Management Of Brain Arteriovenous Malformations Research Articles

Transarterial AVM embolization using Tsinghua grading system: Patient selection and complete obliteration

ObjectiveEndovascular embolization has an important role in the management of brain arteriovenous malformations (AVMs). A Tsinghua AVM grading system has been proposed for patient selection and complete obliteration. The authors sought to validate this system in an independent patient cohort and compare it to the Buffalo grading system. MethodsConsecutive 52 patients underwent endovascular AVM embolization between January 2019 and December 2021 according to Tsinghua AVM grading system. Each AVM was also graded using Buffalo grading system. Baseline clinical characteristics, complications, and AVM obliteration were compared between Tsinghua and Buffalo scales. ResultsComplete obliteration of AVM was obtained in 29 patients (55.8%). Three complications were encountered, one bleeding (1.9%) and 2 ischemic (3.8%), in 3(5.7%) patients who recovered completely at follow-up. The Tsinghua scale (p=0.017) was predictor of complete obliteration as well as Buffalo scale (p=0.002) on ROC curve analysis and their AUCs were not significantly different (p=0.672). The Tsinghua scale was also associated with the initial patient status (p=0.003) and injected Onyx volume (p=0.003) on linear regression test. Because of the low complication rate, neither the Tsinghua scale nor the Buffalo scale predicted complication risk related to AVM embolization. ConclusionsThe bleeding complication rate of 1.9% is within the range of rupture risk reported in the natural history of AVMs. In addition to predicting complete AVM obliteration as well as Buffalo scale, the Tsinghua scale can also predict the patients' status and the volume of Onyx avoid over injection. Key messagesThe Tsinghua grading system for endovascular AVM embolization will guide patient selection of AVM embolization.

Management of Brain Arteriovenous Malformations: A Review.

Brain arteriovenous malformations (bAVM) are vascular malformations of the brain affecting all ages. The optimum management strategy is essentially devoid of high-quality evidence and is highly nuanced and embedded in local customs.This study summarizes the frequently employed management strategies, drawing conclusions on the utility of each method of treatmentand delving into controversies surrounding them.A literature search on PubMed and Medline was done on January 3rd, 2022.11,767 articles were found, and abstracts were reviewed. Full-text reviewof 153 articles led to chapters from three books and 71 articles incorporated into a summative discussion. Spetzler-Ponce (S-P) Class A patients may be offered surgery if they are good surgical candidates and have a good number of high-quality years of life left. The exception is diffuse Spetzler-Martin (S-M) grade 2 in a patient older than 40 years: radiosurgery for unrupturedand embolization for ruptured. S-P Class B may be offered surgery if a compact nidusor if younger than 40 years. If diffuse or age greater than 40, radiosurgery may be preferred if the Pollock-Flickinger score is less than 2.5. For the remainder of S-P Class B, conservative management may be preferred. S-P Class C isgenerally not treated unless youngor those patients with poorly controlled seizures affecting their quality of life are willing to risk permanent neurological deficits. While the quality of studies is generally high, the level of evidence is concerning with only one randomized controlled trial (RCT). Most research output hails from high-income countries, i.e., perhaps not universally applicable to all settings owing to possible genetic, environmental, and resource differences. More research is needed: large volume studies in the pregnant population, validation of scoring systems in pediatric age groups,clinical trials focused on combination multi-staged treatment modalities, and studies originating from the developing world.

State of the Art in the Role of Endovascular Embolization in the Management of Brain Arteriovenous Malformations—A Systematic Review

As a significant cause of intracerebral hemorrhages, seizures, and neurological decline, brain arteriovenous malformations (bAVMs) are a rare group of complex vascular lesions with devastating implications for patients' quality of life. Although the concerted effort of the scientific community has improved our understanding of bAVM biology, the exact mechanism continues to be elucidated. Furthermore, to this day, due to the high heterogeneity of bAVMs as well as the lack of objective data brought by the lack of evaluative and comparative studies, there is no clear consensus on the treatment of this life-threatening and dynamic disease. As a consequence, patients often fall short of obtaining the optimal treatment. Endovascular embolization is an inherent part of multidisciplinary bAVM management that can be used in various clinical scenarios, each with different objectives. Well-trained neuro-interventional centers are proficient at curing bAVMs that are smaller than 3 cm; are located superficially in noneloquent areas; and have fewer, larger, and less tortuous feeding arteries. The transvenous approach is an emerging effective and safe technique that potentially offers a chance to cure previously untreatable bAVMs. This review provides the state of the art in all aspects of endovascular embolization in the management of bAVMs.

Transvenous embolization of hemorrhagic brain arteriovenous malformations: Case reports and literature review.

IntroductionTransvenous embolization (TVE) has been proven to be safe and feasible as an alternative management of brain arteriovenous malformations (AVMs). We presented four patients with a hemorrhagic brain AVM who underwent TVE and reviewed the relevant literature.MethodsFour patients underwent TVE of a hemorrhagic brain AVM in our center between July 2019 and July 2020. We retrospectively collected and analyzed the clinical and imaging data of these patients and those reported in previously published studies.ResultsFour patients with a hemorrhagic brain AVM were included. Nidus sizes ranged from 0.79 to 2.56 cm. Spetzler-Martin grade ranged from grade II to grade III. The AVM nidus was located in a deep brain region in three patients. One patient underwent TVE alone and three underwent combined transarterial and transvenous approaches. Digital subtraction angiography (DSA) demonstrated complete obliteration of the vascular malformation after embolization in all four patients. Three patients were independent [modified Rankin Scale (mRS) score ≤ 2] at discharge. All four patients were independent at the last follow-up. AVM obliteration was confirmed in all four patients at the last angiographic follow-up.ConclusionTransvenous embolization can be used as an alternative treatment for contemporary management of brain AVMs, appropriate patient selection is essential to achieve a good clinical outcome.

Understanding burden of proof and equipoise in the design of pragmatic clinical trials: An example from a trial on brain arteriovenous malformations

Background and purposeThe burden of proof principle is rarely discussed and poorly understood, but central to the proper design of pragmatic clinical trials. A better understanding of the principle could play an important role in the re-introduction of scientific methods within practice and in revising fundamental problems with the current research-care separation. MethodsWe analyze the design of the ARUBA trial on the management of unruptured brain arteriovenous malformations. We also review how the concept of clinical equipoise was introduced to address a misconceived problem of research ethics. ResultsThe ARUBA trial hypothesis in favour of conservative management of brain arteriovenous malformations failed to take into account the fact that the burden of proof was on surgery, endovascular treatment or radiation therapy. Thus, results remained inconclusive and other trials are needed. The equipoise notion fails to take into account that the burden of proof is on unvalidated medical or surgical interventions, if we want to provide outcome-based medical care that patients can trust. ConclusionThe burden of proof principle is essential to properly design pragmatic trials. This principle also explains why in certain circumstances optimal care is a randomized care trial.

Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas.

Aim: The aim of this guideline is to present current and comprehensive recommendations for the management of brain arteriovenous malformations (bAVMs) located in eloquent areas.Methods: An extended literature search on MEDLINE was performed between Jan 1970 and May 2020. Eloquence-related literature was further screened and interpreted in different subcategories of this guideline. The writing group discussed narrative text and recommendations through group meetings and online video conferences. Recommendations followed the Applying Classification of Recommendations and Level of Evidence proposed by the American Heart Association/American Stroke Association. Prerelease review of the draft guideline was performed by four expert peer reviewers and by the members of Chinese Stroke Association.Results: In total, 809 out of 2,493 publications were identified to be related to eloquent structure or neurological functions of bAVMs. Three-hundred and forty-one publications were comprehensively interpreted and cited by this guideline. Evidence-based guidelines were presented for the clinical evaluation and treatment of bAVMs with eloquence involved. Topics focused on neuroanatomy of activated eloquent structure, functional neuroimaging, neurological assessment, indication, and recommendations of different therapeutic managements. Fifty-nine recommendations were summarized, including 20 in Class I, 30 in Class IIa, 9 in Class IIb, and 2 in Class III.Conclusions: The management of eloquent bAVMs remains challenging. With the evolutionary understanding of eloquent areas, the guideline highlights the assessment of eloquent bAVMs, and a strategy for decision-making in the management of eloquent bAVMs.

Expert Consensus on the Management of Brain Arteriovenous Malformations.

Brain arteriovenous malformations (bAVMs) are complex, heterogeneous, and uncommon intracranial lesions. They can be treated by one or a combination of the following treatment modalities, namely embolization, radiosurgery, or microsurgical resection. In Spetzler-Martin Grade 4 and 5 arteriovenous malformations (AVMs), conservative management may be the best option. A group of experts in the management of AVMs of different disciplines gathered in January 2019 in Hanoi to compile the “Expert Consensus on the Management of Brain Arteriovenous Malformations”.

In Reply: Risk of First Hemorrhage of Brain Arteriovenous Malformations During Pregnancy: A Systematic Review of the Literature.

Background Recommendations on the management of brain arteriovenous malformations (bAVM) with respect to pregnancy are based upon conflicting literature. Objective To systematically review the reported risk and annualized rate of first intracranial hemorrhage (ICH) from bAVM during pregnancy and puerperium. Methods MEDLINE, EMBASE, and Scopus databases were searched for relevant articles in English published before April 2018. Studies providing a quantitative risk of ICH in bAVM during pregnancy were eligible. Results From 7 initially eligible studies, 3 studies met the criteria for providing quantitative risk of first ICH bAVM during pregnancy. Data from 47 bAVM ICH during pregnancy across 4 cohorts were extracted for analysis. Due to differences in methodology and definitions of exposure period, it was not appropriate to combine the cases. The annualized risk of first ICH during pregnancy for these 4 cohorts was 3.0% (95% confidence interval [CI]: 1.7-5.2%); 3.5% (95% CI: 2.4-4.5%); 8.6% (95% CI: 1.8-25%); and 30% (95% CI: 18-49%). Only the last result from the last cohort could be considered significantly increased in comparison with the nonpregnant period (relative rate 6.8, 95% CI: 3.6-13). The limited number of eligible studies and variability in results highlighted the need for enhanced rigor of future research. Conclusion There is no conclusive evidence of an increased risk of first hemorrhage during pregnancy from bAVM. Because advice to women with bAVM may influence the management of pregnancy or bAVM with significant consequences, we believe that a retrospective multicenter, case crossover study is urgently required.

Risk of First Hemorrhage of Brain Arteriovenous Malformations During Pregnancy: A Systematic Review of the Literature.

Recommendations on the management of brain arteriovenous malformations (bAVM) with respect to pregnancy are based upon conflicting literature. To systematically review the reported risk and annualized rate of first intracranial hemorrhage (ICH) from bAVM during pregnancy and puerperium. MEDLINE, EMBASE, and Scopus databases were searched for relevant articles in English published before April 2018. Studies providing a quantitative risk of ICH in bAVM during pregnancy were eligible. From 7 initially eligible studies, 3 studies met the criteria for providing quantitative risk of first ICH bAVM during pregnancy. Data from 47 bAVM ICH during pregnancy across 4 cohorts were extracted for analysis. Due to differences in methodology and definitions of exposure period, it was not appropriate to combine the cases. The annualized risk of first ICH during pregnancy for these 4 cohorts was 3.0% (95% confidence interval [CI]: 1.7-5.2%); 3.5% (95% CI: 2.4-4.5%); 8.6% (95% CI: 1.8-25%); and 30% (95% CI: 18-49%). Only the last result from the last cohort could be considered significantly increased in comparison with the nonpregnant period (relative rate 6.8, 95% CI: 3.6-13). The limited number of eligible studies and variability in results highlighted the need for enhanced rigor of future research. There is no conclusive evidence of an increased risk of first hemorrhage during pregnancy from bAVM. Because advice to women with bAVM may influence the management of pregnancy or bAVM with significant consequences, we believe that a retrospective multicenter, case crossover study is urgently required.

Short Term Effectiveness of Gamma Knife Radiosurgery in the Management of Brain Arteriovenous Malformation.

AIM:To evaluate the short-term effectiveness of Gamma knife radiosurgery as a modality of treatment of brain arteriovenous malformation.METHODS:Sixty-three patients with arteriovenous brain malformations underwent Gamma knife radiosurgery included in this prospective study between April 2017 and September 2018 with clinical and radiological with MRI follow up was done at three months and six months post-Gamma knife radiosurgery. By the end of the 12th-month post-Gamma knife radiosurgery, the patients were re-evaluated using digital subtraction angiography co-registered with M.R.I. During the 12 months follow up, CT scan or MRI was done at any time if any one of the patients' condition deteriorated or developed signs and symptoms of complications. The mean volume of the arteriovenous malformations treated was 26.0 ± 5 cm3 (range 12.5–39.5 cm3) in The Neurosciences Hospital, Baghdad/Iraq.RESULTS:By the end of the 12th month of follow up, the overall obliteration of the arteriovenous malformations was seen in six patients only (9.5%), while shrinkage was noticed in 57 patients (90.5%). Improvement or clinical stability was found in 24 out of 39 patients (61.5%) presented with epilepsy as a chief complaint before Gamma knife radiosurgery and 21 out of 24 patients (87.0%) complained of a headache before Gamma knife radiosurgery. Post-Gamma knife radiosurgery bleeding was found in only three patients (5.0%).CONCLUSION:Even with the short term follow up, Gamma knife radiosurgery has an excellent clinical outcome in most patients with arteriovenous brain malformations. The clinical symptoms like headache and seizure were either diminished or controlled with the same medical treatment dose before Gamma knife radiosurgery. Long term clinical and radiological follow up is recommended.

A Retrospective Cohort Analysis of Hemorrhagic Arteriovenous Malformations Treated with Combined Endovascular Embolization and Gamma Knife Stereotactic Radiosurgery

The management of brain arteriovenous malformations (AVMs) remains a controversial topic. Given the relatively low incidence, high heterogeneity, and high morbidity and mortality of these lesions, consensus on treatment strategies is an issue of concern to organized neurosurgery. The present retrospective analysis examined and quantified the outcomes of patients with an initial presentation of intracranial hemorrhage from a Spetzler-Martin grade III or IV AVM, later ruled out as surgical candidates. A total of 16 patients (5 females; 11 males) had presented with symptomatic hemorrhage confirmed by non-contrast-enhanced computed tomography and were deemed to not be surgical candidates owing to AVM location and/or architecture. The patients underwent combined endovascular embolization and gamma knife stereotactic radiosurgery (SRS). The modified Rankin scale was used to measure the clinical outcomes, comparing the scores at presentation, gamma knife treatment, and the last known follow-up examination. A radiographic evaluation was used to determine the level of AVM nidus involution after the procedure. The present study identified 16 patients with ruptured high-grade AVMs of high surgical risk. All the patients had undergone immediate embolization with delayed SRS for treatment of the hemorrhage and nidus of the AVM. A statistically significant proportion of patients showed marked improvement in the modified Rankin scale scores. No subsequent repeat hemorrhage or any associated complications after embolization occurred in any patient. These findings warrant consideration of endovascular embolization with adjuvant SRS as a powerful treatment option for cases with high surgical morbidity due to AVM characteristics.

Stereotactic Radiosurgery for Brain Arteriovenous Malformations

Stereotactic radiosurgery is an established treatment modality in the management of brain arteriovenous malformations (AVMs). Technological advances in radiation delivery systems associated with improvements in neuroimaging have recently changed radiosurgery indications and results. Besides this advances, and the association with microsurgery and embolization, the management of these benign lesions are still controversial. AVMs in eloquent areas and those with large volumes remain a challenge for all treatment modalities. This article discusses the modern approach of radiosurgery for brain AVMs including new options such as combined approaches and the use of hipofractionated stereotactic radiation for large and high flow lesions.

The Treatment of Brain AVMs Study (TOBAS): an all-inclusive framework to integrate clinical care and research

OBJECTIVE The management of brain arteriovenous malformations (bAVMs) remains controversial. The Treatment of Brain AVMs Study (TOBAS) was designed to manage patients with bAVMs within a clinical research framework. The objective of this study was to study trial feasibility, recruitment rates, patient allocation to the various management groups, and compliance with treatment allocation. METHODS TOBAS combines two randomized care trials (RCTs) and a registry. Designed to be all-inclusive, the study offers randomized allocation of interventional versus conservative management to patients eligible for both options (first RCT), a second RCT testing the role of preembolization as an adjunct to surgery or radiotherapy, and a registry of patients managed using clinical judgment alone. The primary outcome of the first RCT is death from any cause or disabling stroke (modified Rankin Scale score > 2) at 10 years. A pilot phase was initiated at one center to test study feasibility, record the number and characteristics of patients enrolled in the RCTs, and estimate the frequency of crossovers. RESULTS All patients discussed at the multidisciplinary bAVM committee between June 2014 and June 2016 (n = 107) were recruited into the study; 46 in the randomized trials (23 in the first RCT with 21 unruptured bAVMs, 40 in the second RCT with 17 unruptured bAVMs, and 17 in both RCTs), and 61 patients in the registry. Three patients crossed over from surgery to observation (first RCT). CONCLUSIONS Clinical research was successfully integrated with normal practice using TOBAS. Recruitment rates in a single center are encouraging. Whether the trial will provide meaningful results depends on the recruitment of a sufficient number of participating centers. Clinical trial registration no.: NCT02098252 (clinicaltrials.gov).

Introduction to the supratentorial cerebral arteriovenous malformation video supplement.

It is with great pleasure that we present this Neurosurgical Focus video supplement on supratentorial cerebral arteriovenous malformations (AVMs). We were privileged to view a remarkable number of outstanding videos demonstrating current state-of-the-art management of brain AVMs using endovascular and microsurgical modalities. Careful and critical review was required to narrow down the submitted videos to a workable volume for this supplement, which reflects the excellent work being done at multiple centers with these lesions. This issue consists of videos that represent modern microsurgical and neuroendovascular techniques for the treatment of supratentorial cerebral AVMs. The videos demonstrate cutting-edge therapies as well as standard ones, which will be valuable to both novice and expert neurointerventionists and neurosurgeons. We are honored to be involved with this project and proud of its content and expert authors. We believe you will enjoy the video content of this supplement and hope that it will raise the collective expertise of our community of AVM surgeons.

Management of Brain Arteriovenous Malformations: A Scientific Statement for Healthcare Professionals From the American Heart Association/American Stroke Association.

The aim of this statement is to review the current data and to make suggestions for the diagnosis and management of both ruptured and unruptured brain arteriovenous malformations. The writing group met in person and by teleconference to establish search terms and to discuss narrative text and suggestions. Authors performed their own literature searches of PubMed, Medline, or Embase, specific to their allocated section, through the end of January 2015. Prerelease review of the draft statement was performed by expert peer reviewers and by the members of the Stroke Council Scientific Oversight Committee and Stroke Council Leadership Committee. The focus of the scientific statement was subdivided into epidemiology; diagnosis; natural history; treatment, including the roles of surgery, stereotactic radiosurgery, and embolization; and management of ruptured and unruptured brain arteriovenous malformations. Areas requiring more evidence were identified. Brain arteriovenous malformations are a relatively uncommon but important cause of hemorrhagic stroke, especially in young adults. This statement describes the current knowledge of the natural history and treatment of patients with ruptured and unruptured brain arteriovenous malformations, suggestions for management, and implications for future research.

The Treatment of Brain Arteriovenous Malformation Study (TOBAS): A preliminary inter- and intra-rater agreement study on patient management

ObjectThe best management of brain arteriovenous malformation (bAVM) patients remains unknown. Randomized allocation may be more readily accepted when there is uncertainty and disagreement regarding the management of potential participants. In planning for a trial, we aimed to assess variability and agreement among physicians managing bAVM patients. MethodsA portfolio composed of 35 patients was sent to 47 clinicians of various specialties managing bAVM patients. For each patient, physicians were asked their best management decision (surgery/embolization/radiosurgery/conservative), their confidence level, and whether they would include the patient in a randomized trial comparing conservative and curative management. Seven physicians, who had access to all images of each patient, independently responded twice, to assess inter and intra-rater agreement using kappa statistics. ResultsThe inter-rater agreement (30 raters, including 16 neuroradiologists) for best management decision was only “fair” (κ [95%CI]=0.210[0.157; 0.295]). Agreement remained below ‘substantial’ (κ<.6) between physicians of the same specialty, and when no distinctions were made between various treatments (when responses were dichotomized as conservative versus curative). With access to all images the inter-rater agreement remained fair. The intra-rater agreement reached “substantial” only for the dichotomized decisions. Responding clinicians were willing to include 54.4% of patients (mainly unruptured bAVMs) in a randomized trial. ConclusionThere is a lack of agreement among clinicians involved in the management of bAVM patients. In this study a substantial proportion of clinicians were willing to offer randomized allocation of management options to a substantial number of patients.

Comparative surgical outcome associated with the management of brain arteriovenous malformation in a regional neurosurgical centre

Objectives: Microsurgical resection of brain arteriovenous malformation (AVMs) is challenging, however, expert surgical series from large volume centres, have reported over 95% occlusion rates with 2 to 8% risk of morbidity & mortality. Data from a regional neurosurgical unit was analysed and compared with published series for the purposes of quality control. We also compared our surgical result with other treatment modalities from the whole AVM cohort managed over the same study period.Design: Retrospective analysis of a locally held AVM database.Subjects: Of the 141 AVM patients, 54 (35M, 19F, age range 9–68 years) underwent microsurgical removal of AVM by the senior author, from 2006 to 2012. 27 (19%), 18 (13%), 20 (14%), 22 (16%) had endovascular therapy only, radiosurgery only, combination therapy (endovascular and radiosurgery) and conservative management, respectively.Methods: Case notes were reviewed to determine clinical and radiological outcomes. Statistical analysis performed using SPSS with p < 0.05 defined as statistical significance.Results: In the surgical series, the Spetzler–Martin (SM) grade distribution was as follows: 17 grade I (32%), 31 grade II (57%), and 6 grade III (11%). 31 patients (57%) presented with intracranial haemorrhage, 12 patients (22%) with seizures. Of the 54 patients, 51 (94%) had angiographically confirmed obliteration of their AVM. Median follow-up for the entire cohort was 7 years. 83% of surgical patients have mRS 0–1, compared to 78%, 67%, 45%, 18% of patients managed by endovascular therapy, radiosurgery, combination therapy, conservative surveillance, respectively (p < 0.0001). However, the groups were not comparable in terms of SM grade or clinical presentation and the numbers in each group were relatively small. Seizure presentations were encountered in 23% (32/141) of the overall patients, and all the surviving patients were on anticonvulsants, except in the surgical arm, 7/12 (58%) patients were off their antiepileptic medications at last follow-up.Conclusions: The results demonstrate a 94% surgical obliteration rate and 11% long-term neurological deficits for brain AVM patients managed surgically and were comparable to expert series. Achieving acceptable results is possible in lower volume settings, however, patient selection is important and the role of an experienced neurovascular team cannot be overstated.

P-033 ethanol sclerotherapy of feeding artery and nidal aneurysms in ruptured cerebral arteriovenous malformations: Abstract P-033 Table 1

Background Embolic agents for embolization of cerebral arteriovenous malformations (AVMs) currently include n-BCA, Onyx, particles, and detachable coils. Ethanol sclerotherapy is seldom used in the treatment of cerebral AVMs due to safety concerns. 1,2 In some circumstances, however, such as when limited reflux of an embolic agent is permissible, the use of ethanol may be preferable. In this retrospective case series, we report on patients with brain AVMs presenting with acute hemorrhage at our institution in whom ethanol was used to successfully treat a feeding artery aneurysms or intranidal aneurysms. Methods A keyword search of our neurointerventional database identified 10 patients with cerebral AVM feeding artery aneurysms or intranidal aneurysms treated using ethanol sclerotherapy between 2005 and 2014. Neuroimaging, angiograms, operative reports and electronic medical records were reviewed. Results 13 feeding artery or intranidal aneurysms were identified in 10 patients, of which 12 were treated with intraarterial ethanol sclerotherapy (Table 1). One of the 13 aneurysms was not treated due to risk of non-target embolization of calcarine artery branches. All patients presented with acute intracranial hemorrhage. Dehydrated ethanol 60–80% (70% ethanol was used in 7 of the 10 patients) was delivered slowly under roadmap-mask guidance directly into the artery supplying the aneurysm. Post-therapy angiography to assess for aneurysm occlusion was performed 10–20 min after ethanol injection. Volume of ethanol injected ranged from 2–22 cc (median 3.75 cc) (Table 1). Complete occlusion of the aneurysm was seen in 11/12 treated aneurysms (92%) (Figure 1). Follow-up was available in 9/10 patients (mean follow-up was 1.3 years). None required more than one treatment session and there were no recurrences. A complication was encountered in one patient, who developed hemiparesis and aphasia due to non-target embolization of posterolateral choroidal artery branches to normal brain. No deaths were attributed to ethanol sclerotherapy. Conclusion In a subset of ruptured cerebral AVMs in which other embolic agents cannot be safely used, ethanol sclerotherapy of feeding artery or nidal aneurysms can be performed with a high degree of technical success and a low rate of permanent neurologic complication. References Yakes WF, Krauth L, Ecklund J, et al . Ethanol endovascular management of brain arteriovenous malformations: initial results. Neurosurgery 1997; 40 (6):1145–52; discussion 52–4 Wong GA, Armstrong DC, Robertson JM. Cardiovascular collapse during ethanol sclerotherapy in a pediatric patient. Paediatric Anaesthesia 2006;16(3):343–6 Disclosures F. Settecase: None. M. Amans: None. A. Nicholson: None. S. Hetts: None. D. Cooke: None. C. Dowd: None. R. Higashida: None. V. Halbach: None.

A Neurosurgical Call to Arms: Lessons from ARUBA, Mr. Clean, and the Hydrocephalus Clinical Research Network

Neurosurgeons have traditionally been at the forefront of investigations into clinical, translational, and basic science research to improve the quality of neurologic care. The pioneering work of Drs. Kassell and Gerk in the early versus late treatment of ruptured cerebral aneurysms (11) stands as a testament to our specialty’s long and illustrious history of critical examination of the problems of the time. However, the publication of certain randomized controlled trials (RCTs) has left the field in a more reactive posture of late. The past 12 months have provided neurosurgeons with the results of two large RCTs, ARUBA (14) and Mr. Clean (3), with the potential for diametrically different results on the field of neurosurgery. These trials demonstrated how quickly the care of neurosurgical patients can be impacted, for better or worse, in the modern age (Table 1). Although the goal of a prospective RCT is one to which we should all aspire (2), it can be difficult in many instances to ethically conduct the research “gold standard” in the face of previous large, well-conducted, experiential studies. Furthermore, the variability of disease within the central nervous system has also made some RCTs difficult to design and has produced results that have been subject to vociferous debate within the medical community. ARUBA, an RCT of medical management of brain arteriovenous malformations (bAVMs) versus surgical intervention, concluded that medical management alone was superior to intervention for the preventionofdeathorstroke(14).Theseresultshavebeentrumpeted inthemediaasthenewstandardofcareforpatientswithbAVMs.The widespreaddisseminationofthisstudymaylimitapatient’sabilityto consult with neurosurgeons, the subject matter experts on this disorder, as referring providers discount the role of any surgical intervention for these patients. Significant criticism of ARUBA’s design and execution question the validity and generalizability of the results from this trial (1, 21), but as the only National Institutes of Healthefunded RCT on bAVMs, this study’s impact may potentially carry more influence than any well-designed, new or historical, retrospective surgical series (19). Given this significant, ongoing controversy, it is evident that the final word on the best treatment for patients with bAVMs is yet to be spoken. Mr. Clean, an RCT comparing the standard-of-care medical management with or without intra-arterial treatment for largevessel anterior circulation strokes, concluded that intra-arterial treatment was superior to medical management alone (3). These findings have been supported with the reporting of additional RCTs of intra-arterial stroke treatments (5, 10). These additional studies were terminated after midterm analyses favored the intraarterial treatment arm (5, 10). In contrast to the findings from ARUBA, these results have been accepted with little to no criticism because of their well thought-out design and execution. These two examples stand in stark contrast to one another and serve to illustrate how RCTs of neurosurgical diseases performed by specialists outside of neurosurgery can significantly impact our field. As in most aspects of life, the “devil” is often found in the details of these trials. Study design and execution are critical to the validity and acceptance of any results. But regardless of the quality

The Diagnosis and Management of Brain Arteriovenous Malformations in a Single Regional Center

Cerebral arteriovenous malformations are vascular abnormalities in which arteriovenous shunting occurs through an abnormal vascular network (nidus) in the parenchyma. These lesions typically present by the third decade of life with cerebral bleeding, seizures, headache, or neurologic deficits; however, they are sometimes found incidentally. A retrospective analysis of intracranial AVMs referred to a single regional center, over a 7-year period, was performed to review the clinical presentation, pathologic features and management outcomes from January 2005 to December 2012. We identified 142 patients (56% female, age range 4-69 years). Emergency referrals accounted for 87% of the cohort with the most frequent presentation being headache and/or hemorrhage. More than half (52%) of the cases were observed to have a neurologic deficit on examination. The modal Spetzler-Martin Grade was 3 with 76% of lesions located in areas of eloquent brain and 57% of cases in the dominant hemisphere. Half of the cases had multiple feeder vessels, and 29% were associated with aneurysms. The nidus was obliterated in 91% of cases actively managed. Two thirds of patients were successfully treated with a single modality, the most common being embolization. Only 8% of cases were managed conservatively. Additionally, 93% of aneurysms identified were treated successfully. The complication rate was 7% with 2% of reported infection. The burden of AVM management is significantly enhanced by the number of emergency referrals. Interestingly, complication rates are higher in the unruptured cohort. Surgical management is the most effective modality, but it carries the highest complication rate. This accompanied by the challenges of AVM anatomy and associated pathology argue for expert service provision in a single center.