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INTERVENTIONAL NEURORADIOLOGY Journal of Peritherapeutic Neuroradiology, Surgical Procedures and Related Neurosciences Official Journal of the World Federation of Interventional and Therapeutic Neuroradiology Official Journal of the Japanese Society of Neuro-Endovascular Therapy

Index Editorials

M. Leonardi

3

P.L. Lasjaunias

5

Endovascular Treatment of Brain Arteriovenous Malformations: the Toronto Experience

A. Valavanis

9

P. KLURFAN, T. GUNNARSSON, C. HAW, K.G. ter BRUGGE

Embolization as one Modality in a 57 Combined Strategy for the Management of Cerebral Arteriovenous Malformations

Original Articles: Glue Based Embolization

Therapeutic Management of Cerebral Arteriovenous Malformations. Present Role of Interventional Neuroradiology

13

F. VIÑUELA, G. DUCKWILER, R. JAHAN, Y. MURAYAMA

Brain Arteriovenous Malformations (BAVMs) in Thailand: Therapeutic Experience and Clinical Outcomes in Ramathibodi Hospital

30

S. PONGPECH, P.J. IARAKONGMUN, S. GEIBPRASERT

Management of Brain AVMs at Bicêtre: a Comparison of Two Patient Cohorts Treated in 1985-1995 and 1996-2005

31

A. OZANNE, H. ALVAREZ, G. RODESCH, P. LASJAUNIAS

Endovascular Treatment of Cerebral Arteriovenous Malformations with Emphasis on the Curative Role of Embolisation

37

L. PICARD, S. BRACARD, R. ANXIONNAT, A. LEBEDINSKY, S. FINITSIS

J. RAYMOND, D. IANCU, A. WEILL, F. GUILBERT, J.P. BAHARY, M. BOJANOWSKI, D. ROY

Combined Treatment of Brain AVMs: Analysis of Five Years (2000-2004) in the Verona Experience

63

A. BELTRAMELLO, P. ZAMPIERI, G.K. RICCIARDI, E. PIOVAN, A. PASQUALIN, A. NICOLATO, R. FORONI, M. GEROSA

Endovascular Treatment of AVMs in Glasgow

73

J.J. BHATTACHARYA, S. JENKINS, P. ZAMPAKIS, M. BEHBAHANI, E. TEASDALE, V. PAPANASTASSIOU

Intra-arterial Embolization in the Analysis of Five Years (2000-2004) in the Treatment of Brain Arteriovenous Malformations

81

J. CAMPOS, L. BISCOITO, P. SEQUEIRA, A. BATISTA

A. VALAVANIS, A. PANGALU, M. TANAKA

Brain AVM Embolization. Retrospective Study concerning 728 Patients Followed between 1984 and 2004

51

45

Ectatic and Occlusive Diseases of the Venous Drainage System of Cerebral Arteriovenous Malformations (AVMs) with Emphasis on Specutacular Shrinking Neurological Deficits After Embolization

95

K. GOTO www.centauro.it

Indexed in: EMBASE / Excerpta Medica; WFNRS - Libray of the SIIC - Sociedad Iberoamericana de Información Científica; ISI - Institute for Scientific Information: Neurosciences Citation Index ®, ISI Alerting Services ®, and Science Citation Index ® - Expanded (SciSearch ®)


The Characters of Images and Endovascular Embolization for High Risk Cerebral AVM

119

LI SHENG, LI BAOMIN, WANG JUN, CAO XIANGYU, GU XIAOFANG, GUO LIPING

Brain Arteriovenous Malformation 125 (bAVM): Technical Note of Endovascular Treatment with Glubran® A.H. DESAL, F. TOULGOAT, S. RAOUL, B. GUILLON, R. AL HAMMAD IBRAHIM, E. AUFFRAY-CALVIER, A. DE KERSAINT-GYLLY

Basics and Principles in the 131 Application of Onyx LD Liquid Embolic System in the Endovascular Treatment of Cerebral Arteriovenous Malformations R. SIEKMANN

Endovascular Treatment of Cerebral AVMs with a New Material: Onyx®. Partial Results

165

J. TEVAH, I. HUETE

Endovascular Treatment of Cerebral AVM with Onyx-Initial Experience

171

S. JOSEPH, H.C. CHADAGA, K. MURALI

Clinical Analysis of 50 Cases of BAVM Embolization with Onyx, a Novel Liquid Embolic Agent

179

DONGLEI SONG, BING LENG, YUXIANG GU, WEI ZHU, BIN XU, XIECHENG CHEN, LIANGFU ZHOU

Brain AVM Embolization with Onyx®: Analysis of Treatment in 34 Patients

185

M. LEONARDI, L. SIMONETTI, P. CENNI, L. RAFFI

Original Articles: Onyx Based Embolization

A. PÉREZ-HIGUERAS, R. ROSSI LÓPEZ, D. QUIÑONES TAPIA

159

L. PIEROT, A. C. JANUEL, D. HERBRETEAU, X. BARREAU, J. DROUINEAU, J. BERGE, N. SOUROUR, C. COGNARD

Original Articles: Technical Notes

Endovascular Treatment of Cerebral AVM: Our Experience with Onyx®

Endovascular Treatment of Brain Arteriovenous Malformations Using Onyx: Preliminary Results of a Prospective, Multicenter Study

141

Call for the 2006 Membership Fee

205

WFITN Application Form

206

Instructions to Authors

209


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Interventional Neuroradiology 11: 3-4, 2005

Dear Friends, This splendid supplement to Interventional Neuroradiology, devoted to the Neuroradiology of Arteriovenous Malformations, offers me the chance to recall some of our milestones on the tenth anniversary of the journal’s publication. Having decided to found a journal dedicated to interventional and therapeutic neuroradiology, I explored a number of solutions and contacted different publishers to assess the feasibility of the project. My experience gained as Editor-in-Chief of Rivista di Neuroradiologia, founded in 1988, convinced me that complete independence from any commercial publishing house was the only way to guarantee maximum editorial freedom and freedom from the economic constraints which led many, albeit authoritative journals to close. My prime aim was to establish a point of reference for publication of our work and dissemination of our scientific skills and offer colleagues a forum for news and views on all aspects of this fascinating new field. Equally important was to emphasize that interventional and therapeutic activities are integral parts of neuroradiology today. The journal’s name reflected what could already be termed diagnostic and therapeutic neuroradiology, diagnostic knowledge being a prerequisite to clinical and interventional neuroradiological practice. I found the best possible Editor-in-Chief in Pierre Lasjaunias. We have known each other since 1973 when I was in Paris training in angiography under the late Prof. René Djindjian. We have become firm friends sharing ideas, dreams and projects. What more could one ask of friendship? We have worked together very hard, first for the ESNR - European Society of Neuroradiology, the ECNR European Course in Neuroradiology, devised and implemented by Pierre, followed by the ESNR Advanced Course, producing myriad publications. All this came together with the project for Interventional Neuroradiology to which we have devoted our evenings and weekends for the past decade. As Pierre recalls in his editorial, we presented the first issue of Interventional Neuroradiology to the WFITN Congress in Kyoto in 1995. The outcome was important for two reasons. Firstly, Interventional Neuroradiology was accepted by the WFITN and JSNET as their official journal. Secondly, publication in English of studies by Japanese colleagues is one of the achievements we are most proud of: their excellent work, the proceedings of their important annual meetings, had previously been

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Dear Friends

precluded to colleagues without Japanese. I am deeply indebted to Makoto Negoro for his ongoing support and help in JSNET’s contribution to the journal which has given all of us greater insights into the fascinating world of Japan. The journal has not been without its hurdles, namely the usual problem of how to cover the costs. Relations with our sponsors have not always run smoothly and in some cases the publication of “undesirable” papers led to withdrawal of sponsorship for a number of years. An anecdote illustrates my policy in dealing with potential sponsors. When manufacturers would say they failed to see the use of publishing advertisements in Interventional Neuroradiology because it would not have boosted sales, I would retort that their contribution has only the semblance of advertising: a page in Interventional Neuroradiology serves as graphic testimony of a company’s support; we are in the realm of patronage, advantages are indirect but as the sector grows, so will its field of activity with knock-on economic advantages. On the whole, the contributors grasped the message and granted the necessary advertising for which we all are grateful: publisher, editor, authors and readers. We have nonetheless had a resounding success in defending what must be any journal’s most important asset: its complete scientific and editorial independence. Nowhere is this plainer than in the current issue: it is sponsored by ev3 the producers of Onyx, recently FDA approved, and we are very grateful, but it is a long way from being a targeted semicommercial publication. The articles reflect the authors’ scientific views, freely expressed and subjected only to peer review by the ad hoc scientific editor Anton Valavanis. I have many people to thank for helping me in this task: first and foremost Pierre Lasjaunias, Anne Collins for English editing, Doriano Angeli for outstanding printing and production work and Elisabetta Madrigali for following in his footsteps. I also thank Pierre’s secretary Sylvie Lelièvre, all the authors of the 739 articles published, all the manufacturers who have supported us, and my wife Adriana for allowing me to devote countless hours to this wonderful project.

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Interventional Neuroradiology 11: 5-7, 2005

I

nterventional Neuroradiology 1995-2005: 739 Articles

It was Marco Leonardi who, during the summer of 1995 at the WFITN world congress in Kyoto, first had the idea of starting the Journal of Interventional Neuroradiology, and that a few weeks later became a reality. The link with the East has been one of the journal’s features ever since. In the time that has elapsed from Kyoto to Venice, as well as the Society’s meetings, we have seen: • 52 editions of our Journal; • of which 5 concomitant with WFITN programmes, and 8 JSNET supplements; • 739 articles (300 on aneurysms); • for a total of 6013 printed pages As a vehicle of human communication, science must be intelligible to everyone while not stifling specific intellectual and cultural characteristics in the attempt. The dialectic used to convince, be convinced, assess or experiment hypotheses differs in Asian, Middle-Eastern and Western cultures. Yet the quality and commitment of research coming from other cultures are as strong as those provided by Western evidence-based medicine. Moreover, bio-ethnology, genetics, epi-genetics, risk factors or response to viruses, all make diseases, diagnoses, incidental findings and biological response to treatments different in different areas of the world. Science must always be humble, its aim to contribute to knowledge. To be creative, the scientist must be inquisitive; otherwise he remains a mere technical expert. What significance does a Journal or printed book have in an era of the Internet and SMS communication. “Scientific” literature has become so standard as to be disembodied: the scientific community has become a federation of interest groups that form and disband with the ebb and flow of wider strategic policies. This has led to the disappearance of innovation, creativity and altruistic research in the name of economic viability. And the applications of scientific contributions benefit solvent countries. For a scientific contribution to signify a true step forward, it has to be disseminated as something more than mere information. It is here that we see the exclusion of the have-nots, and the need and frustration this generates. These economic stakes reveal all too clearly the political role our scientific activity plays today.

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Editorial

The social framework and relevance of an activity will always be set by those with social and political responsibilities, and by the answers they provide to basic philosophical questions. The lack of training and practical standards in our field – and the vain attempts to achieve these, frustrated by negotiations among interest groups with little concern for the patient – are indicative of political shortcomings. In many editorials, Interventional Neuroradiology has stimulated debate on standards, ethics, its place in the clinical setting and statistical issues. WFITN’s training recommendations were first published in Interventional Neuroradiology 1 and became the basis for discussion on training in several continental organisations. As well as providing scientific contributions, Interventional Neuroradiology also reflects the wide diversity of materials and methods. Thanks to a core of devoted referees and Marco Leonardi’s dedicated editorial team, the Journal has been regularly published over the years, remaining dense, rich, objectively international and ethical. The Journal has steered clear of conflicts of interest. The Journal is the mouthpiece of the World Federation of Interventional and Therapeutic Neuroradiology and of the Japanese Society of Neuroendovascular Therapy. Today it is a major, widely recognised and indexed publication, with an impact factor that, despite its revamping, remains singularly high for a journal largely ignored by free-access online databanks. Everything free has a cost is a rule that also applies to information platforms. The label conferred by the title of a journal does not guarantee the long-term interest of the publication. EMBASE 2, a more complete database than Medline, makes available a much wider and more varied series of reports in the vascular sector, of fundamental interest to Interventional Neuroradiology. Using the keywords reference system, the databases index the journal’s articles extensively while the references are also loaded by End Note ®. Unfortunately, despite the undeniable interest these contributions make to the understanding of pathologies, only reports supported by data from large patient populations are taken into consideration. Yet concern for “statistical power” is no compensation for the vague knowledge it supplies, the standardisation of the doctor-patient

1998 WFITN: Guidelines for Fellowship Training Programmes in Interventional Neuroradiology. Interv. Neuroradiol. 4: 195-197, 1998. 2 EMBASE, Excerpta Medica, WFNRS, Library of the SIIC, ISI – Institute for Scientific Information: Neurosciences Citation Index ®. ISI Alerting Services ®, Science Citation Index ®- expanded (Scisearch ®). 1

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P.L. Lasjaunias


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Interventional Neuroradiology 11: 5-7, 2005

relationship, and the slipping from ethical considerations this encourages. It is the editorial board’s declared hope and wish to continue to promote the Journal, its high quality and open-mindedness. • The Journal aims to bring together specialists from all over the planet, remaining international for its reviews and contributors; • The Journal aims to demonstrate the lively curiosity required of the scientific world for all research endeavours; • The Journal aims to oppose endogamy- the consequence of fashions in approaches and technologies - and the development of interest groups, by ensuring an ample range of contributions; • The Journal intends to allow everyone a voice with open debates and opinions, provided these are ethically grounded; • The Journal aims to be the vehicle for the dissemination of quality, a basic tenet of participating societies and federations. We will never tire of recalling that science does not ask questions; it answers them. “Ph.D” stands for Doctor of Philosophy, the driver of all scientific investigations. Pierre Lasjaunias Editor-in-Chief

Founding the journal Interventional Neuroradiology: Michel Mawad, Luc Picard, Pierre L. Lasjaunias, Karel ter Brugge, Marco Leonardi; Kyoto November 21st, 1995 (photo by Nicola Leonardi).

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Interventional Neuroradiology 11: 9-12, 2005

C

erebral arteriovenous malformations (AVMs) undoubtedly represent one of the most challenging neurovascular lesions in the field of endovascular interventional neuroradiology. Despite significant advances which took place in the past two decades regarding their in-vivo visualization, the technology and methodology of the endovascular approach and in the contribution of functional angiographic and MR-imaging analysis to the understanding of their protean clinical behaviour, cerebral AVMs still remain enigmatic lesions in many aspects, which overshadow our ability to provide standardized and highly effective treatment with clinical outcomes comparable or superior to the natural history for most of them.

Cerebral AVMs are pathobiologically, angioarchitecturally and haemodynamically complex arteriovenous shunting systems with specific neurovascular relationships, a variable and mostly unpredictable clinical presentation and a dynamic but only partially understood natural history, associated with an annual bleeding rate of 2-4% and annual rates of severe morbidity of 1.7% and of mortality of 1%. With this special issue to be presented at the 7th Congress of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) taking place from 19th to 22nd October 2005 in Venice, Italy, the official journal of the WFITN “Interventional Neuroradiology” is celebrating its 10th anniversary. The editor-in-chief and the publisher decided to devote this special issue to the endovascular treatment of cerebral arteriovenous malformations and asked the undersigned to assist in the preparation of it. The endovascular treatment of cerebral AVMs started in the year 1960, when Luessenhop and Spence reported on the use of steel spheres covered with methyl methacrylate introduced into the surgically exposed internal carotid artery in order to block feeding arteries supplying a cerebral AVM calling this technique “artificial embolization”. In the subsequent 45 years the target of embolization of cerebral AVMs shifted from occluding feeding arteries to the obliteration of the nidus containing the av-shunts and significant progress in our understanding of the natural history, clinical manifestations, biological behaviour, the endovascular instrumentation, the materials, the neuroangiographic equipment and neurointensive care took place, so that today interventional neuroradiology fulfills a central and decisive role in the overall, complex, challenging and often multimodal management of patients with cerebral AVMs. In the first part of this issue several centers present and summarize the results of their experience with the endovascular treatment of cerebral AVMs and thus provide useful information on the evolution and current

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Editorial

state of the art. One conclusion which can be drawn from these articles is that there is a relatively high variability in the concepts applied and results obtained with the endovascular treatment of cerebral AVMs among different centers. For example, complete obliteration rate varies between 5.6% and 39% and the morbidity rate ranges between 1.4% and over 5%. This variability most probably reflects the persisting lack of understanding of the neurobiology of this disease and therefore the development of different concepts regarding the goals and targets of embolization among the different centers. The second part oft this issue includes several articles from different centers presenting their initial experience with the use of the new embolic material “Onyx” in the endovascular treatment of cerebral AVMs. Onyx is a nonadhesive liquid polymerising embolic material consisting of ethylene-vinylalcohol copolymer (EVOH), dimethyl sulfoxide (DMSO) and tantalum. Due to its longer polymerisation time and lack of adherence it permits theoretically slower filling and better penetration and obliteration of the nidus with less risk of gluing the microcatheter, as compared to N-butyl-cyanoacrylate (NBCA). Onyx is reported to be “easier” to handle and to use than NBCA mainly because it allows long lasting and interrupted injections without the fear of gluing the microcatheter within the vessel lumen and because it seems to be able to penetrate progressively into adjacent compartments obviating the use of multiple catheterizations. Furthermore, limited and initial experience with the use of Onyx in preoperative embolization of brain AVMs indicates that this new embolic material does not adversely affect subsequent microneurosurgical removal of the AVM, as it keeps the consistency of the nidal vessels elastic and formable and allows for dissection of the nidus from the surrounding brain tissue. The historically observed accompanying inflammatory reaction seems to be mainly limited intraluminally need intramurally and not to extend significantly into the perinidal brain parenchyma. So far, however, the reported morbidity and mortality of embolization of cerebral AVMs with Onyx is significantly higher than with the use of NBCA. It seems that this higher morbimortality rate is primarily attributed to a higher incidence of embolization-induced hemorrhage, followed by arterial ischemic complications. Technical complications with or without clinical consequences and linked to the use of Onyx or to the special microcatheters used for its delivery include local subarachnoid hemorrhage observed in the vicinity of the embolized AVM, perforation of feeding arteries, glued microcatheters within the vessel lumen due to significant

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A. Valavanis


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Interventional Neuroradiology 11: 9-12, 2005

reflux of Onyx into the feeding artery, escape of Onyx into the dominant draining vein and possibly expansion of the nidus due to injection of high volume of Onyx. Overall, these complications and morbimortality rates are certainly higher than those reported from centers with long experience in the use of NBCA for embolization of brain AVMs. Any newly developed and clinically introduced embolic material for use in the endovascular treatment of cerebral AVMs should fulfill certain key criteria, i.e. • it should be able to permanently occlude the intranidal vascular channels composing the shunting zone of the AVM. • it should be non-adhesive thus permitting long-lasting injections without the risk of gluing the microcatheter within the feeding arteries. • it should be able to penetrate into adjacent compartments in niduses with intercompartmental communications. • it should be non-toxic, neither to the vessel wall nor to the nervous tissue thus avoiding angionecrosis and damage of brain parenchyma. The intranidal behaviour of a polymerizing fluid embolic material such as NBCA or Onyx depends on several factors such as the position of the tip of the microcatheter (wedged of not wedged), the type of arteriovenous shunts composing the nidus and its compartments (plexiform, fistulous, or mixed), the presence of absence of intercompartmental communicating vascular channels, the nidal-venous junction (single or multiple draining veins), the size and shape of the proximal segment of the exiting nidal draining veins (large vs small veins), presence or absence of venous luminal stenoses with or without varix, presence or absence of intranidal vascular cavities (arterial flow-related aneurysms, posthemorrhagic pseudoaneurysms, venous intranidal ecstasias) and the intranidal flow conditions (high-, moderate- or low-flow). Depending on all these angioarchitectural and hemodynamic factors, different concentrations of the polymerizing embolic material , different injection modes, rates, volumes and pressures will be required in order to achieve a satisfactory intranidal distribution and deposition of the embolic material, without occlusion of distal segments of feeding arteries and without compromise of the nidal draining veins. Evidently, this requires meticulous analysis of the selective and superselective angiograms, precise and optimal positioning of the microcatheter tip and ad-hoc development of an individualized injection concept adapted to the uniquness of the angioarchitecture and hemodynamics of the case under treatment. At the end of this short editorial I take the liberty to make a few statements derived from my personal experience with treating patients with cerebral AVMs during the past 25 years:

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Editorial

A. Valavanis

Cerebral AVMs remain enigmatic neurovascular lesions in many aspects of their origin, natural history, clinical presentation, pathobiology and response to the various treatment modalities. • Each case of cerebral AVM is with regard to its angioarchitectonic and hemodynamic features as well as to the host-AVM relationship unique. Any decision to be taken and any treatment to be applied must respect this uniqueness and must be adapted to it. • There are no “easy” cerebral AVMs to treat and there are no “easy to use” embolic materials. • Acquisition of the necessary pertinent knowledge, training in respectful, gentle and precise neuroendovascular microcatheterization, development and maintenance of manual dexterity and skills, accumulation and application of experience obtained from both the observation of “masters” and from the personal work along with definition of the goal of the endovascular treatment prior and not during the procedure as well as the conviction that all brain areas are highly eloquent are the key elements guiding the practice of embolization of cerebral AVMs. I wish to thank all those who submitted their contributions to this special issue of the journal thus helping to compile a remarkable set of articles, which allow the readership to obtain a broad, updated and detailed information on the state of the art of endovascular interventional neuroradiological concepts, strategies, techniques and results on treatment of cerebral AVMs. •

Prof. Anton Valavanis Institute of Neuroradiology University Hospital of Zurich

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Interventional Neuroradiology 11: 13-29, 2005

Therapeutic Management of Cerebral Arteriovenous Malformations. Present Role of Interventional Neuroradiology F. VIÑUELA, G. DUCKWILER, R. JAHAN, Y. MURAYAMA Division of interventional Neuroradiology (DINR), UCLA School of Medicine and Medical Center; San Francisco, USA

Key words: AVMs, embolization, therapeutic neuroradiology

This chapter summarizes the authors’ experience in the endovascular therapy of cerebral arteriovenous malformations (AVMs). This clinical series includes 660 patients treated from 1980 to 2005. The first 148 patients were treated at University Hospital, in London, Ontario Canada, in association with Drs. Allan Fox, Dave Pelz, John Girvin and Charles Drake. The next 512 patients were treated at UCLA Medical Center, Los Angeles, California in association with Drs. Gary Duckwiler, Reza Jahan, Jacques Dion, Pierre Gobin, Neil Martin and John Frazee. Only patients treated with superselective endovascular/intraoperative catheterization and embolization of avm arterial feeders were included. Cerebral arteriovenous malformations treated by non-selective injection of beads in ICA or vertebral arteries were excluded. Modern neuroimaging modalities associated to the anatomical, topographic and functional evaluations of cerebral avms such as brain CT and CTA, MRI, MRA and functional MRI are all utilized at UCLA Medical Center. They have become essential in the therapeutic management of avms closely related to cerebral eloquent areas (figure 1). Patients Age and Sex The patients’age ranged between 4 and 83 years old, with an age average of 45.7 years old. Three hundred and fifty four patients were male (53.6%) and 306 were female (46.4%).

Patients Clinical Presentation (table I) Three hundred and eleven patients presented with an intracerebral hemorrhage (47.1%). Ninety two bleeds were predominantly subarachnoid (13.9%), 170 were parenchymal (25.8%) and 49 patients had a predominant intraventricular hemorrhage (7.4%). Two hundred and sixty one patients (39.5%) presented with seizures , 42 patients (6.5%) had severe headaches, 33 patients (5%)developed a progressive neurological syndrome and in 13 patients (1.9%) the avm was discovered incidentally. Size of AVMs (table II) One hundred and seventy-four AVMs were small (<3 cm in largest diameter) (26.3%), 248 were medium (3 to 6 cm in largest diameter) (37.5%), 214 were large (longest diameter >6 cm) (32.6%) and 24 were giant (3.6%), (26.3%). AVM Angioarchitecture by Superselective Angiography (table III) Diagnostic imaging modalities such as standard cerebral angiography, head CTA and MRA offer excellent overall information on avm size and location. Three-D rotational digital angiography is not as useful in cerebral avms as in cerenbral aneurysms. The exception is the avm supplied by anterior or posterior perforators. In these

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Therapeutic Management of Cerebral Arteriovenous Malformations. Present Role of Interventional Neuroradiology

F. Vi単uela

Figure 1 Functional MRI in a patient harboring a small left parietal avm. Specific paradigms were used to depict primary motor-sensory strips and their relationship to the avm nidus.

Table I Therapeutic Management of Brain Arteriovenous Malformations: Experience with 660 Patients

Clinical Presentation Hemorrhage

SAH

92 pts.

13.9%

Parenchemal

170 pts.

25.8%

Intraventricular

49 pts.

7.4%

261 pts.

39.5%

Progressive Neurological Syndrome

33 pts.

5%

Headaches

42 pts.

6.5%

Incidental

13 pts.

1.9%

Seizures

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Interventional Neuroradiology 11: 13-29, 2005

Table II Therapeutic Management of Brain Arteriovenous Malformations: Experience with 660 Patients

AVM Size • Small

174 pts.

26.3%

• Medium

248 pts.

37.5%

• Large

214 pts.

32.6%

• Giant

24 pts.

3.6%

Table III Therapeutic Management of Brain Arteriovenous Malformations: Experience with 660 Patients

AVM Topography • Cortical/Subcortical

Dominant

279 pts.

42.3%

N-Dominant

233 pts.

35.3%

• Cerebellum

48 pts.

7.4%

• Corpus Callosum

37 pts.

5.6%

• Basal Ganglia

27 pts.

4

• Incisura

17 pts.

2.6%

• Thalamus

19 pts.

2.8%

Table IV Therapeutic Management of Brain Arteriovenous Malformations: Experience with 660 Patients

Techniques of Embolization • Transfemoral

599 pts.

90.7%

• Intraoperative

24 pts.

3.6%

• Transfemoral + Intraoperative

8 pts.

1.3%

• Attempts

12 pts.

1.8%

• Functional Evaluation

17 pts.

2.6%

cases, the 3D rotational angiogram identifies the ostium of perforators better than the standard angiogram, facilitating their superselective catherization (figure 2). Superselective angiography of AVM arterial feeders continues to be the best diagnostic tool to depict anatomical data that influences the type and delivery of embolic agents. This anatomical data was collected from more than 1200 superselective angiograms performed immediately before delivery of embolic agents into the AVM nidus. Intranidal aneurysms were found in 109 patients (16.5%) (figure 3).

Intranidal arteriovenous fistulae were identified in 145 AVMs (21.9%) (figure 4). Stenosis of large AVM draining veins were observed in 102 cases (15.4%) and contribution from anterior or posterior arterial perforators was depicted in 93 AVMs (14%). AVM Topography (table IV) Five hundred and twelve AVMs (77.5%) had predominant cortical/subcortical locations. Two hundred and seventy nine (42.3%) involved the dominant and 233 AVM (35.3%) were located in non-dominant cerebral hemispheres.

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Therapeutic Management of Cerebral Arteriovenous Malformations. Present Role of Interventional Neuroradiology

F. ViĂąuela

A

B

Figure 2 3-D digital angiography and AVMs. A)- 3-D rotational digital angiogram shows distinct origin of lenticulostriate arteries. B)- 2D digital angiogram shows the same vascular anatomy though with less details. This difference in visualization of perforators in more complicated cases impinges upon the technical success or failure of their catheterization.

Forty eight (7.4%) AVMs involved the cerebellum, 37 (5.6%) were in the corpus callosum, 27(4%) were located in basal ganglia, 17 (2.6%) were in incisura and 19 (2.8%) involved the thalamus. Techniques of AVM Embolization The aim of the endovascular therapist is to occlude as much of the avm nidus with preservation of blood supply of the normal brain parenchyma. The authors success rate of endovascular complete AVM occlusion is relatively low (56/660 patients-8.5%) though 264/660 (â&#x20AC;&#x201C;43.3%) patients had a complete anatomical cure of the avm using a combination of embolization and surgery. These results are the reflection of a team approach that emphasizes to achieve a complete AVM cure with acceptable morbidy/mortality, in the shortest possible time. The exceptional quality of neurovascular surgery at UCLA allows this type of approach with excellent anatomical and clinical outcomes. Most patients were under general anesthesia throughout the endovascular embolization. In patients with AVMs located in brain eloquent areas or fed by arterial perforators (me-

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dial lenticulostriate, thalamo-perforators, anterior choroidal artery,etc) a functional amytal testing was performed with the patient awake , EEG monitoring and close neurological monitoring. The amytal testing consisted in a selective, rapid injection of 36 mg of amytal using a 3 cc syringe while the patient was performing a functional task (elevating controlateral arm or moving toes, counting or repeating a complex sentence, etc). This test could be repeated if a questionable result was observed). The injection of amytal was delivered into the arterial feeder approximately 4 cm proximal to the AVM nidus. The target of this functional test was to evaluate the brain parenchyma surrounding the AVM nidus and supplied by the arterial feeder before reaching the AVM nidus (arterial retrograde thrombosis after AVM embolization). The functional amytal testing was performed in 235 AVMs. (35.6%). A positive amytal testing was observed in 25 cases (10.6%). A negative test was seen in 215 patients (91.4%). Thirteen of those tests that were interpreted as negative were false negative (6.04%). The selective catheterization of arterial feed-


Mavs