o p e r a t i v e l y.This V3-M2 bypass appears to be an effective means of preventing catastrophicischemia from the common carotid arteryocclusion.

245. Extracranial Carotid-Jugular FistulaeTreated With Endovascular CoilingChul-Hoon Chang, MD; Byeong-Yeon Choi,MD; Sang-Woo Kim, MD; Sung-Ho Kim, MD;Oh-Lyong Kim, MD; Soo-Ho Cho, MD; Woo-Mok Byun, MD (Daegu, Republic of Korea)

Introduction: The incidence of arteriove-nous fistulae (AVF) in head and neck lesionis less than 4% of all traumatic AVFencountered elsewhere in the body.Extracranial carotid-jugular fistulae (CJF)after penetrating injury at neck is rareclinical condition. The authors present acase of extracranial CJF which was treatedwith endovascular method. Methods: A 6 years old male patient was admitted to our hospital with chiefcomplain of progressive headache, pulsating mass, and hard thrill at the rightside of neck region for 3 months. He hadpenetrating neck injury 9 months ago.During the latent period, he had no specificsymptom. 3-dimention CT angiogram anddigital subtraction angiogram revealedarterivenous fistulae between distal common carotid artery, sublingual artery,and internal jugular vein. Fistulous tractand right retromandibular vein weremarkedly dialted. Right intracerebral vascular structures were poorly visualizeddue to high flow arteriovenous shuntResults: For therapy, we choose an coilembolization. Through internal and externaljugular vein, microcatheter were insertedto the dilated fistula tract, it was embolizedwith platinum and fibered coil sparing theinternal jugular vein. After embolization,there is no abnormal venous drainage andwell-visualized right intracerebral vascularstructures.Conclusions: During the follow up period,he complains of transient mild neck painand preoperative symptoms and signs weredisappeared. Endovascular coiling for traumatic extracranial carotid-jugular fistula is a good treatment modality.

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P OSTER PRESENTATION ABSTRACTS246. Treatment of Giant Cerebral

Aneurysms by EC-IC Bypass andAneurysmal Coil EmbolizationShaye I. Moskowitz, MD, PhD; MichaelChow, MD; Thomas J. Masaryk, MD; PeterA. Rasmussen, MD (Cleveland, OH)

Introduction: Successful management of giant aneurysms presents significantdifficulty when trying to preserve distalcerebral flow while occluding theaneurysm. One management schemeincludes distal vessel bypass and par-ent artery occlusion. Direct hunterianligation of the cervical or intracranialcarotid and endovascular balloon trap-ping have been the techniques utilizedfor their efficacy. The use of directedcoil embolization and EC-IC bypassmay offer the advantage of securingdistal cerebral flow and aneurysmexclusion, while preserving small proximal branches neighboring theaneurysm. Methods: A case series of giantintracranial aneurysms treated with EC-IC bypass and endovascular coiling.Results: Two cases of ruptured giantMCA aneurysms are presented. Bothpatients demonstrated inadequate distal MCA perfusion with parent vesselocclusion and were treated with EC-ICbypass and directed endovascular coiling. Proximal and distal brancheswere preserved utilizing this technique.Successful exclusion and distal perfu-sion were confirmed on follow-upangiography months post-treatment.Conclusions: These patients demon-strate the feasibility to treat giant complex aneurysms by EC-IC bypassand coil embolization. This offers theadvantages of coil embolization, distalpreservation of blood flow, and sparingcritical proximal branching vessels thatmight be sacrificed with hunterian ligation or balloon trapping.

247. Vein of Galen AneurysmalMalformation Presenting WithPulmonary Hypertension AssociatedWith Portal-Hepatic A-V ShuntPaula Klurfan, MD; Dorota Stasiak; WilliamHalliday, MD; Charles Smith, MD; GailReintamm, BSN, RN; Karel Ter Brugge, MD(Toronto, ON Canada)

Introduction: Pulmonary Hypertensionis a rare but not uncommon associa-tion with Vein of Galen AneurysmalMalformation (VGAM) witch can easilyconfound the management strategy.The cause of pulmonary hypertensionunder this circumstance is poorlyunderstood. Methods: We report an infant that had developed Congestive Heart Failure (CHF) and pulmonaryhypertension successfully managedwith endovascular treatment at neonatal age.Results: Eventual worsening of clinicalconditions resulted in death. Autopsyfindings conclude that the pulmonaryhypertension was caused as a conse-quence of a portal-hepatic A-V Shuntand not with the VGAM.Conclusions: Clinical implications andmanagement choices will be discussed.

248. Early Endovascular Management ofIntra- and Extracranial AV FistulasPresenting With Congestive HeartFailurePaula Klurfan, MD; Shinichi Nakano, MD;Ronit Agid, MD; Gail Reintamm, BSN RN;Karel Ter Brugge, MD (Toronto, ON Canada)

Introduction: Management of neonatespresenting with Congestive HeartFailure (CHF) associated with intracra-nial A-V Shunt may require earlyendovascular treatment in face of failing optimal medical therapy.Methods: We report the managementof a 2.0 Kg. neonate presenting withsevere CHF associated with Vein ofGalen Aneurysmal Malformation as well as the management of a high flowV-V Fistula presenting at neonatal agewith CHF.Results: Successful technical management of the A-VF's resulted insignificant improvement of the CHFsymptoms.Conclusions: Technical difficulties atthis early age may preclude activetreatment. Low weight Newborns represent yet another challenge as faras access and fluid management isconcerned. Extracranial V-V Fistulaehave not been previously regarded tobe associated with CHF at birth.Implication for management ofneonates with severe Congestive HeartFailure associated with high flow AVSwill be discussed.

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