Pediatric Arteriovenous Malformations Research Articles

P.125 Cerebral AVM recurrence post gamma knife obliteration: a 20 year single centre retrospective analysis and review of literature

Background: Pediatric arteriovenous malformations (AVMs) are rare, but represent the leading cause of intracranial hemorrhage in children. These are traditionally understood to be congenital lesions, however AVMs recurrence within previously unaffected tissue challenges this understanding. Recurrence after microsurgery and endovascular treatment have been studied in greater detail, but little literature exists surrounding recurrence after Gamma Knife Radiosurgery (GKRS). Methods: We performed a retrospective chart review of all pediatric AVMs treated with GKRS at our centre. Charts were assessed by two reviewers to identify cases of AVM recurrence after angiographically confirmed obliteration. To contextualize our institutional patterns, we also performed a structured literature review of published data reporting pediatric AVM recurrence after GKRS. Results: Our institutional review revealed two cases of AVM recurrence after angiographically proven cure, and our review of literature identified nine retrospective reviews and three case reports, which in total reported 22 individual cases of recurrence. The recurrence rate in the retrospective reviews ranged from 0 to 18%. Conclusions: The current work illustrates that while AVM recurrence is rare, it is a possible complication of GKRS. There was also a qualitative suggestion that embolization prior to CT increased risk of recurrence. Both these facts should be included in decision-making and patient counselling.

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.

Examining barriers to care: a retrospective cohort analysis investigating the relationship between hospital volume and outcomes in pediatric patients with cerebral arteriovenous malformations.

Comprehensive data on treatment patterns of pediatric cerebral arteriovenous malformations (AVMs) are lacking. The authors' aim was to examine national trends, assess the effect of hospital volume on outcomes, and identify variables associated with treatment at high-volume centers. Pediatric AVM admissions (for ruptured and unruptured lesions) occurring in the US in 2016 and 2019 were identified using the Kids' Inpatient Database. Demographics, treatment methods, costs, and outcomes were recorded. The effect of hospital AVM volume on outcomes and factors associated with treatment at higher-volume hospitals were analyzed. Among 2752 AVM admissions identified, 730 (26.5%) patients underwent craniotomy, endovascular treatment, or a combination. High-volume (vs low-volume) centers saw lower proportions of Black (8.7% vs 12.9%, p < 0.001) and lowest-income quartile (20.7% vs 27.9%, p < 0.001) patients, but were more likely to provide endovascular intervention (19.5%) than low-volume institutions (13.7%) (p = 0.001). Patients treated at high-volume hospitals had insignificantly lower numbers of complications (mean 2.66 vs 4.17, p = 0.105) but significantly lower odds of nonroutine discharge (OR 0.18 [95% CI 0.06-0.53], p = 0.009) and death (OR 0.13 [95% CI 0.02-0.75], p = 0.023). Admissions at high-volume hospitals cost more than at low-volume hospitals, regardless of whether intervention was performed ($64,811 vs $48,677, p = 0.001) or not ($64,137 vs $33,779, p < 0.001). Multivariable analysis demonstrated that Hispanic children, patients who received AVM treatment, and those in higher-income quartiles had higher odds of treatment at high-volume hospitals. In this largest study of US pediatric cerebral AVM admissions to date, higher hospital volume correlated with several better outcomes, particularly when patients underwent intervention. Multivariable analysis demonstrated that higher income and Hispanic race were associated with treatment at high-volume centers, where endovascular care is more common. The findings highlight the fact that ensuring access to appropriate treatment of patients of all races and socioeconomic classes must be a focus.

Management of Pediatric Intracranial Arteriovenous Malformations.

Pediatric intracranial arteriovenous malformations (AVMs) are challenging lesions managed by pediatric neurosurgeons. The high risk of hemorrhage and neurologic injury is compounded by the unique anatomy of each malformation that requires individualizing treatment options. This article reviews the current status of pediatric AVM epidemiology, pathophysiology and clinical care, with a specific focus on the rationale and methodology of surgical resection.

Pediatric Patients with Intracranial Arteriovenous Malformations: Trends in Emergency Room Presentation

Pediatric intracranial arteriovenous malformation (AVM) patients are commonly admitted to the emergency room (ER). Increasing patient utilization of the ER has been associated with healthcare disparities and a trend of decreased efficiency. Correspondingly, the aim of this study was to evaluate the trends of pediatric AVM ER admissions over recent years and identify factors associated with health care resource utilization and outcomes. The 2016-2019 National Inpatient Sample (NIS) was queried for patients under the age of 18 admitted with AVM. Cases of admission through the ER were identified. Demographic and severity factors associated with ER admission were explored using comparative and regression statistics. Of 3,875 pediatric patients with AVM admitted between 2016-2019, 1,280 (33.0%) were admitted via the ER. Patients admitted via the ER were more likely to be in the lowest median income category (p < 0.001), on Medicaid insurance (p = 0.008), or in the South (p < 0.001) than patients admitted otherwise. There was increased severity and increased rates of intracranial hemorrhage (ICH) in patients admitted via the ER (p < 0.001). Finally, there were increasing trends in ER admission and ICH throughout the years. ER admission of pediatric AVM patients with ICH is increasing and is associated with a distinct socioeconomic profile and increased healthcare resource utilization. These findings may reflect decreased access to more advanced diagnostic modalities, primary care, and other important resources. Identifying populations with barriers to care is likely an important component to policy aimed at decreasing the risk of severe disease presentation.

1133 Biologically Effective Dose and Prediction of Obliteration of Arteriovenous Malformations in Pediatric Patients Treated by Gamma Knife Radiosurgery

INTRODUCTION: Stereotactic radiosurgery (SRS) represents an effective treatment for pediatric arteriovenous malformations (AVMs). Biologic effective dose (BED) is recognized as a predictive variable for outcomes in the adult population, but its role has never been studied in pediatric outcomes. METHODS: Retrospective data for = 18 years old patients treated with single-session SRS for AVM was collected from 1989 – 2019. BED calculations were performed using an a/b ratio of 2.47. Kaplan-Meier analysis was used to evaluate obliteration, new hemorrhage, and radiation-induced changes (RIC). Cox-regression analysis was used for obliteration prediction using two models (margin dose versus BED). RESULTS: One-hundred-ninety-seven patients [median age = 13.1 years, Interquartile range (IQR) = 5.2] were included; 72.6% presented initially with spontaneous hemorrhage. A median margin dose of 22 Gy (IQ = 4.0) with a median BED of 183.2Gy (IQR = 70.54) was used to treat AVMs with a median volume of 2.8 cm3 (IQR = 2.9). Following SRS, obliteration was confirmed in 115 patients (58.4%) using MRI and angiography at a median follow-up of 2.85 years (IQR = 2.26). The cumulative obliteration probability was 43.6% (95% CI = 36.1-50.3), 60.5% (95% CI+=2.2-67.4), 66.0% (95% CI= 56.0-73.7) at 3, 5 and 10 years respectively. In multivariate analysis, a BED &gt;180 Gy [HR = 2.11, 95% CI=1.30-3.40, p = 0.002] in model 1, and a margin dose &gt;20 Gy [HR = 1.90, 95% CI = 1.15-3.13, p = 0.019] in model 2, were associated with obliteration. An AVM nidus volume &gt;4 cm3 was associated with lower obliteration rates in both models. The probability of symptomatic RIC at 10 years was 8.6% (95% CI = 3.5-13.4). Neither BED nor margin dose were associated with RIC occurrence, with the only predictive factor being deep AVM location [HR = 3, 95% CI = 1-9.1, p = 0.048]. CONCLUSIONS: This study confirms BED as a predictor for pediatric AVM obliteration. Optimization of BED in pediatric AVM SRS planning may improve cumulative obliteration rates.

Long-term outcomes of deep pediatric arteriovenous malformations.

Multimodality treatment has been shown to be the optimal management strategy for pediatric arteriovenous malformations (AVMs). Deep AVMs represent a subset of AVMs for which optimal management may be achieved with a combination of radiosurgery and highly selective embolization, in the absence of compelling features requiring operative intervention. The objective of this study was to identify predictors of good functional outcomes in pediatric patients with deep AVMs. A retrospective cohort study of the outcomes of 79 patients with deep AVMs from January 1988 through December 2021 was performed. Deep AVMs were defined as those with the majority of the nidus centered in the basal ganglia, thalamus, or brainstem. Collected data included patient demographics and presenting symptoms, presenting modified Rankin Scale (mRS) score, radiographic findings and outcomes, management strategy, complications, and clinical outcomes as indicated by follow-up mRS score. A good outcome was defined as a follow-up mRS score ≤ 2, while a poor outcome was defined as a follow-up mRS score ≥ 3. Statistical analysis was performed to identify factors associated with functional outcomes. With a mean follow-up duration of 85.6 months, there was a 72.2% angiographic obliteration rate, with 75.9% of patients having a good clinical outcome (mRS score ≤ 2). Presenting symptoms and radiographic characteristics were not significantly associated with long-term functional outcomes. There was a significantly higher rate of posttreatment hemorrhage in patients with a poor versus good outcome (11.8% vs 0%, p = 0.010). On multivariate logistic regression analysis, poor long-term functional outcome was only associated with poor presenting mRS score (p = 0.002). Satisfactory angiographic obliteration rates and good long-term functional outcomes can be achieved for deep AVMs, with stereotactic radiosurgery as the cornerstone of multimodality treatment.

Biologically Effective Dose and Prediction of Obliteration of Arteriovenous Malformations in Pediatric Patients Treated by Gamma Knife Radiosurgery.

Stereotactic radiosurgery (SRS) represents an effective treatment for pediatric arteriovenous malformations (AVMs). Biological effective dose (BED) has shown promising results in 2 previous studies as a predictive variable for outcomes in adults, but its role has never been studied in pediatric outcomes. Retrospective data for patients 18 years or younger treated with a single-session SRS for AVMs were collected from 1989 to 2019. BED calculations were performed using an α/β ratio of 2.47. Kaplan-Meier analysis was used to evaluate obliteration, new hemorrhage, and radiation-induced changes (RIC). Cox-regression analysis was used for obliteration prediction using 2 models (margin dose vs BED). One hundred ninety-seven patients (median age = 13.1 years, IQR = 5.2) were included; 72.6% (143/197) of them presented initially with spontaneous hemorrhage. A median margin dose of 22 Gy (IQR = 4.0) with a median BED of 183.2 Gy (IQR = 70.54) was used to treat AVM with a median volume of 2.8 cm 3 (IQR = 2.9). After SRS, obliteration was confirmed in 115/197 patients (58.4%) using magnetic resonance imaging and angiography at a median follow-up of 2.85 years (IQR = 2.26). The cumulative obliteration probability was 43.6% (95% CI = 36.1-50.3), 60.5% (95% CI+ = 2.2-67.4), and 66.0% (95% CI = 56.0-73.7) at 3, 5, and 10 years, respectively. In Cox multivariate analysis, a BED >180 Gy (hazard ratio [HR] = 2.11, 95% CI = 1.30-3.40, P = .002) in model 1 and a margin dose >20 Gy (HR = 1.90, 95% CI = 1.15-3.13, P = .019) in model 2 were associated with obliteration. An AVM nidus volume >4 cm 3 was associated with lower obliteration rates in both models. The probability of symptomatic RIC at 10 years was 8.6% (95% CI = 3.5-13.4). Neither BED nor margin dose was associated with RIC occurrence, with the only predictive factor being deep AVM location (HR = 3, 95% CI = 1-9.1, P = .048). This study confirms BED as a predictor for pediatric AVM obliteration. Optimization of BED in pediatric AVM SRS planning may improve cumulative obliteration rates.

Recurrence of pediatric cerebral arteriovenous malformation after obliteration by radiosurgery: a case report

The rupture of a cerebral arteriovenous malformation is the most common cause of cerebral hemorrhage in children, with recurrence rates reported to be higher than that in adults. Herein, we present the case of a 4-year-old child who initially demonstrated obliteration of a ruptured brain arteriovenous malformation after initial Gamma Knife radiosurgery, but subsequently experienced delayed recurrence, ultimately necessitating a second Gamma Knife radiosurgery procedure. By reviewing this case, we aim to explore considerations regarding the recurrence, treatment, and follow-up strategies for pediatric arteriovenous malformations.

Evolution of clinical and translational advances in the management of pediatric arteriovenous malformations.

Arteriovenous malformations (AVMs) represent one of the most challenging diagnoses in pediatric neurosurgery. Until recently, the majority of AVMs was only identified after hemorrhage and primarily treated with surgery. However, recent advances in a wide range of fields-imaging, surgery, interventional radiology, radiation therapy, and molecular biology-have profoundly advanced the understanding and therapy of these complex lesions. Here we review the progress made in pediatric AVMs with a specific focus on innovations relevant to clinical care.

Curative embolization of ruptured pediatric cerebral arteriovenous malformations

Embolization with the intention to cure has not been well studied in ruptured arteriovenous malformations (AVMs). Furthermore, the role of primary curative embolization of pediatric AVMs is uncertain. Hence, we aimed to characterize the safety and efficacy of curative embolization of ruptured pediatric AVMs and assess predictors of obliteration and complications. A retrospective analysis of all pediatric (≤18 years) patients who underwent curative embolization of ruptured AVMs was conducted in two institutions between 2010 and 2022. The efficacy (complete angiographic obliteration after the last embolization session), recurrence (radiological recurrence of the lesion after confirmed obliteration in follow-up imaging), and safety (procedure-related complications and mortality) of the procedure were evaluated. Sixty-eight patients (38 females; mean age 12.4±3.4 years) underwent a total of 109 embolization sessions. Median follow-up time was 18 months after embolization (ranged from 2 to 47 months). Complete angiographic obliteration was achieved in 42 patients (62%). In 30 patients (44%) the AVM was occluded with a single embolization session. Recurrence of a totally embolized lesion occurred in 9 patients (13%). Thirteen complications (11.9% of procedures) were observed, and no deaths were reported. A nidus size >2cm was the only independent predictor of complete obliteration (OR = 0.16; 95% CI 0.03 - 0.77; p=0.030). Embolization of pediatric ruptured AVMs with curative intent can achieve acceptable obliteration rates. However, recurrence after complete obliteration and procedure-related complications of curative embolization of these lesions cannot be ignored. Ruptured AVMs ≤2cm are adequate to achieve complete obliteration with curative endovascular management.

196 Increased Hemorrhage Risk With Brain AVM-Associated Aneurysms in Children

INTRODUCTION: Brain arteriovenous malformations (AVMs) represent a major cause of intracranial hemorrhage with pediatric patients at greater lifetime risk of rupture compared to their adult counterparts. These AVMs can be associated with aneurysms that are either arterial or intranidal. The significance of AVM-associated aneurysms in the pediatric population remains poorly understood due to their rare nature and spare reporting. METHODS: We reviewed a prospectively maintained database of pediatric brain AVMs from 1998 to 2021 at the University of California, San Francisco. Inclusion criteria included patients with age ≤ 18 at time of presentation with angiographically-proven AVM. RESULTS: Of 231 patients with AVMs, 24 patients harbored 35 arterial aneurysms, and 35 patients harbored 38 intranidal aneurysms. Compared to AVMs without aneurysms with a mean nidus size of 3.02 ± 1.74 cm, AVMs with intranidal aneurysms had a significantly smaller mean nidus size at 2.13 ± 1.12 cm (p = 0.004). AVMs with intranidal aneurysms had a higher proportion of being ruptured on presentation compared to AVMs without aneurysms (94% vs. 59%, p &lt; 0.001). AVMs with intranidal and arterial aneurysms also underwent higher proportions of surgical resection (92% and 80% vs. 59%, p = 0.001) and embolization (37% and 50% vs. 25%, p = 0.022) with higher rates of nidus obliteration (91% and 79% vs. 65%, p = 0.005). In those that were not obliterated, AVMs with intranidal and arterial aneurysms have higher annual hemorrhage risks (10.2% and 7.4% vs. 1.6%) after patient presentation. Patients who underwent a hemorrhage event after presentation had a higher proportion of worsened clinical status compared to presentation (38% vs. 5.6%, p &lt; 0.001). CONCLUSIONS: A higher proportion of AVMs with associated aneurysms present with hemorrhage and are more likely to undergo additional hemorrhage events when incompletely treated compared to AVMs without aneurysms.

Abstract Number ‐ 210: Curative Embolization of Ruptured Pediatric Cerebral Arteriovenous Malformations

Introduction The incidence of ruptured cerebral arteriovenous malformations (AVMs) has increased as a consequence of the publication of the ARUBA trial. In the setting of ruptured AVMs, target embolization of high‐risk features can be considered to decrease the risk for recurrent hemorrhage. However, embolization with the intention to cure has not been well studied in ruptured AVMs. Furthermore, the role of primary curative embolization of pediatric AVMs is uncertain. Hence, we aimed to characterize the safety and efficacy of curative embolization for ruptured AVMs in pediatric patients. Methods Between 2010 and 2022, a retrospective analysis of all pediatric (≤18 years) patients who underwent curative embolization for ruptured AVMs was conducted in two institutions. Demographic data, clinical presentation, Spetzler‐Martin (SM) grade, associated high‐risk vascular structures, and procedural characteristics were retrieved. The safety (intraprocedural complications and mortality) and efficacy (complete angiographic obliteration after the last embolization session) were evaluated. Results Sixty‐eight patients (38 females; mean age 12.4 ± 3.4 years) underwent a total of 109 embolization sessions. The most frequent clinical presentation was headache (79%). There were 15 (22%) SM grade I lesions, 34 (51%) grade II, 14 (21%) grade III, and 4 (6%) grade IV. In 21 patients, twenty‐three high‐risk structures were observed (3 prenidal aneurysms, 12 intranidal aneurysms, 3 venous aneurysms, 2 varicose veins, 3 arteriovenous fistulae). Decompressive craniectomy with intracerebral hemorrhage evacuation was performed in 15 patients (22%). The mean number of sessions per patient was 1.6 (range 1 to 6) and n‐butyl cyanoacrylate was the most used embolic agent (30%). The transarterial approach was the most common (91%). The mean volume of embolic agents in each patient was 2.1 ml (range 0.1 to 6 ml). Seventeen intraprocedural complications (16% of procedures) were observed and no deaths were reported. In patients with high‐risk structures the rate of intraprocedural complications was 24%. The most common complication was microcatheter‐related vessel perforation (7%). Complete angiographic obliteration was achieved in 42 patients (62%). In 30 patients (44%) the AVM was occluded with a single embolization session. The rate of complete obliteration in patients with high‐risk structures was 62%. Conclusions Curative embolization of ruptured pediatric AVMs shows a high rate of intraprocedural complications, especially when high‐risk associated vascular structures are present. In addition, acceptable complete obliteration rates were found. Appropriate long‐term follow‐up in prospective studies tailored to the pediatric population are required to determine the best therapeutic approach.

Abstract Number ‐ 197: A Single‐Center, 23‐Year Experience with the MAGIC Catheter for Pediatric AVM

Introduction The MAGIC Catheter (Balt, Montmorency, France) is a commonly used flow‐directed microcatheter for neuro‐interventions. Despite the MAGIC catheter not having FDA approval for use in pediatric and neonatal populations, our institution has used this catheter off‐label for numerous cases of pediatric arteriovenous malformation (AVM), vein of Galen malformation (VOGM), dural arteriovenous fistula (dAVF), and pial AVF (pAVF). Herein, we outline our practice’s experience with the MAGIC catheter for pediatrics. Methods We reviewed our institutional, quality‐control database for all cases of pediatric, vascular malformation that utilized the MAGIC catheter since its original use in pediatrics at our practice (March 1999) and July 2022. We describe the disease and demographic characteristics of this cohort, frequency of MAGIC catheter use, adjunct supplies, complications, smallest vessels catheterized, and clinical outcomes. Results Over the review period, 99 pediatric patients with AVM(45), VOGM(49), dAVF(3), and pAVF(2) were identified for detailed review. This cohort has collectively undergone 194 procedures. The average age at first procedure with the MAGIC catheter was 4.42 years with a wide variation (SD: 4.56; Range: 0–17.64). The majority of cases using the MAGIC catheter were cerebral angiograms with embolization (190 – 97.9%), though occasionally it was employed for angiography alone (4 – 2.1%). A 4‐Fr Berenstein Catheter was the most common adjunct catheter used during the study period (156/194; 80.4%), though the 5‐Fr Envoy appeared often as well (30/194; 15.5%). Every embolization in the series led to interval‐decrease or cure of the malformation, though five intraprocedural complications were noted in the form of transient decrease neuromonitoring evoked potentials, epidural hematoma due to vessel perforation, and three cases of vessel perforation without long‐term consequence. Periprocedural complications occurred in one patient involving an intraventricular hemorrhage requiring a ventriculoperitoneal shunt. The most common liquid embolic agent used with the MAGIC catheter was nBCA (179/190; 94.2%) with occasional use of Onyx 18, Fibered Coils, Surgi‐Flo, STS, and Ethanol. Of the 67 patients who had a follow‐up available for review, 30 (44.8%) are neurologically intact and clinically well, 19(28.4%) are clinically well with mild symptoms (mild autism spectrum disorder, mild hemiparesis, headaches, mild weakness, post‐hemorrhage/stroke excellent recovery), 9 (13.4%)have experienced moderate to severe symptoms (limb weakness, cranial neuropathies, cognitive delay/deficit, inability to ambulate, seizures), 3 (4.5%) have passed away, and 6 (9.0%) have been lost to follow‐up. Selective catheterization of small vessels was performed among the anterior choroidal, thalamoperforator, posterior choroidal, middle meningeal arteries and superior cerebellar, posterior cerebral, and deep external/internal carotid artery branches, and many others by the MAGIC microcatheter for contrast injection or delivery of embolic agents. Conclusions Flow‐directed microcatheters are a quintessential tool used in the endovascular treatment of cerebrovascular diseases, but few have regulatory approval for use in pediatric populations. The off‐label use of the MAGIC microcatheter has been shown to be safe and effective in pediatric embolization procedures. However, there still remains a technology gap in the development of flow‐directed catheters specifically designed and proportioned for use in pediatric patients.

External validation of the R2eD AVM scoring system to assess rupture risk in pediatric AVM patients.

The assessment of hemorrhagic risk is of central importance in the management of pediatric brain arteriovenous malformations (AVMs). A recently published scoring system, the R2eD AVM (race, exclusive deep location or not, AVM size < 3 or ≥ 3, venous drainage exclusively deep or not, and monoarterial feeding or >1 arterial feeders) considers patient race and AVM location, size, venous drainage, and arterial supply and was successfully externally validated for use in adults to predict the risk of AVM hemorrhagic presentation. In this study the authors sought to externally validate the R2eD AVM score for prediction of hemorrhagic risk in the pediatric AVM population. A pediatric database at Boston Children's Hospital was retrospectively reviewed for all patients with a diagnosis of intracranial AVM. Exclusion criteria included age > 21 years, multiple AVMs, and incomplete clinical/radiographic data. Demographic data and R2eD AVM score calculations were collected for all patients. Univariate binary logistic regression and multivariate stepwise backward elimination models were used to determine factors associated with hemorrhagic presentation. A total of 212 AVMs were identified in 212 patients with vascular anomalies from 1995 to 2021, and 144 patients met the inclusion criteria (74 [51.4%] male, 111 [77.1%] White), of whom 87 (60.4%) patients presented with rupture and 122 (84.7%) underwent resection. The mean age at surgery was 12 years (range 3 months to 20 years). The R2eD AVM scoring system was applied to each patient. The score components of size < 3 cm and exclusive deep venous drainage were significantly associated with rupture risk (p < 0.05). The complete model for the R2eD AVM score had an area under the curve of 0.671 (95% CI 0.586-0.757). This study demonstrated poor external validity of the R2eD AVM score in predicting pediatric AVM rupture risk. The results suggest that future studies are warranted to determine a better scoring method to capture pediatric rupture risk, given the significant differences in clinical presentation in pediatric compared with adult AVM patients.

Clinical features and outcome in pediatric arteriovenous malformation: institutional multimodality treatment.

Intracranial arteriovenous-malformation (AVM) is a relatively rare condition in pediatrics, yet is a major cause of spontaneous intracranial hemorrhage with a risk of fatal hemorrhage reported to be between 4 and 29%. Little is known about vessel morphology and optimum treatment modalities including multimodality combination therapy and prognosis in children. A retrospective review of all children presenting to our institution from 2006 to 2020 that had an AVM was undertaken. A total of 50 children were identified with median age of 11 (range 1-16) years. The mean follow-up was 7.6years. Forty-one children presented as an emergency and of those, 40 had hemorrhage identified on initial brain imaging. The average nidus size was 25mm, drainage was superficial in 51% of cases, and located in eloquent cortex in 56%. The supplemental Spetzler-Martin grading indicated 78% (39/50) were grade 4 and above (moderate to high risk). Primary treatment modalities included embolization in 50% (25) or SRS in 30% (15) and surgery in 20% (10).The AVM was obliterated on follow-up DSA in 66% children. Three children had post-treatment hemorrhage, two related to embolization and one the day following SRS, giving a re-bleed rate of 6%. The GOSE was available for 32 children at long term follow and 94% had a good outcome (GOSE 5-8). Two children died due to acute hemorrhage (4%). The majority of children with AVM present with hemorrhage. The rebleed rate during definitive treatment is low at 6% over the study period. The selective use of the 3 modalities of treatment has significantly reduced mortality and severe disability.

Long-Term Outcomes after Endovascular Oblitraion of Pediatric Arteriovenous Malformation : A Multi-Center Analysis

Long-Term Outcomes after Endovascular Oblitraion of Pediatric Arteriovenous Malformation : A Multi-Center Analysis

New aneurysm formation and regrowth associated with rebleeding of residual pediatric ruptured arteriovenous malformation: patient series.

If complete obliteration of ruptured pediatric arteriovenous malformation (AVM) cannot be achieved, the appropriate follow-up duration and predictors of rebleeding remain unknown. Pediatric patients with ruptured AVMs admitted to the authors' hospital within the past 30 years were evaluated. Rebleeding was confirmed in two patients. The first patient was a 5-year-old boy who experienced right thalamic hemorrhage. AVM was found in the bilateral thalamus and treated with stereotactic radiosurgery (SRS). New aneurysm formation and residual AVM regrowth were confirmed 21 years after the SRS. Eight months later, rebleeding occurred. The second patient was a 5-year-old boy who underwent removal of a left cerebellar hemorrhage and AVM. The residual AVM was treated with SRS. Residual AVM regrowth was detected at 6 years 7 months after SRS. Five months later, new aneurysm formation was confirmed. Two additional days later, rebleeding occurred. New aneurysm formation and residual AVM regrowth may predict rebleeding and can occur >20 years after the initial rupture and treatment. If AVM obliteration is not achieved, long-term follow-up is needed, even in adulthood, with attention to new aneurysm formation and residual AVM regrowth. Further treatment is recommended if these findings are confirmed.

Delayed recurrence of pediatric arteriovenous malformations after radiologically confirmed obliteration.

Arteriovenous malformations (AVMs) are a major cause of intracerebral hemorrhage in children, resulting in significant morbidity and mortality. Moreover, the rate of AVM recurrence in children is significantly higher than in adults. The aim of this study was to define the risk of delayed pediatric AVM (pAVM) recurrence following confirmed radiological obliteration. Further understanding of this risk could inform the role of long-term radiological surveillance. The authors conducted a retrospective review of ruptured and unruptured pAVM cases treated at a single tertiary care referral center between 1994 and 2019. Demographics, clinical characteristics, treatment modalities, and AVM recurrence were analyzed. A total of 102 pediatric patients with intracranial AVMs, including 52 (51%) ruptured cases, were identified. The mean patient age at presentation was 11.2 ± 4.4 years, and 51 (50%) patients were female. The mean nidus size was 2.66 ± 1.44 cm. The most common Spetzler-Martin grades were III (32%) and II (31%). Stereotactic radiosurgery was performed in 69.6% of patients. AVM obliteration was radiologically confirmed in 68 (72.3%) of 94 patients with follow-up imaging, on angiography in 50 (73.5%) patients and on magnetic resonance imaging in 18 (26.5%). AVM recurrence was identified in 1 (2.3%) of 43 patients with long-term surveillance imaging over a mean follow-up of 54.7 ± 38.9 months (range 2-153 months). This recurrence was identified in a boy who had presented with a ruptured AVM and had been surgically treated at 5 years of age. The AVM recurred 54 months after confirmed obliteration on surveillance digital subtraction angiography. Two other cases of presumed AVM recurrence following resection in young children were excluded from recurrence analysis because of incomplete sets of imaging available for review. AVM recurrence following confirmed obliteration on imaging is a rare phenomenon, though it occurs more frequently in the pediatric population. Regular long-term follow-up with dedicated surveillance angiography is recommended even after obliteration following resection.

Return of the lesion: a meta-analysis of 1134 angiographically cured pediatric arteriovenous malformations.

Brain arteriovenous malformations (AVMs) carry a risk of rupture and subsequent morbidity or mortality unless fully treated. AVMs in pediatric patients are known to occasionally recur after obliteration. The objective of this study was to characterize the risk of AVM recurrence following angiographically confirmed obliteration in children. Consecutive pediatric AVMs treated at a single center were identified from a prospective database. Patients with angiographically confirmed AVM obliteration following treatment were included in this study. Associations between AVM recurrence and patient or procedural factors were characterized using the two-tailed Fisher exact test or Mann-Whitney U-test. A literature search was conducted using PubMed, Scopus, Embase, and the Clarivate Web of Science with defined search criteria, and eligible studies were included alongside this study cohort in a meta-analysis. Rates of AVM recurrence following obliteration were pooled across studies with a random-effects model and reported with 95% confidence intervals (CIs). Recurrence after angiographic confirmation of AVM obliteration was observed in 10.4% (7/67) of pediatric AVMs treated at the authors' center. Patients with recurrent AVMs were significantly younger than those without recurrence (p = 0.002). In the meta-analysis, which included 1134 patients across 24 studies, the rate of recurrence was 4.8% (95% CI 3.0%-6.7%). The rate of AVM recurrence following radiosurgery was 0.7% (95% CI 0%-1.6%), which was significantly lower than the 8.5% rate (95% CI 5.0%-12.0%) following microsurgery. Recurrence of obliterated brain AVMs is common in children. Recurrence is more common in young children and following microsurgery.