Arteriovenous Malformations Characteristics Research Articles

Timing of Embolization, Radiosurgery, and Resection of Arteriovenous Malformations in Pediatric Patients: A Retrospective, Descriptive Study

ObjectiveCerebral arteriovenous malformations (AVMs) are a challenging pathology in pediatric patients, carrying a high risk of morbidity and mortality. Treatment modalities include resection, endovascular embolization and stereotactic radiosurgery (SRS). There is currently no consensus favoring one modality over another. Timing of multimodal therapy with embolization/SRS and resection is not well explored in the literature. Here we present a series of pediatric AVM patients, with special attention paid to the timing of treatment. MethodsElectronic medical records of all pediatric patients (<18 years at treatment) with AVMs treated at our institution were retrospectively reviewed after IRB approval. Demographic information, AVM characteristics, treatment variables and outcomes were recorded. Results27 total patients were included. 21 (77.8%) presented with a ruptured AVM. 6 patients (28.6%) had an GCS of 3 to 10, and underwent treatment within 24 hours of presentation. 10 patients (47.6 %) with a GCS of 12 to 15 were treated between 24 to 120 hours. 5 patients (23.8%) were treated 3 weeks to 14 months after AVM rupture. 96% of our cohort, regardless of rupture status, had mRS of 1-2 at most recent follow-up. ConclusionsWe present our institution’s experience with pediatric AVM’s, focusing on the timing of treatment. Based on our experience, early treatment of AVMs seems to be safe and effective regardless of rupture status.

Microsurgery of Cerebral Arteriovenous Malformations in a Resource-Limited Setting: The First Case-Series from Iraq

Cerebral arteriovenous malformations (AVMs) can lead to significant morbidity and are particularly challenging to manage in resource-limited settings where endovascular treatment modalities are unaffordable for most patients. To describe the first case series of AVM from Iraq with an analysis of the related clinicoradiologic characteristics, operative features, and outcomes. A single-center database from October 2018 to December 2022 was reviewed to analyze the characteristics of cerebral AVMs who underwent surgical treatment in Baghdad, Iraq. We collected patient demographics, clinical, radiologic, operative, and the follow-up combined outcome results (modified Rankin Scale score and the presence of AVM remnants). Of the 54 AVM patients treated with microsurgery, the majority of lesions have Spetzler-Martin grade of 3 (31.5%), followed by grade 1 (29.6%). The parietal lobe was the most common location of AVM in 25.9% of the cases, and the temporal location had better outcomes. The mean duration of surgery was 8.5 hours, ranging from 3 to 14 hours, with 20.3% of cases having undergone preoperative stereotactic radiosurgery, and just one patient received preoperative embolization. Good combined outcome (modified Rankin Scale 0-2 and no AVM remnant) was associated with lower SM grades (P=0.003); location in the nondominant hemisphere (P=0.036), and noneloquent regions (P=0.006); absence of deep venous drainage (P=0.042) and no intraoperative brain swelling (P=0.004). The mortality rate in our series was 5.5%. Good clinicoradiologic outcomes can be achieved through microsurgery in a setting where endovascular treatment is inaccessible to patients due to limited resources.

Characterization of Pediatric Infratentorial Arteriovenous Malformations: A Retrospective, Multicenter Cohort Study.

Infratentorial arteriovenous malformations (AVMs) harbor different characteristics compared with supratentorial AVMs. This study aims to explore the unique characteristics of pediatric infratentorial AVMs and their response to single session stereotactic radiosurgery (SRS). The International Radiosurgery Research Foundation database of pediatric patients with AVM (age <18 years) who underwent SRS was retrospectively reviewed. Baseline demographics, AVM characteristics, outcomes, and complications post-SRS were compared between infratentorial and supratentorial pediatric AVMs. Unfavorable outcome was defined as the absence of AVM obliteration, post-SRS hemorrhage, or permanent radiation-induced changes at last follow-up. A total of 535 pediatric AVMs managed with SRS with a median follow-up of 67 months (IQR 29.0-130.6) were included, with 69 being infratentorial and 466 supratentorial. The infratentorial group had a higher proportion of deep location (58.4% vs 30.3%, P = <.001), deep venous drainage (79.8% vs 61.8%, P = .004), and prior embolization (26.1% vs 15.7%, P = .032). There was a higher proportion of hemorrhagic presentation in the infratentorial group (79.7% vs 71.3%, P = .146). There was no statistically significant difference in the odds of an unfavorable outcome (odds ratio [OR] = 1.36 [0.82-2.28]), AVM obliteration (OR = 0.85 [0.5-1.43]), post-SRS hemorrhage (OR = 0.83 [0.31-2.18]), or radiologic radiation-induced changes (OR = 1.08 [0.63-1.84]) between both cohorts. No statistically significant difference on the rates of outcomes of interest and complications were found in the adjusted model. Despite baseline differences between infratentorial and supratentorial pediatric AVMs, SRS outcomes, including AVM obliteration and post-SRS hemorrhage rates, were comparable amongst both groups. SRS appears to have a similar risk profile and therapeutic benefit to infratentorial pediatric AVMs as it does for those with a supratentorial location.

Quantitative Assessment of Hemodynamics Associated With Embolization Degree in Brain Arteriovenous Malformations.

Grading systems, including the novel brain arteriovenous malformation endovascular grading scale (NBAVMES) and arteriovenous malformation embocure score (AVMES), predict embolization outcomes based on arteriovenous malformation (AVM) morphological features. The influence of hemodynamics on embolization outcomes remains unexplored. In this study, we investigated the relationship between hemodynamics and embolization outcomes. We conducted a retrospective study of 99 consecutive patients who underwent transarterial embolization at our institution between 2012 and 2018. Hemodynamic features of AVMs were derived from pre-embolization digital subtraction angiography sequences using quantitative digital subtraction angiography. Multivariate logistic regression analysis was performed to determine the significant factors associated with embolization outcomes. Complete embolization (CE) was achieved in 17 (17.2%) patients, and near-complete embolization was achieved in 18 (18.2%) patients. A slower transnidal relative velocity (TRV, odds ratio [OR] = 0.71, P = .002) was significantly associated with CE. Moreover, higher stasis index of the drainage vein (OR = 16.53, P = .023), shorter transnidal time (OR = 0.15, P = .013), and slower TRV (OR = 0.9, P = .049) were significantly associated with complete or near-complete embolization (C/nCE). The area under the receiver operating characteristic curve for predicting CE was 0.87 for TRV, 0.72 for NBAVMES scores (ρ = 0.287, P = .004), and 0.76 for AVMES scores. The area under the receiver operating characteristic curve for predicting C/nCE was 0.77 for TRV, 0.61 for NBAVMES scores, and 0.75 for AVMES scores. Significant Spearman correlation was observed between TRV and NBAVMES scores and AVMES scores (ρ = 0.512, P < .001). Preoperative hemodynamic factors have the potential to predict the outcomes of AVM embolization. A higher stasis index of the drainage vein, slower TRV, and shorter transnidal time may indicate a moderate blood flow status or favorable AVM characteristics that can potentially facilitate embolization.

Treatment outcomes for ARUBA-eligible brain arteriovenous malformations: a comparison of real-world data from the NVQI-QOD AVM registry with the ARUBA trial

BackgroundSignificant controversy exists about the management of unruptured cerebral arteriovenous malformations (AVMs). Results from A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) suggested that intervention increases the risk of...

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series

We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs). We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis. Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage. Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

Microsurgical Treatment of Arteriovenous Malformations: A Single-Center Study Experience.

The purpose of the study was to assess the functional outcomes after microsurgical resection of arteriovenous malformations (AVMs) and to compare the results between patients eligible for A Randomized Trial of Unruptured Brain Arteriovenous Malformations in this surgical series to the results reported and the ARUBA study. We reviewed the records of 169 patients who underwent microsurgical treatment of arteriovenous malformation (AVMs) in our institution between January 2016 and December 2021. These patients' functional status was assessed using modified Rankin Scale (mRS) scores at the last follow-up and before treatment. The mRS scores at the latest follow-up were classified into good outcomes (mRS < 3) and poor outcomes (mRS ≥ 3). Clinical presentation, patients' demographics, AVM characteristics, follow-up time, and obliteration rate were analyzed. Subgroup analyses were performed on the whole cohort, comparing Spetzler-Martin Grade I and Grade II, and ARUBA-eligible AVMs. The initial hemorrhagic presentation occurred in 71 (42%) out of 169 patients. The majority of the patients presented with headaches (73%). The AVMs were completely obliterated in 166 (98.2%) patients. The series included 65 Spetzler-Martin Grade I (38.5%), 46 Grade II (27.2%), 32 Grade III (18.9%), 22 Grade IV (13%), and 4 Grade V (2.4%) AVMs. There were 98 unruptured and 79 ARUBA-eligible cases. Also, optimal functional outcome was achieved in 145 (85.8%) patients. The overall mortality rate was 5.3% (9/169). The multivariate analysis illustrated that a poor outcome was significantly associated with presurgical mRS ≥3 (p < 0.013; OR, 0.206; 95% CI 0.059-0.713), increasing age (p < 0.045; odds ratio [OR], 1.022; 95% CI 1.000-0.045), and female gender (p < 0.009; OR, 2.991; 95% CI 1.309-6.832). Our study suggests that better outcomes can be obtained using microsurgical resection in the majority of patients with AVMs. Independent predictors of poor outcomes after surgical resection of AVMs include increasing age at the time of surgery, poor presurgical functional status, and female gender. Supposing that patients are more suitable for microsurgery after presurgical examination, outcomes are normally better in that case than those achieved by multimodal interventions (such as conservative treatment or ARUBA treatment arm). Therefore, we recommend early surgical removal on all surgically accessible AVMs to prevent successive hemorrhages and the consequences of poor neurological outcomes.

Endovascular Treatment of Peripheral Arteriovenous Malformations (AVMs): Do Angiographic Outcomes Relate to the Quality of Life?

Purpose: Patients with arteriovenous malformations (AVMs) have a lower health-related quality of life (QoL) than the general population. QoL assessment of patients with peripheral AVMs after endovascular treatment is scarce in the literature. Radiologic and clinical outcomes are not always correlated in vascular malformation treatment. This study aimed to investigate the relationship between clinical outcomes, QoL, and angiographic outcomes. Materials and Methods: Patients with peripheral AVM that underwent endovascular treatment between January 2009 and December 2021 in a single center were retrospectively evaluated. Patients’ characteristics (age, sex), AVM characteristics (Schobinger classification, location, angiographic architecture), previous treatment, treatment characteristics (type of endovascular approach, embolizing agent and number of sessions), percentages of angiographic response, complications, and recurrence were evaluated. The angiographic architecture was evaluated according to the Yakes classification. The questionnaire was applied for evaluation of clinical response and QoL. Patients older than 12 years and those who can be contacted were included in clinical and QoL analysis. Clinical response was defined as improvement in the patient’s most important pretreatment symptom. Treatment response was defined as clinical response plus >50% angiographic response. Results: Eighty-six patients (41 males [47.7%], 45 females [52.3%]) were included in angiographic analysis. The mean age was 28.44±12.99 years (range=5–61). Forty-three patients (50%) had previous treatment. The median number of sessions was 2 (range 1–15, InterQuartile Range [IOR]=2). Sixty-one patients (30 males [49.2%], 31 females [50.8%]) were included in clinical analysis. The clinical response rate was 73.8%, 95% confidence interval (CI) [0.60, 0.84]. The treatment response rate was 45.9%, 95% CI [0.33, 0.59]. The complication rate was 8.2%. Before treatment, 48 patients (78.7%) reported a negative impact on their QoL. Thirty-three of 48 patients (68.8%) reported improvement on their QoL after treatment. Higher Schobinger stages were related to a negative impact on QoL before treatment (p<0.01). Yakes types were not related to QoL (p=0.065). Clinical response was related to improvement on QoL after treatment (p<0.01). Angiographic and treatment responses were not related to improved QoL after treatment (p=0.52 and p=0.055, respectively). Conclusion: Angiographic architecture and outcomes were not always reflected in QoL after endovascular treatment. Clinical Impact This study’s findings will help clinicians with what to focus on in AVM treatment and how to monitor patients with peripheral AVM after endovascular treatment. Rather than relying too much on the angiographic response, patients should be checked for symptoms and quality of life improvement. No clear data in the literature regarding the applicability of the Yakes Classification in patients with previous treatment. This study questioned the applicability of the Yakes Classification in patients with previous treatments. In this study, type 4 AVMs were more common in patients with previous treatment.

Abstract No. 197 Efficacy and Safety of Transarterial Bleomycin Sclerotherapy of Early-Stage Facial Arteriovenous Malformation: Single-Center Multidisciplinary Team Experience

To evaluate the efficacy and safety of transarterial bleomycin sclerotherapy of early-stage facial arteriovenous malformation (AVM). A retrospective review was performed of patients who underwent bleomycin sclerotherapy for early-stage AVM (Schobinger stage I or II) in a single-referral vascular anomalies center. Bleomycin was slowly infused transarterially with flow control techniques to prolong the effects of bleomycin. Procedure details, AVM characteristics, and previous treatments were reviewed. Initial therapeutic outcomes were determined by 5 categories using both radiologic and clinical findings in a 6-month follow-up. Further follow-up outcomes were reviewed to evaluate the long-term efficacy and safety of the treatment. Procedure-related complications were also analyzed. Nineteen patients (mean age, 22.4 ± 14.0 years, 14 female) with 31 sessions of sclerotherapies were enrolled. All AVMs were Cho-Do classification type III (type IIIa [n = 13], type IIIb [n = 2], and type IIIa+b [n = 4]). Patients received a mean of 1.6 (range, 1-4) sessions of treatment. The mean cumulative bleomycin dose was 23600 IU ± 14500 (range, 8000–60000 IU). The results showed that 14 patients (74%) patients were responsive to transarterial bleomycin sclerotherapy, including complete response (n = 3), marked improvement (n = 1), and partial improvement (n = 10). The remaining 5 (26%) showed no response. During a mean follow-up of 32.6 months, 5 (26%) showed slight aggravation compared with 6-month outcomes and 14 (74%) were stable. There were only 2 minor complications [hyperpigmentation (n = 1) and cellulitis (n = 1)]. Transarterial bleomycin sclerotherapy using flow control techniques can be a safe and feasible alternative treatment option for facial early-stage AVM.

Efficacy and safety of transarterial bleomycin sclerotherapy of early-stage facial arteriovenous malformation: Single-center multidisciplinary team experience

To evaluate the efficacy and safety of transarterial bleomycin sclerotherapy of early-stage facial arteriovenous malformation (AVM). A retrospective review was performed of patients who underwent bleomycin sclerotherapy for early-stage AVM (Schobinger stage I or II) in a single-referral vascular anomalies center. Bleomycin was slowly infused transarterially with flow control techniques to prolong the effects of bleomycin. Procedure details, AVM characteristics, and previous treatments were reviewed. Initial therapeutic outcomes were determined by 5 categories using both radiological and clinical findings in a 6-month follow-up. Further follow-up outcomes were reviewed to evaluate the long-term efficacy and safety of the treatment. Procedure-related complications were also analyzed. Nineteen patients (mean age 22.4±14.0 years, 14 females) with 31 sessions of sclerotherapies were enrolled. All AVMs were Cho-Do classification type III (type IIIa [n=13], type IIIb [n=2], and type IIIa+b [n=4]). Patients received a mean of 1.6 (range, 1-4) sessions of treatment. The mean cumulative bleomycin dose was 23,600 IU ± 14,500 (range, 8000 - 60,000 IU). The results showed that 14 patients (74%) were responsive to transarterial bleomycin sclerotherapy, including complete response (n=3), marked improvement (n=1), and partial improvement (n=10). The remaining 5 (26%) showed no response. During a mean follow-up of 32.6 months, 5 (26%) showed slight progression compared with 6-month outcomes and 14 (74%) were stable. There were only 2 minor complications [hyperpigmentation (n=1) and cellulitis (n=1)]. Transarterial bleomycin sclerotherapy using flow control techniques can be a safe and feasible alternative treatment option for facial early-stage AVM.

Clinical Characteristics and Multimodality Therapy Outcomes in 304 Pediatric Patients with Cerebral Arteriovenous Malformations

Clinical follow-up data of pediatric patients with cerebral arteriovenous malformations (AVMs) are limited. This study investigated the characteristics of AVMs in children and analyzed the clinical outcomes of multimodality therapy in pediatric patients with AVMs at a single center. This retrospective study included consecutive patients diagnosed with AVMs at our institution between August 2008 and June 2018. Data on demographic characteristics, AVM features, and clinical outcomes were collected. Patients aged <18years at admission were defined as children. Overall, 1009 patients with AVMs were included, with 304 (30.1%) patients aged <18years. AVMs in pediatric patients were more likely to present with intracranial hemorrhage, mostly located in deep areas of the brain. A small nidus, exclusively deep drainage, and deep AVM location were associated with hemorrhage in children; Kaplan-Meier analysis revealed that patients with ruptured AVMs had a higher risk of developing a follow-up hemorrhage than those with unruptured AVMs. Among 290 children who were followed up, the multivariate regression analysis showed that a higher pretreatment modified Rankin Scale score, deep AVM location, and conservative treatment were significantly associated with unfavorable outcomes. In pediatric patients, AVMs were more likely to present with intracranial hemorrhage than that in adults. Hemorrhagic presentation in children was associated with a small nidus, exclusively deep drainage, and deep AVM location. Pediatric patients with ruptured AVMs had significantly higher risks of follow-up hemorrhage than those with unruptured AVMs. Our clinical results suggest that nonconservative treatment is better for pediatric patients with AVMs.

Interventional outcomes for patients eligible for entry into the ARUBA clinical trial: a systematic review and meta-analysis.

A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) suggested that medical management afforded outcomes superior to those following intervention for unruptured arteriovenous malformations (AVMs), but its findings have been controversial. Subsequent studies of AVMs that would have met the eligibility requirements of ARUBA have supported intervention for the management of some cases. The present meta-analysis was conducted with the object of summarizing interventional outcomes for ARUBA-eligible patients reported in the literature. A systematic literature search (PubMed, Web of Science, Google Scholar) for AVM intervention studies that used inclusion criteria identical to those of ARUBA (age ≥ 18 years, no history of AVM hemorrhage, no prior intervention) was performed. The primary outcome was death or symptomatic stroke. Secondary outcomes included AVM obliteration, hemorrhage, death, and poor outcome (modified Rankin Scale score ≥ 2 at final follow-up). Bias assessment was performed with the Newcastle-Ottawa Scale, and the results were synthesized as pooled proportions. Of the 343 articles identified through database searches, 13 studies met the inclusion criteria, yielding an overall study cohort of 1909 patients. The primary outcome occurred in 11.2% of patients (pooled = 11%, 95% CI 8%-13%). The rates of AVM obliteration, hemorrhage, poor outcome, and death were 72.7% (pooled = 78%, 95% CI 70%-85%), 8.4% (pooled = 8%, 95% CI 6%-11%), 9.9% (pooled = 10%, 95% CI 7%-13%), and 3.5% (pooled = 2%, 95% CI 1%-4%), respectively. Annualized primary outcome and hemorrhage risks were 1.85 (pooled = 2.05, 95% CI 1.31-2.94) and 1.34 (pooled = 1.41, 95% CI 0.83-2.13) per 100 patient-years, respectively. Intervention for unruptured AVMs affords acceptable outcomes for appropriately selected patients. The risk of hemorrhage following intervention compared favorably to the natural history of unruptured AVMs. The included studies were retrospective and varied in treatment and AVM characteristics, thereby limiting the generalizability of their data. Future studies from prospective registries may clarify patient, nidus, and intervention selection criteria that will refine the challenging management of patients with unruptured AVMs.

Comparison of transarterial n-BCA and Onyx embolization of brain arteriovenous malformations: A single-center 18-year retrospective analysis.

ObjectiveBrain arteriovenous malformations (AVM) are commonly treated with endovascular embolization. Due to the rapid evolution of endovascular technology and lack of consistent practice guidelines regarding AVM embolization, further study of AVM embolization outcomes is warranted.MethodsWe conducted a retrospective review of AVMs embolized at a single center from 2002-2019. Patient demographics, AVM characteristics, intention of embolization, and angiographic and clinical outcome after embolization were recorded. We compared the embolization results of those treated with n-butyl cyanoacrylate (n-BCA) and Onyx.ResultsOver an 18-year period at our institution, 30 (33%) of 92 AVMs were treated with embolization. n-BCA was used in 12 cases and Onyx in 18 cases. Eighty-seven pedicles were embolized over 47 embolization sessions. Fifty percent of AVMs treated with n-BCA underwent more than one embolization session compared to 22% when Onyx was used. The median total percent volume reduction in the n-BCA AVMs was 52% compared to 51% in Onyx AVMs. There were 2 periprocedural complications in the n-BCA cohort and none in the Onyx cohort.ConclusionsIn this small retrospective series, Onyx and n-BCA achieved similar occlusion results, although n-BCA required more sessions and pedicles embolized to do so.

A Rational Approach to the Management of Cerebral Arteriovenous Malformations

Cerebral arteriovenous malformations (AVMs) typify the delicate balance cerebrovascular specialists face in weighing the treatment risk against the natural history of a pathologic lesion. The goal of our review was to provide an overview of the current evidence for the treatment of cerebral AVMs and describe a contemporary approach to developing a treatment strategy according to individual AVM characteristics. A review of the contemporary literature on the natural history and treatment of cerebral AVMs was completed through the PubMed and Google Scholar databases. The studies were reviewed for original advances in the characterization and treatment of cerebral AVMs. The overall risk of hemorrhage for cerebral AVMs is 2%-4% per year. Individual AVM characteristics, including small size, exclusive deep venous drainage, deep or posterior fossa location, venous ectasia, and the presence of a flow-associated aneurysm, appear to confer a greater risk of presentation with rupture. A diverse array of modalities have been developed to achieve the goal of complete lesion obliteration, including microsurgery, endovascular therapy, and radiosurgery. Advances in treatment strategies and technology have continued to decrease the morbidity associated with lesion obliteration. Microsurgical or multimodal treatment strategies are often required to achieve complete obliteration; however, it remains critical that each treatment approach is individualized by the specific AVM characteristics.

Predictive Factors for Arteriovenous Malformation Obliteration After Stereotactic Radiosurgery: A Single-Center Study

Stereotactic radiosurgery (SRS) is particularly useful for treatment of deep arteriovenous malformations (AVMs) in eloquent territory with a high associated surgical risk. Prior studies have demonstrated high rates of AVM obliteration with SRS (60%-80%) in a latency period of 2-4 years for complete obliteration. Studies have identified several factors associated with successful obliteration of the AVM nidus; however, these present inconsistent and conflicting data. The aim of this single-center study was to examine factors associated with successful obliteration of AVMs treated with SRS. A retrospective review was performed of 210 consecutive patients undergoing SRS for brain AVMs between 2010 and 2019. The χ2 test and logistic regression analysis were used to identify patient and AVM factors associated with successful obliteration. Younger age (P= 0.034) and prior embolization (P= 0.012) were associated with complete obliteration. The presence of coronary artery disease was associated with incomplete obliteration (P= 0.04). No AVM characteristics were statistically associated with complete obliteration, although superficial venous drainage (P= 0.08) and frontal location (P= 0.06) trended toward significance. Successful obliteration of the AVM nidus was significantly associated with younger age and prior embolization. The presence of coronary artery disease negatively affected obliteration rates. These results add to the mixed results seen in the literature and emphasize the need for continued studies to delineate more specific patient and AVM factors that contribute to successful obliteration.

Profile of the brain arteriovenous malformation at National Brain Center hospital in 2015 – 2016: Epidemiological study

Introduction: Brain arteriovenous malformation (AVM) is a congenital vascular lesion in which arterial blood flows directly into draining veins without capillary networking. The estimated incidence rate is approximately 1 case for 100,000 people a year. Clinical presentations are headache, seizure, neurological deficit, and others that are caused by space-occupying lesions. The treatment of brain AVM consists of microsurgery resection, embolization, stereotactic radiosurgery to conservative treatment.Methods: The design of the study was a descriptive non-analytical study. Data were taken from patients' medical records, radiological records, and catheter lab data records at National Brain Center Hospital in 2015 – 2016.Results: There were 32 patients with AVM. The characteristics of brain AVM in our study were mostly men (62.5%), productive age ranging from 20 – 29 years (31.25%), manifested as seizure (43.75%), presence with Glasgow Coma Scale (GCS) score 15 (87.5%), and rupture of brain AVM nidus (59.38%).Conclusion: Brain AVM predominantly occurred at a young age and the management varied on the Spetzler-Martin grading. In addition, the likelihood of rupture was influenced by the characteristics of the lesion, such as size, age, location of the nidus, and history of rupture of brain AVM nidus.Keywords: brain arteriovenous malformation, epidemiology, profile

Factors associated with seizures at initial presentation in pediatric patients with cerebral arteriovenous malformations.

Children with cerebral arteriovenous malformations (AVMs) can present with seizures, potentially increasing morbidity and impacting clinical management. However, the factors that lead to seizures as a presenting sign are not well defined. While AVM-related seizures have been described in case series, most studies have focused on adults and have included patients who developed seizures after an AVM rupture. To address this, the authors sought to analyze demographic and morphological characteristics of AVMs in a large cohort of children. The demographic, clinical, and AVM morphological characteristics of 189 pediatric patients from a single-center database were studied. Univariate and multivariate logistic regression models were used to test the effect of these characteristics on seizures as an initial presenting symptom in patients with unruptured brain AVMs. Overall, 28 of 189 patients initially presented with seizures (14.8%). By univariate comparison, frontal lobe location (p = 0.02), larger AVM size (p = 0.003), older patient age (p = 0.04), and the Supplemented Spetzler-Martin (Supp-SM) grade (0.0006) were associated with seizure presentation. Multivariate analysis confirmed an independent effect of frontal lobe AVM location and higher Supp-SM grade. All patients presenting with seizures had AVMs in the cortex or subcortical white matter. While children and adults share some risk factors for seizure presentation, their risk factor profiles do not entirely overlap. Pediatric patients with cortical AVMs in the frontal lobe were more likely to present with seizures. Additionally, the Supp-SM grade was highly associated with seizure presentation. Future clinical research should focus on the effect of therapeutic interventions targeting AVMs on seizure control in these patients.

Seizure Rates After Stereotactic Radiosurgery for Cerebral AVMs: A Single Center Study

Seizure control after stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is an area of growing interest, with previous studies reporting up to 70% seizure freedom after treatment. The goals of this study were to identify specific patient and AVM characteristics associated with seizure presentation and seizure outcomes after SRS treatment. A retrospective review of consecutive patients undergoing SRS for brain AVMs between 2009 and 2019 at our institution was conducted. Chi-squared and logistic regression analyses were utilized to identify patient and AVM factors associated with preoperative seizure presentation and development of new onset seizures after SRS. Two hundred ten consecutive patients presenting with AVMs treated with SRS were reviewed. Factors associated with seizure presentation included larger AVM size (P= 0.02), superficial venous drainage (P< 0.05), and parietal location (P= 0.04). Of 188 patients with follow-up (90%), 30 patients presented with seizures and 14 (47%) were seizure-free post-SRS. Of 158 patients presenting without seizure, 29 (18%) developed de novo seizures during follow-up. De novo post-SRS seizures were associated with prior craniotomy for resection of AVM (P= 0.04), post-treatment hemorrhage (P= 0.02), parietal location (P= 0.05), adverse effect requiring steroids (P < 0.01), and adverse effect requiring surgery (P < 0.01). Seizures are a common presentation of brain AVMs and can be treated effectively with SRS. However, seizures can also be a complication of SRS and are associated with post-treatment hemorrhage, edema, and need for future open surgery.

Cerebral Arteriovenous Malformations Treated With Linear Accelerator Stereotactic Radiosurgery Guided by Magnetic Resonance Imaging and Panangiography: A Latin American Experience

Cerebral arteriovenous malformations (AVM) are vascular lesions that include aberrant communication between arterial and venous systems. Treatment for AVM is still under debate. Surgery, embolization, observation, and radiosurgery are options for patients. Most data for radiosurgery came from the Gammaknife series. However, low middle-income countries have financial constraints to establish dedicated intracranial neurosurgery machines. We aimed to determine AVM obliteration rate in patients treated with linear accelerator stereotactic radiosurgery (SRS) guided by magnetic resonance imaging and panangiography fusion with computed tomography simulation at a quaternary care institution in Latin America.We conducted an observational study with patients treated with SRS at our institution during 2011 and 2017. Exclusion criteria were age younger than 14 and a history of brain cancer. After IRB approval, data were collected retrospectively by reviewing medical records. Patients without available follow-up were contacted to gather missing information. Primary outcome was obliteration rate at 3 years, confirmed by diagnostic imaging (MRI or cerebral panangiography). Secondary outcomes were intracranial bleeding, headaches, epilepsy, and neurological deficits at clinical presentation and after SRS. Analysis included sociodemographic data, AVM characteristics (location and Spetzler-Martin grading), and treatment features. We used descriptive statistics, measures of central tendency and dispersion, and proportions.We included 85 patients. The mean age at treatment was 40.8 (14-73), 49.4% of patients were male, and 50.6% female. The most common location was the frontal lobe in 25.9% (n = 22) and the parietal lobe in 24.7% (n = 21). At diagnosis, 44% of patients had a history of intracranial hemorrhage. 49 patients had received previous embolization. The mean dose of radiosurgery was 19.3 Gy (14-25). The mean isodose was 95.25 (80-98). 35.3% of the patients had an AVM Spetzler-Martin grade 2, 40% grade 3, and 12.9% grade 4. We obtained long-term follow-up data for 42 patients, with a median follow-up of 1366 days. The overall obliteration rate was 60%, based primarily on panangiography (59.1%). Symptoms after SRS included headaches (n = 30) and seizures (n = 10). 2 patients presented intracranial bleeding. We contacted all missing patients, but no follow-up data was available for analysis. Most missing patients lived outside the city.Tri-modality image fusion SRS with linear accelerators for AVM could be a safe and accessible option in low-middle income countries. Health administrator issues, travel distances to access linear accelerators and multidisciplinary teams hinder timely follow-up and surveillance imaging. More prospective data are needed to define the role of SRS for AVMs.V. Rangel: None. J. Cure: None. M. Caicedo-Martinez: None. G. Borda: None. C. Lindado: None. E. Castro-Lombana: None. J. Puentes: None. O. Zorro: None. A. González-Motta: None.

Angioarchitectural features amongst patients with unruptured brain arteriovenous malformations presenting with headache: findings from a single center retrospective review of 76 patients

BackgroundBrain arteriovenous malformations (AVMs) consist of abnormal connections between arteries and veins via an interposing nidus. While hemorrhage is the most common presentation, unruptured AVMs can present with headaches, seizures, neurological deficits, or be found incidentally. It remains unclear as to what AVM characteristics contribute to pain generation amongst unruptured AVM patients with headaches.MethodsTo assess this relationship, the current study evaluates angiographic and clinical features amongst patients with unruptured brain AVMs presenting with headache. Loyola University Medical Center medical records were queried for diagnostic codes corresponding to AVMs. In patients with unruptured AVMs, we analyzed the correlation between the presenting symptom of headache and various demographic and angiographic features.ResultsOf the 144 AVMs treated at our institution between 1980 and 2017, 76 were unruptured and had sufficient clinical data available. Twenty-three presented with headaches, while 53 patients had other presenting symptoms. Patients presenting with headache were less likely to have venous stenosis compared to those with a non-headache presentation (13 % vs. 36 %, p = 0.044).ConclusionsOur study suggests that the absence of venous stenosis may contribute to headache symptomatology. This serves as a basis for further study of correlations between AVM angioarchitecture and symptomatology to direct headache management in AVM patients.