[Expert consensus on multidisciplinary diagnosis and treatment of brain arteriovenous malformation].

Brain arteriovenous malformation (BAVM) is a cerebral vasculature disorder caused by gene mutation. Current available treatment measures include surgical resection, interventional embolization and stereotactic radiosurgery. The three therapeutic methods have their own advantages for different vascular structures.However, due to the complex vascular architecture of the lesion and its close anatomical relationship with brain tissue, any single treatment can not safely and effectively treat all BAVM cases. Therefore, in order to better regulate and guide the clinical diagnosis and treatment of BAVM patients in China, the National Medical School for Neurological Diseases, the Professional Committee of Neurointervention of the Chinese Medical Doctor Association and the radio-neurosurgery Expert Committee of the World Chinese Neurosurgeons Association jointly discussed and formulated this expert consensus. After in-depth analysis of the evidence of evidence-based medicine at home and abroad, the expert group combined with the specific situation of China, and gave 33 recommendations on specific clinical diagnosis and treatment issues such as predictive factors of cerebral arteriovenous malformation hemorrhage, clinical risks during pregnancy, imaging diagnosis measures, and clinical treatment strategies, in order to provide guidance for the diagnosis and treatment of BAVM nationwide.

Hemangioblastoma and arteriovenous malformation in the same patient: a not random association or two isolated entities? Systematic review starting from a unique case.

BACKGROUND: The association between intracranial hemangioblastomas and arteriovenous malformations has been documented in very few cases in literature since 1965 and might present in three modalities: "intermixed, adjacent and separated (spatially and temporally)". Often, the pattern of presentation is "intermixed". According to our systematic review, we propose an adjustment of the previous classification, specifically for these entities. We describe the first case of a truly "spatially separated" association between these two lesions. METHODS: Our study encompassed all adult patients diagnosed with both intracranial hemangioblastoma and AVM who were evaluated in the last 20-year period, from 2003 to 2023 at Helsinki University Hospital. Cases of this coexistence were retrospectively identified and collected from clinical records. For the systematic review, studies reporting the coexistence of hemangioblastoma and AVM in adult patients (>18 years old) were selected. Given the rarity of this pattern, case reports were also included. RESULTS: The combined analysis of our systematic review and institutional retrospective study revealed a total of only seven identified cases. We applied the classification of neoplasms and AVM by Yano, modifying and adapting it into our screened patient series. We systematically reclassified "adjacent" and genuinely "spatially separated" patterns based on the vascular axis supplying both lesions. CONCLUSIONS: Hemangioblastomas and AVMs rarely coexist in the same patient. Our study reports the first instance of a truly "spatially separated" sporadic association between these vascular lesions. The rarity of such coexistence underscores the need for a nuanced and systematic classification to guide the management of these infrequent cases.

Case Study of a Complex Neurovascular Disorder: Choroidal Arteriovenous Malformation.

This study conducts an in-depth analysis of the management of a complex arteriovenous malformation (AVM) in a 44-year-old individual, who initially manifested with acute left hemiparesis and progressively declined into a comatose state. Diagnostic neuroimaging identified a substantial right fronto-temporal intraparenchymal hematoma via a CT scan. Cerebral angiography further elucidated a choroidal AVM originating from the anterior choroidal artery, accompanied by intranidal aneurysms. The elected treatment strategy was the surgical excision of the AVM. The procedure achieved complete removal of the intracranial AVM, situated in a neurologically sensitive region, leading to notable neurological recovery. This study thoroughly explores and critically evaluates a wide spectrum of treatment approaches for intracranial arteriovenous malformations, including novel endovascular therapies. Despite extensive discourse on AVM in contemporary literature, this report is among the few documenting the treatment of a choroidal AVM via a microsurgical technique, and highlights various therapeutic options.

Peripheral macrophages in the development and progression of structural cerebrovascular pathologies.

The human cerebrovascular system is responsible for maintaining neural function through oxygenation, nutrient supply, filtration of toxins, and additional specialized tasks. While the cerebrovascular system has resilience imparted by elaborate redundant collateral circulation from supportive tertiary structures, it is not infallible, and is susceptible to developing structural vascular abnormalities. The causes of this class of structural cerebrovascular diseases can be broadly categorized as 1) intrinsic developmental diseases resulting from genetic or other underlying aberrations (arteriovenous malformations and cavernous malformations) or 2) extrinsic acquired diseases that cause compensatory mechanisms to drive vascular remodeling (aneurysms and arteriovenous fistulae). Cerebrovascular diseases of both types pose significant risks to patients, in some cases leading to death or disability. The drivers of such diseases are extensive, yet inflammation is intimately tied to all of their progressions. Central to this inflammatory hypothesis is the role of peripheral macrophages; targeting this critical cell type may lead to diagnostic and therapeutic advancement in this area. Here, we comprehensively review the role that peripheral macrophages play in cerebrovascular pathogenesis, provide a schema through which macrophage behavior can be understood in cerebrovascular pathologies, and describe emerging diagnostic and therapeutic avenues in this area.

Early experience of thalidomide therapy for high-grade peripheral and facial arteriovenous malformations.

BACKGROUND: Arteriovenous malformations (AVMs) are developmental defects in the vascular system with abnormal connections between arteries and veins. A minority of AVMs are characterized by aggressive growth and continue to proliferate despite maximal surgical and interventional therapy. We report our outcomes with the use of thalidomide as the only UK specialist center adopting this novel approach for the management of AVMs refractory to conventional therapy. METHODS: This was a retrospective case series which included only complex and proliferative AVM lesions (Schobinger grade III and IV). All patients prescribed thalidomide on a compassionate basis between September 2006 and August 2022 after attempts at embolosclerotherapy without satisfactory response were reviewed. RESULTS: Eleven patients were included in our study. The median total duration of thalidomide use was 10 months. Two thirds of patients with pain (six of nine) reported an improvement, three quarters reported a reduction in swelling (six of eight) and all who presented with bleeding reported improvement in overall volume or frequency (four of four). Over the study period, 45% achieved a non-proliferative state with no further target vessel demonstrable on angiography. Mild, tolerable side effects such as fatigue were common (73%). There was only one major adverse reaction (neutropenia) necessitating cessation of therapy. CONCLUSIONS: We can conclude that thalidomide is able to reduce the symptom burden for patients with complex and proliferative AVMs that were refractory to established treatment modalities. Adverse effects are common, but the benefit achieved from taking thalidomide in otherwise treatment resistant cases outweighs the risks, most of which are manageable.

Risk for Brain Arteriovenous Malformation Rupture During Pregnancy and Puerperium.

BACKGROUND: The hemorrhage risk of unruptured and untreated cerebral arteriovenous malformations (AVMs) has been shown to be higher for female patients than male patients in their child bearing ages. Although it has been neurosurgical practice to advise female patients in their childbearing ages to postpone pregnancy until proven AVM obliteration, there is no literature consensus regarding this potential hemorrhage risk increase. OBJECTIVE: To accurately quantify the risk increase for AVM hemorrhage during pregnancy. METHODS: This study is based on data from previous publications, consisting of known age at the first AVM hemorrhage in 3425 patients. The risk increase during pregnancy could be calculated from the difference in age distribution for the first AVM hemorrhage between male patients and female patients, taking the average pregnancy time per female into account. A comparison was also made with data for all hospital discharges (13 751) in Germany 2008 to 2018 with the diagnosis brain AVM. RESULTS: The average pregnancy and puerperium time was 1.54 years per female in the patient population, which was used to determine the annual AVM hemorrhage risk during pregnancy to be around 9%. The increased risk during pregnancy was further evidenced by analysis of a subgroup of 105 female patients, for which pregnancy status at the time of hemorrhage was known. CONCLUSION: The quantified annual risk for AVM hemorrhage during pregnancy is about 3 times higher than that of male patients at corresponding age. This provides an important basis for advising female patients with patent AVMs about the increased risk for hemorrhage that a pregnancy would entail.

The usefulness of three-dimensional fusion imaging of spinal arteriovenous malformation by a workstation connected to angiography systems.

Digital subtraction angiography (DSA) is the most useful technique for diagnosing spinal arteriovenous malformations (AVM). In recent years, with the improvement of imaging capabilities, the usefulness of three-dimensional (3D) imaging by fusing various modalities has been recognized. The use of 3D fusion imaging with a workstation connected to an angiography system has been reported in many cases of intracranial disease, but less frequently for spinal AVM. In this article, we describe two illustrative cases of spinal AVM in which 3D fusion imaging was useful for treatment. Although 3D fusion images using the system have the disadvantage that only a maximum of two images can be fused, it provides spinal surgeons with useful information for preoperative evaluation in a small amount of time.

A Rare Triploid Involving the Coexistence of Glioblastoma Multiforme, Arteriovenous Malformation and Intracranial Aneurysm: Illustrative Case and Literature Review.

The coexistence of glioblastoma multiforme (GBM) and arteriovenous malformation (AVM) is rarely reported in the literature. According to the present literature, these GBM or glioma-related vascular malformations may present simultaneously in distinct regions of the brain or occur in the same area but at different times. So far, these distinct hypervascular glioblastomas have been described but are not classified as a separate pathological entities. Considering their heterogeneity and complexity, all the above mentioned cases remain challenging in diagnosis and therapeutic modality. Likewise, there is a paucity of data surrounding the simultaneous presentation of GBM with intracranial aneurysms. In the literature, the independent concurrence of these three intracranial lesions has never been reported. In this article, we present a case who suffered from intermittent headaches and dizziness initially and further radiographic examination revealed an internal carotid artery (ICA) aneurysm that occurred in the patient with coexisting GBM and AVM. Surgical intervention for tumor and AVM removal was performed smoothly. This patient underwent endovascular coiling for the ICA aneurysm 4 months postoperatively. In addition, we also review the current literature relating to this rare combination of medical conditions.

Sphenoidal meningoencephalocele associated with CSF fistula and arteriovenous malformation Spetzler-Martin V: A case report.

Cerebral Arteriovenous malformations (AVMs) are presumed congenital anomalies of the blood vessels, which can increase intracranial pressure by uncertain mechanisms. We report the rare case of a 55-year-old male patient who complained about CSF rhinorrhea. Persisting CSF leakage prompted CT, which evidenced a bone defect in the right middle cranial fossa with protruding brain tissue. The diagnosis of a sphenoidal meningoencephalocele was made. Neuroimaging evidenced an AVM Spetzler Martin V. The lesion was targeted via an endonasal approach with resection of the herniated brain tissue and closure of the bony and dural defects. The postoperative course was uneventful without recurrence of the CSF fistula. Documentation of these cases is essential to come up with standardized therapeutical protocols and follow-up. Nevertheless, conservative management of the AVM and surgical repair of the bone defects is an appropriate approach in the first instance, depending on the morphology and characterization of the AVM.

Clinical Outcome and Quality of Life of Multimodal Treatment of Extracranial Arteriovenous Malformations: The APOLLON Study Protocol.

PURPOSE: Arteriovenous malformations (AVMs) as rare diseases are diagnostically and therapeutically challenging. Due to the limited evidence regarding treatment outcome, prospective data are needed on how different treatment regimens affect outcome. The aims of this prospective trial are to determine effectiveness, safety, and clinical outcome of multimodal treatment in patients with extracranial AVMs. MATERIALS AND METHODS: After clinical and magnetic resonance imaging (MRI)-based diagnosis and informed consent, 146 patients (> 4 years and < 70 years) undergoing multimodal therapy in tertiary care vascular anomalies centers will be included in this prospective observational trial. Treatment options include conservative management, medical therapy, minimally invasive image-guided procedures (embolization, sclerotherapy) and surgery as well as combinations of the latter. The primary outcome is the patient-reported QoL 6 months after completion of treatment using the short form-36 health survey version 2 (SF-36v2) and the corresponding short form-10 health survey (SF-10) for children. In addition, clinical presentation (physician-reported signs), MRI imaging (radiological assessment of devascularization), recurrence rate, and therapeutic safety will be analyzed. Further follow-up will be performed after 12, 24, and 36 months. Moreover, liquid biopsies are being obtained from peripheral blood at multiple time points to investigate potential biomarkers for therapy response and disease progression. DISCUSSION: The APOLLON trial is a prospective, multicenter, observational open-label trial with unequal study groups to generate prospective evidence for multimodal treatment of AVMs. A multicenter design with the potential to assess larger populations will provide an increased understanding of multimodal therapy outcome in this orphan disease. TRIAL REGISTRATION: German Clinical Trials Register (identification number: DRKS00021019) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00021019 .

External validation of the Ruptured Arteriovenous Malformation Grading Scale (RAGS) in a multicenter adult cohort.

PURPOSE: While Ruptured Arteriovenous Malformation Grading Scale (RAGS) has recently been validated in children, the literature lacks validation on adults exclusively. Therefore, we aimed to determine the validity of RAGS on the external multicenter adult cohort and compare its accuracy with other scales. METHODS: A retrospective analysis was performed in five neurosurgical departments to extract patients who presented with the first episode of acute brain arteriovenous malformation (bAVM) rupture between 2012 and 2019. Standard logistic regression and area under the receiver operating curve (AUROC) calculations were performed to determine the value of the following scales: intracerebral hemorrhage (ICH), AVM-associated ICH (AVICH), Spetzler-Martin (SM), Supplemented SM (Supp-SM), Hunt and Hess (HH), Glasgow Coma Scale (GCS), World Federation of Neurological Surgeons (WFNS), and RAGS to predict change in categorical and dichotomized modified Rankin Scale (mRS) across three follow-up periods: within the 6 months, 6 months to 1 year, and above 1 year. RESULTS: Sixty-one individuals with a mean age of 43.6 years were included. The RAGS outperformed other grading scales during all follow-up time frames. It showed AUROC of 0.78, 0.74, and 0.71 at the first 6 months, between 6 and 12 months, and after 12 months of follow-up, respectively, when categorized mRS was applied, while corresponding values were 0.79, 0.76, and 0.73 for dichotomized mRS, respectively. CONCLUSION: The RAGS constitutes a reliable scale predicting clinical outcomes following bAVM rupture among adults. Furthermore, the RAGS proved its generalizability across medical centers with varying treatment preferences.

Recurrent pulmonary arteriovenous malformation in a patient with Sjögren syndrome: A case report.

RATIONALE: Pulmonary manifestations of Sjögren syndrome (SS) are variable and may involve the airway or lung parenchyma and increase the risk of vascular and malignant disease. However, to date, only one case of pulmonary arteriovenous malformation (AVM) has been reported in a patient with SS. Here, we report a rare case of recurrent pulmonary AVMs with aggravating multiple cysts in a patient with SS during a period of 14 years. PATIENT CONCERNS: A 45-year-old woman was diagnosed with SS and pulmonary AVM in the right lung. Her AVMs were embolized successfully and she was followed up annually for 14 years. Eleven years after the initial treatment, her chest computed tomography showed new pulmonary AVMs in the left lung with aggravating multiple cysts. DIAGNOSIS: We diagnosed her with SS according to the American-European consensus group criteria of 2010. Chest computed tomography and angiographic findings confirmed the recurrence of pulmonary AVMs. INTERVENTIONS: The patient's recurrent pulmonary AVMs were successfully treated by embolization. OUTCOMES: Although her multiple cystic lung lesions had been aggravating during 14 years, she received embolization for the pulmonary AVMs twice and developed no complication related to these procedures. Currently, the patient is 56 years old and still alive with good performance state. LESSONS: To date, only one case of pulmonary AVM has been reported in a patient with SS. The patient died 2.5 years after the diagnosis without recurrence of AVM. Here, we present a rare case of recurrent pulmonary AVMs associated with aggravating multiple cysts in both lungs, which were observed during long-term follow-up, in a patient with SS.

Long-term follow-up in patients with brain arteriovenous malformation based on the Quality of Life Scale and socioeconomic status.

OBJECTIVE: Intracranial haemorrhage (ICH) is associated with permanent neurological disability resulting in deterioration of the quality of life (QoL). Our study assesses QoL in patients with ruptured arteriovenous malformation (AVM) in long-term follow-up at least five years after ICH and compares their QoL with the QoL of patient with non-ruptured AVM. METHODS: Using the Quality of Life Scale (QOLS), the Patient Health Questionnaire (PHQ-9) for depressive symptoms, and the socioeconomic status (SES), a prospective assessment was performed. The modified Rankin Scale (mRS) was assessed for outcome. RESULTS: Of 73 patients, 42 (57.5%) had ruptured (group 1) and 31 (42.5%) a non-ruptured AVM (group 2). Mean follow-up time was 8.6 ± 3.9 years (8.5 ± 4.2 years in group 1 and 8.9 ± 3.7 years in group 2). Favourable outcome (mRS 0-1) was assessed in 60 (83.3%) and unfavourable in 12 (16.7%) patients. Thirty-one of 42 patients (73.8%) in group 1 and 29 of 30 patients in group 2 (96.7%) had favourable outcomes. Mean QOLS was 85.6 ± 14.1 (group 1 86.1 ± 15.9, group 2 84.9 ± 11.4). Patients in group 1 did not show a significant difference in QoL compared to patients in group 2 (p = 0.23). Additional analyses in group 2 (rho = - 0.73; p < 0.01) and in untreated AVM patients (rho = - 0.81; p < 0.01) showed a strong correlation between QOLS and PHQ-9. CONCLUSION: Long-term follow-up showed no difference in the QoL between patients with and without ICH caused by brain AVM. Outcome- and QoL-scores were high in both groups. Further studies are necessary to evaluate depression and anxiety symptoms in patients with AVM.

Cerebral arterio-venous malformations hemodynamics changes in hereditary hemorrhagic telangiectasia - case report.

BACKGROUND: Spontaneous obliteration of cerebral arteriovenous malformations (AVMs) is a rare phenomenon. Hereditary Hemorrhagic Telangiectasia (HHT) is a predisposal genetic condition for AVMs development in all organs. CASE ILLUSTRATION: We report the case of a 34 years old woman with HHT family history. After radiosurgical treatment of a symptomatic evolving cerebellar AVM, late control subtracted digital angiography (DSA) demonstrated the complete obliteration of this AVM but also spontaneous obliteration of 3 fronto-parietal AVMs without any hemorrhagic sign on MRI. CONCLUSION: To our knowledge, this is the first report of spontaneous obliteration of multiple and unruptured AVMs in a HTT case.

External validation of brain arteriovenous malformation haemorrhage scores, AVICH, ICH and R2eD.

PURPOSE: To externally validate the arteriovenous malformation-related intracerebral haemorrhage (AVICH), intracerebral haemorrhage (ICH), and novel haemorrhage presentation risk score (R2eD) in brain arteriovenous malformations. METHODS: Adult patients diagnosed radiologically with an arteriovenous malformation (AVM) at a tertiary neurosurgical centre between 2007 and 2018 were eligible for inclusion. Both the AVICH and ICH scores were calculated for AVM-related symptomatic haemorrhage (SH) and compared against the modified Rankin scale (mRS) at discharge and last follow-up, with unfavourable outcome defined as mRS > 2. R2eD scores were stratified based on presentation with SH. External validity was assessed using Harrel's C-statistic. RESULTS: Two hundred fifty patients were included. Mean age at diagnosis was 46.2 years [SD = 16.5]). Eighty-seven patients (34.8%) had a SH, with 83 included in the analysis. Unfavourable mRS outcome was seen in 18 (21.6%) patients at discharge and 18 (21.6%) patients at last follow-up. The AVICH score C-statistic was 0.67 (95% confidence interval [CI], 0.53-0.80) at discharge and 0.70 (95% CI, 0.56-0.84) at last follow-up. The ICH score C-statistic was 0.78 (95% CI 0.67-0.88), at discharge and 0.80 (95% CI 0.69-0.91) at last follow-up. The R2eD score C-statistic for predicting AVM haemorrhage was 0.60 (95% CI, 0.53-0.67). CONCLUSIONS: The AVICH score showed fair-poor performance, while the ICH score showed good-fair performance. The R2eD score demonstrated poor performance, and its clinical utility in predicting AVM haemorrhage remains unclear.

State of the Art and Future Direction in Diagnosis, Molecular Biology, Genetics, and Treatment of Brain Arteriovenous Malformations.

Brain arteriovenous malformations (bAVMs) are uncommon and represent a heterogeneous group of lesions. Although these 2 facts have delayed research on this topic, knowledge about the pathophysiology, diagnosis, and treatment of bAVMs has evolved in recent years. We conducted a review of the literature to update the knowledge about diagnosis, molecular biology, genetic, pathology, and treatment by searching for the following terms: "Epidemiology AND Natural History," "risk of hemorrhage," "intracranial hemorrhage," "diagnosis," "angiogenesis," "molecular genetics," "VEGF," "KRAS," "radiosurgery," "endovascular," "microsurgery," or "surgical resection." Our understanding of bAVMs has significantly evolved in recent years. The latest investigations have helped in defining some molecular pathways involved in the pathology of bAVM. Although there is still more to learn and discover, describing these pathways will allow the creation of targeted treatments that could improve the prognosis of patients with bAVMs.

Molecular Biomarkers and Drug Targets in Brain Arteriovenous and Cavernous Malformations: Where Are We?

Vascular malformations of the brain (VMB) comprise abnormal development of blood vessels. A small fraction of VMBs causes hemorrhages with neurological morbidity and risk of mortality in patients. Most often, they are symptomatically silent and are detected at advanced stages of disease progression. The most common forms of VMBs are arteriovenous and cavernous malformations in the brain. Radiopathological features of these diseases are complex with high phenotypic variability. Early detection of these malformations followed by preclusion of severe neurological deficits such as hemorrhage and stroke is crucial in the clinical management of patients with VMBs. The technological advances in high-throughput omics platforms have currently infused a zest in translational research in VMBs. Besides finding novel biomarkers and therapeutic targets, these studies have withal contributed significantly to the understanding of the etiopathogenesis of VMBs. Here we discuss the recent advances in predictive and prognostic biomarker research in sporadic and familial arteriovenous malformations as well as cerebral cavernous malformations. Furthermore, we analyze the clinical applicability of protein and noncoding RNA-based molecular-targeted therapies which may have a potentially key role in disease management.

Ring finger protein 213 c.14576G>A mutation is not involved in internal carotid artery and middle cerebral artery dysplasia.

The ring finger protein 213 (RNF213) susceptibility gene has been detected in more than 80% of Japanese and Korean patients with moyamoya disease (MMD), a bilateral internal carotid artery (ICA) occlusion. Furthermore, RNF213 has been detected in more than 20% of East Asians with atherosclerotic ICA stenosis. In this study, we evaluated the frequency of RNF213 mutations in congenital occlusive lesions of the ICA system. This case series was conducted jointly at four university hospitals. Patients with a family history of MMD, quasi-MMD, or related diseases were excluded. Ten patients were diagnosed with abnormal ICA or middle cerebral artery (MCA) angiogenesis. Patients with neurofibromatosis were excluded. Finally, nine patients with congenital vascular abnormalities were selected; of these, five had ICA deficiency and four had twig-like MCA. The RNF213 c.14576G > A mutation was absent in all patients. Therefore, the RNF213 c.14576G > A mutation may not be associated with ICA and MCA congenital dysplasia-rare vascular anomalies making it difficult to study a large number of cases. However, an accumulation of cases is required for accurate determination. The results of this study may help differentiate congenital vascular diseases from MMD.

Intracranial Vascular Abnormalities in Children.

Intracranial vascular abnormalities rarely are encountered in primary care. Many of the pathologies are occult and prognosis varies widely between inconsequential variants of anatomy to acutely life-threatening conditions. Consequently, there often is a great deal of anxiety associated with any potential diagnosis. This article reviews anatomic intracranial vascular lesions, including vascular malformations (arteriovenous malformations/arteriovenous fistulae and cavernous malformations), structural arteriopathies (aneurysms and moyamoya), and common developmental anomalies of the vasculature. The focus includes a general overview of anatomy, pathology, epidemiology, and key aspects of evaluation for the primary care provider and a review of common questions encountered in practice.

The predictors of clinical outcomes in brainstem arteriovenous malformations after stereotactic radiosurgery.

ABSTRACT: The brainstem arteriovenous malformations (BS-AVMs) have a high morbidity and mortality and stereotactic radiosurgery (SRS) has been widely used to treat BS-AVMs. However, no consensus is reached in the explicit predictors of obliteration for BS-AVMs after SRS.To identify the predictors of clinical outcomes for BS-AVMs treated by SRS, we performed a retrospective observational study of BS-AVMs patients treated by SRS at our institution from 2006 to 2016. The primary outcomes were obliteration of nidus and favorable outcomes (AVM nidus obliteration with mRS score ≤2). For getting the outcomes more accurate, we also pooled the results of previous studies as well as our study by meta-analysis.A total of 26 patients diagnosed with BS-AVMs, with mean volume of 2.6 ml, were treated with SRS. Hemorrhage presentation accounted for 69% of these patients. Overall obliteration rate was 42% with mean follow-up of more than five years and two patients (8%) had a post-SRS hemorrhage. Favorable outcomes were observed in 8 patients (31%). Higher margin dose (>15Gy) was associated with higher obliteration (P = .042) and small volume of nidus was associated with favorable outcomes (P = .036). After pooling the results of 7 studies and present study, non-prior embolization (P = .049) and higher margin dose (P = .04) were associated with higher obliteration rate, in addition, the lower Virginia Radiosurgery AVM Scale (VRAS) was associated with favorable outcomes (P = .02) of BS-AVMs after SRS.In the BS-AVMs patients treated by SRS, higher margin dose (19-24Gy) and non-prior embolization were the independent predictors of higher obliteration rate. In addition, smaller volume of nidus and lower VRAS were the potential predictors of long-term favorable outcomes for these patients.