Cross-sectional study of a United Kingdom cohort of neonatal vein of galen malformation

Cerebrovascular Anomalies in the Fetus

Four distinct vascular anomalies can be seen to affect the brain on fetal imaging: vein of Galen malformations, nongalenic arteriovenous pial fistulas, dural sinus malformations, and intracranial venous malformations. These congenital disorders affect the arteries and veins of the developing brain and are rarely seen beyond the neonatal stage. The 4 fetal cerebrovascular anomalies are associated with quite disparate natural histories and prognoses. MRI plays a pivotal role in the evaluation of fetuses with these conditions because of its ability to definitively establish the diagnosis, to detect subtle parenchymal injuries, to delineate the course of abnormal vessels in detail and to some extent the nature of vascular flow, and to identify ischemic, thrombotic, and hemorrhagic complications. Recently, an investigational transuterine embolization procedure targeted at treating fetuses with vein of Galen malformations who are at high risk for neonatal decompensation has emerged as a promising alternative to expectant management and postnatal embolization, with imaging being used to identify suitable patients for the intervention and in preprocedural planning. This manuscript reviews the essential imaging and clinical features of these 4 fetal neurovascular anomalies and underscores the practical aspects related to counseling, prognosis, and the multidisciplinary management of these entities.

Cerebral Doppler imaging in neonates: A guide for clinical application and diagnosis

Cranial ultrasound reliably diagnoses many neonatal brain disorders. Adding Doppler imaging expands the spectrum by providing information on the status of the vasculature and haemodynamics that may guide further diagnostic and clinical management. Doppler imaging may identify neonates with congenital or acquired vascular abnormalities such as perinatal stroke, sinuvenous thrombosis, vein of Galen malformation, dural sinus malformation, sinus pericranii, and developmental venous anomaly. These entities may need further investigation with complementary imaging modalities such as magnetic resonance imaging and magnetic resonance angiography, or conventional angiography. This review aims to help clinicians to improve their Doppler sonography knowledge and skills in order to use this helpful tool in neonates with neurological symptoms or suspected cerebral vascular abnormalities admitted to the neonatal intensive care unit.

Overcoming roadblocks in clinical innovation via high fidelity simulation: use of a phantom simulator to achieve FDA and IRB approval of a clinical trial of fetal embolization of vein of Galen malformations

BACKGROUND

Vein of Galen malformation (VOGM) is a rare, life-threatening vascular malformation in neonates and is treated with embolization. However, even at the most experienced centers, patients face high mortality and morbidity. In utero treatment options have been limited by lack of animal models or simulations.

OBJECTIVE

To create a novel ultrasound phantom simulator for a preclinical feasibility study of in utero fetal intervention for VOGM.

METHODS

Novel phantoms were designed and built in two configurations of spherical and windsock shape from cryogel material to mimic the salient vasculature of the fetal VOGM, based on real-patient fetal MR imaging dimensions. Critical anatomy was realistically mimicked within this model and transtorcular ultrasound-guided coil deployment was simulated. Each phantom model was assessed before and after treatment to evaluate coil mass deposition within the target.

RESULTS

The two phantoms underwent pretreatment T2-weighted MR imaging assessment, ultrasound-guided embolization, post-treatment MR and fluoroscopic imaging, and visual inspection of the sliced phantoms for target embolization verification. Postoperative MR scans confirmed realistic compact deposition of the coil masses within the central cavity. Phantom embolization results were submitted as part of the institutional review board and US Food and Drug Administration investigative device exemption approval for a first-in-humans clinical trial of fetal intervention for VOGM.

CONCLUSIONS

A phantom simulator for fetal intervention of VOGM produces lifelike results during trial interventions, removing obstacles to feasibility and safety evaluations, typically precluded by non-availability of appropriate animal models. The study provides a proof of concept for potentially wider applications of medical simulation to enable novel procedural advancements in neurointerventions.

Mutation of key signaling regulators of cerebrovascular development in vein of Galen malformations

To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes. We found the Ras suppressor p120 RasGAP (RASA1) harbored a genome-wide significant burden of loss-of-function de novo variants (2042.5-fold, p = 4.79 x 10-7). Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 (EPHB4) (17.5-fold, p = 1.22 x 10-5), which cooperates with p120 RasGAP to regulate vascular development. Additional probands had damaging variants in ACVRL1, NOTCH1, ITGB1, and PTPN11. ACVRL1 variants were also identified in a multi-generational VOGM pedigree. Integrative genomic analysis defined developing endothelial cells as a likely spatio-temporal locus of VOGM pathophysiology. Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant (Phe867Leu) exhibited disrupted developmental angiogenesis and impaired hierarchical development of arterial-capillary-venous networks, but only in the presence of a "second-hit" allele. These results illuminate human arterio-venous development and VOGM pathobiology and have implications for patients and their families.

Aortic Steal Correlates with Acute Organ Dysfunction and Short-Term Outcomes in Neonates with Vein of Galen Malformation

INTRODUCTION

Vein of Galen aneurysmal malformation (VGAM) is a rare, congenital cerebrovascular malformation with high morbidity and mortality. Parameters to foresee clinical progression and allow individualized parent counseling are lacking. The aim of this study was to evaluate aortic steal measured by Doppler ultrasound as a prognostic parameter in these neonates.

METHODS

A retrospective monocentric analysis of cardiac ultrasound exams before embolization in neonates with VGAM was conducted. Percentage of aortic steal measured by time-averaged maximum velocity above and below the zero flow baseline by pulsed Doppler ultrasound at the preductal aortic isthmus was calculated. Association of aortic steal with parameters of acute organ dysfunction (Bicêtre neonatal evaluation score [BNES], neonatal multiple organ dysfunction score [NeoMODS]) and mortality and determination of correlation between aortic steal and cerebral damage on initial and follow-up cerebral magnetic resonance imaging (cMRI) were evaluated.

RESULTS

Twelve neonates were included, of which 3 died. Per 10 percentage point increase of aortic steal, BNES decreased by 1.64 (95% confidence interval [CI]: 1.28-2.0) points and the maximum observed NeoMODS increased by 1.25 (CI: 0.94-1.57) points. The odds for mortality increased by 2.3 (CI: 1.14-13.67) per 10 percentage point increase of aortic steal. There was a correlation between aortic steal and cerebral damage at baseline (white matter ρ [rho] = 0.34, gray matter ρ = 0.81) and follow-up (white matter ρ = 0.80, gray matter ρ = 0.72).

CONCLUSION

The degree of aortic steal in neonates with VGAM was highly associated with the severity of organ dysfunction, disease progression on cMRI, and mortality.

Vein of Galen aneurysmal malformation in newborns: a retrospective study to describe a paradigm of treatment and identify risk factors of adverse outcome in a referral center

Background

Vein of Galen aneurysmal malformation (VGAM) is a rare cerebral vascular malformation associated with significant morbidity and mortality. Newborns with VGAM without adequate treatment may develop rapidly deteriorating high output heart failure (HOHF) and are at risk for severe neurological outcomes.

Objective

To describe the clinical course and management of newborns with VGAM, and identify which echocardiographic and neuroradiologic factors may be associated with severe heart failure at birth and adverse short term outcomes.

Methods

This is a single center retrospective cohort study including all consecutive newborns with VGAM admitted to Gaslini Children's Hospital between 2009 and 2022. We reviewed clinical data, intensive care support, fetal and neonatal cardiologic and neuroradiologic findings and we studied the association with severe HOHF, endovascular complications and death.

Results

Out of 40 newborns, 17 (42.5%) developed severe HOHF requiring early endovascular procedures. Medical treatment was focused on the main components of HOHF by providing inotropic support and peripheral vasodilation. Pulmonary vasodilators were avoided to reduce the negative effects of pulmonary overflow and prevent vascular remodeling. Reduction of the obligatory left to right shunt through the VGAM was possible only through endovascular treatment. Fetal cardiothoracic ratio was significantly associated with severe HOHF at birth and death. Cardiologic parameters of right ventricular overload, pulmonary hypertension and systemic steal were the leading findings associated with haemodynamic compromise at birth. The mediolateral diameter of the straight or falcine sinus at its shortest section (SS-MD), and arterial pseudofeeders were significantly associated with severe HOHF at birth in prenatal and postnatal assessments. None of the postnatal echocardiographic and MRI variables, nor a higher inotropic support were associated with major periprocedural complications or death. Mortality was due to palliation for congenital severe brain damage (4/40, 10%), or major periprocedural complications (3/40, 7.5%). None of the patients died due to HOHF and multiorgan failure. Overall survival at discharge was 82.5% (33/40).

Conclusions

The complexity of neonatal VGAM pathophysiology requires a multidisciplinary approach, specialized intensive care management, and early endovascular treatment to reduce mortality and optimize clinical outcomes. Cardiologic and neuroradiologic parameters are key to define risk stratification and treatment strategies.

Pulmonary Hypertension in Infants and Children with Vein of Galen Malformation and Association with Clinical Outcomes

OBJECTIVE

To assess the extent and resolution of pulmonary hypertension (PH), cardiovascular factors, and echocardiographic findings associated with mortality in infants and children with vein of Galen malformation (VOGM).

STUDY DESIGN

We performed a retrospective review of 49 consecutive children with VOGM admitted to Boston Children's Hospital from 2007 to 2020. Patient characteristics, echocardiographic data, and hospital course were analyzed for 2 cohorts based on age at presentation to Boston Children's Hospital: group 1 (age ≤60 days) or group 2 (age >60 days).

RESULTS

Overall hospital survival was 35 of 49 (71.4%); 13 of 26 (50%) in group 1 and 22 of 23 (96%) in group 2 (P < .001). High-output PH (P = .01), cardiomegaly (P = .011), intubation (P = .019), and dopamine use (P = .01) were significantly more common in group 1 than group 2. Among patients in group 1, congestive heart failure (P = .015), intubation (P < .001), use of inhaled nitric oxide (P = .015) or prostaglandin E1 (P = .030), suprasystemic PH (P = .003), and right-sided dilation were significantly associated with mortality; in contrast, left ventricular volume and function, structural congenital heart disease, and supraventricular tachycardia were not associated. Inhaled nitric oxide achieved no clinical benefit in 9 of 11 treated patients. Resolution of PH was associated with overall survival (P < .001).

CONCLUSIONS

VOGM remains associated with substantial mortality among infants presenting at ≤60 days of life owing to factors associated with high output PH. Resolution of PH is an indicator associated with survival and a surrogate end point for benchmarking outcomes.

Pediatric Interventional Neuroradiology

Pediatric neurovascular disorders can lead to substantial mortality and morbidity if not diagnosed early and adequately managed. Children with neurovascular diseases cannot be treated as small adults as the vascular and central nervous system anatomy, physiology, and pathologies in children differ greatly from those of adults. In addition, some neurovascular pathologies are seen exclusively in children such as aneurysmal malformation of the vein of Galen, pial fistulas, and dural fistulas in the context of dural sinus disease. In this review, we aim to present an overview of the common pediatric neurovascular diseases along with their endovascular management.

Doppler Ultrasound Flow Reversal in the Superior Sagittal Sinus to Detect Cerebral Venous Congestion in Vein of Galen Malformation

BACKGROUND AND PURPOSE

Vein of Galen malformation is a rare congenital cerebrovascular malformation. In affected patients, increased cerebral venous pressure constitutes an important etiologic factor for the development of brain parenchymal damage. The aim of this study was to investigate the potential of serial cerebral venous Doppler measurements to detect and monitor increased cerebral venous pressure.

MATERIALS AND METHODS

This was a retrospective monocentric analysis of ultrasound examinations within the first 9 months of life in patients with vein of Galen malformation admitted at <28 days of life. Categorization of perfusion waveforms in the superficial cerebral sinus and veins into 6 patterns was based on antero- and retrograde flow components. We performed an analysis of flow profiles across time and correlation with disease severity, clinical interventions, and congestion damage on cerebral MR imaging.

RESULTS

The study included 44 Doppler ultrasound examinations of the superior sagittal sinus and 36 examinations of the cortical veins from 7 patients. Doppler flow profiles before interventional therapy correlated with disease severity determined by the Bicêtre Neonatal Evaluation Score (Spearman ρ = -0.97, P = < .001). At this time, 4 of 7 patients (57.1%) showed a retrograde flow component in the superior sagittal sinus, whereas after embolization, none of the 6 treated patients presented with a retrograde flow component. Only patients with a high retrograde flow component (equal or more than one-third retrograde flow, n = 2) showed severe venous congestion damage on cerebral MR imaging.

CONCLUSIONS

Flow profiles in the superficial cerebral sinus and veins appear to be a useful tool to noninvasively detect and monitor cerebral venous congestion in vein of Galen malformation.

Heart Failure Following Sinus Venosus Defect Closure in a Patient With Vein of Galen Malformation

This case concerns an 18-month-old with masked congestive heart failure (CHF) from an unrepaired vein of Galen malformation and superior sinus venosus defect who progressed to severe, refractory CHF following superior sinus venosus defect repair. Partial transvenous coil embolization of a very-high-risk vein of Galen malformation resolved CHF symptoms. (Level of Difficulty: Advanced.).

Genetic dysregulation of an endothelial Ras signaling network in vein of Galen malformations

To elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and severe congenital brain arteriovenous malformation, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes. We found the Ras suppressor p120 RasGAP ( RASA1 ) harbored a genome-wide significant burden of loss-of-function de novo variants (p=4.79×10 ^-7 ). Rare, damaging transmitted variants were enriched in Ephrin receptor-B4 ( EPHB4 ) (p=1.22×10 ^-5 ), which cooperates with p120 RasGAP to limit Ras activation. Other probands had pathogenic variants in ACVRL1 , NOTCH1 , ITGB1 , and PTPN11 . ACVRL1 variants were also identified in a multi-generational VOGM pedigree. Integrative genomics defined developing endothelial cells as a key spatio-temporal locus of VOGM pathophysiology. Mice expressing a VOGM-specific EPHB4 kinase-domain missense variant exhibited constitutive endothelial Ras/ERK/MAPK activation and impaired hierarchical development of angiogenesis-regulated arterial-capillary-venous networks, but only when carrying a "second-hit" allele. These results illuminate human arterio-venous development and VOGM pathobiology and have clinical implications.

The composition of landmark vein of Galen malformation research: the emergence of endovascular treatments

BACKGROUND

Since the advent of endovascular treatment, the long-term prognosis of vein of Galen malformation (VOGM) has markedly improved; however, the nature of research leading to this point is unclear. The objective of this study was to define the composition of VOGM research to date, by means of a bibliometric analysis of the 100 most cited VOGM articles.

METHODS

An electronic search of Elsevier's Scopus database was performed to identify the 100 most cited articles on VOGM screened against predetermined criteria. Data were then compared.

RESULTS

The 100 most cited VOGM articles were published between 1974 and 2017 in 38 unique journals and originated from 16 unique countries. Mean citation count and rate were 59.4 citations and 2.9 citations/year, respectively. The USA (n = 42); Hôpital de Bicêtre, France (n = 15); and Dr. Pierre Lasjaunias (n = 16) were the largest individual country, institutional, and author contributors. Compared to the older articles (published < 2000), key differences for newer articles were statistically higher citation rates (P < 0.01), more authors (P < 0.01), higher proportion of endovascular treatment descriptions (P = 0.01), and more originating from Asia Pacific (P < 0.01).

CONCLUSIONS

From the 100 most cited VOGM articles to date, there has been a noticeable shift from diagnosing VOGM based on the foundational work by Dr. Lasjaunias to understanding how we can model clinical outcomes now that endovascular treatment has become the standard of care. Significant shifts in prognosis are pending, and the current bibliometric data implicate we are on the precipice of more recent works making an impact in the near future.

Outcome of fetal Vein Galen aneurysmal malformations: a systematic review and meta-analysis

OBJECTIVES

To report the outcome of fetuses with a prenatal diagnosis of Vein of Galen (VOG) malformation.

METHODS

PubMed and Embase databases were searched. Random effect meta-analysis of proportions was used to analyze the data. The outcomes explored were prenatal ultrasound findings, mortality, preterm birth (PTB), abnormal neurological outcome, associated findings detected at post-natal brain imaging, need for anticonvulsant therapy, and the rate of children free from neurological impairment. Random effect meta-analysis of proportions were used to analyze the data.

RESULTS

Eleven studies (226 fetuses with a prenatal diagnosis of VOG malformation) were included. All cases were detected during the third trimester of pregnancy. Ventriculomegaly was detected in 31.8% (95% CI 27.6-47.7), cardiomegaly or other ultrasound signs of cardiac compromise in 23.1% (95% CI 14.9-32.5) and hydrops in 7.3% (95% CI 2.8-13.6) of cases. The incidence of IUD, NND, and PND was 1.5% (95% CI 0.2-4.3), 23.8% (95% CI 16.9-31.4), and 24.5% (95% CI 17.6-32.2), respectively, while 12.6% (95% CI 6.0-21.2) of pregnancies were complicated by PTB. Abnormal neurodevelopmental outcome was observed in 36.7% (95% CI 27.9-39.7) of cases, while 60.5% (95% CI 17.0-82.0) of children had abnormal findings on post-natal imaging and only 29.7% (95% CI 23.3-36.5) were free from neurological impairment after birth, although there was a wide heterogeneity in the time at follow-up between the included studies.

CONCLUSION

VOG malformation diagnoses during fetal life is associated with a high incidence of brain damage, cardiac compromise, and abnormal neurodevelopmental outcome after birth.

State of the art of antenatal diagnosis and management of vein of Galen aneurysmal malformations

Vein of Galen aneurysmal malformation (VGAM) is a severe rare vascular anomaly whose prognosis depends on cerebral and cardiac consequences that can be hard to diagnose, let alone predict in utero. We performed an updated review to summarize current research on the genetics, ultrasound and MRI of VGAM that could help in the diagnosis and management of VGAM. Prenatal diagnosis of VGAM has greatly improved in recent years. Ultrasound allows in utero detection of VGAM in most cases now and is the best exam for prenatal cardiac evaluation. Tricuspid insufficiency is the only cardiac feature associated with poor prognosis. Cardiomegaly may indicate a risk of cardiac failure at birth and should prompt discussion of birth in a specialized facility. Ultrasound can identify constituted cerebral lesions, but MRI diagnoses early signs of cerebral hemodynamic changes, notably through the detection of pseudo-feeders. Genetic exploration should be proposed after VGAM diagnosis. Ultrasound and MRI are essential complementary tools for the diagnosis of VGAM, but also for prognostic evaluation, and provide information for the counseling of parents and optimal management of the pregnancy.

Fetal Neurosurgical Interventions for Spinal Malformations, Cerebral Malformations, and Hydrocephalus: Past, Present, and Future

In this article we review the last 40 years of progress in fetal neurosurgery with special attention to current controversies and upcoming challenges in the field. We surveyed the published literature describing prenatal interventions for spinal malformations, cerebral malformations, and hydrocephalus. Even the most mature treatment paradigm, intrauterine repair of myelomeningocele, stands to benefit from advances in imaging and therapeutic modalities to improve patient selection, refine surgical techniques, validate novel biologic therapies, and streamline postoperative patient care. Other conditions under evaluation include congenital cerebral malformations, such as encephalocele, cerebrovascular malformations, and hydrocephalus. We describe cross-cutting needs for advances in fetal neuroimaging, basic disease models and new therapeutic devices to support further progress across various neurosurgical conditions affecting patients during the fetal period.

Brain Injury in Fetuses with Vein of Galen Malformation and Nongalenic Arteriovenous Fistulas: Static Snapshot or a Portent of More?

BACKGROUND AND PURPOSE

Brain injury in fetuses with vein of Galen malformations and nongalenic AVFs is a rare complication whose appearance, course, and prognosis are poorly studied. We sought to characterize the MR imaging features and examine associations with postnatal outcome.

MATERIALS AND METHODS

This was a retrospective analysis of fetal MRIs of subjects with vein of Galen malformation and nongalenic arteriovenous fistulas. Two pediatric neuroradiologists independently reviewed examinations to determine the presence of abnormalities on structural imaging (T1 volumetric interpolated breath-hold examination and T2-HASTE), DWI, and T2*-weighted images; discrepancies were adjudicated by a third reviewer. Radiologic progression of injury was determined by additional fetal or neonatal MRIs. A simple composite score evaluating poor neonatal clinical outcome as either intubation or death by postnatal day 2 was also queried. A body fetal imager evaluated the presence of systemic findings of right heart strain.

RESULTS

Forty-nine fetal MR imaging examinations corresponding to 31 subjects (27 vein of Galen malformations and 4 nongalenic AVF cases) were analyzed. Injury was observed in 8 subjects (26%) with 14 fetal examinations; the mean gestational age at identification of injury was 32.2 (SD 4.9) weeks. Structural abnormalities were present in all subjects with injury; restricted diffusion, in 5/7 subjects with available data; and T2* abnormalities, in all subjects with available data (n = 7). Radiologic progression was documented in all cases with follow-up imaging (n = 7). All subjects with fetal brain injury had a poor neonatal clinical outcome.

CONCLUSIONS

Brain injury in fetuses with vein of Galen malformation and nongalenic AVFs shows a combination of structural abnormalities, restricted diffusion, and blooming on T2* images. Injury appears to portend a poor prognosis, with relentless progression and a likely association with adverse neonatal outcomes.

Outcome of Neonates Presenting With Severe Cardiac Failure due to Cerebral Arteriovenous Fistula

BACKGROUND

Congenital cerebral arteriovenous fistulas (AVFs), including vein of Galen malformations, presenting in infancy carry variable mortality and morbidity. This study aimed to describe the outcome of neonates with cerebral AVFs who present with refractory cardiac failure.

METHODS

Retrospective chart review of neonates with refractory cardiac failure due to cerebral AVFs presenting before 28 days of age in a single-center neuro-intensive care nursery over a 12-year period (2008-2020) was conducted.

RESULTS

Seventeen neonates were included. Twelve had a vein of Galen malformation, four a non-galenic pial AVF, and one a dural AVF. Seven neonates (41%) died without receiving an embolization procedure. The remaining ten were critically ill. Seven (70%) were mechanically ventilated and on nitric oxide, 5 (50%) were on pressors, and 6 (60%) had renal and/or hepatic dysfunction. Seven (70%) had pre-existing brain injury on imaging. The first embolization procedure occurred at a median age of 4 days (range: 0-8 d). Complications included intracranial hemorrhage in 8 of 10 (80%) and seizures in 5 of 8 (62%). Five (50%) neonates who underwent embolization died. Among the 5 neonates who survived, all have motor impairment. Four (80%) developed hydrocephalus requiring a ventriculoperitoneal shunt, and 2 (40%) developed epilepsy and are nonverbal.

CONCLUSION

In this cohort of critically ill neonates with cerebral AVF, all seven who did not receive embolization and half of ten who were treated died. The five survivors all have neurodevelopmental impairment. This information may be helpful to parents and providers who make decisions regarding life-sustaining treatments for neonates with cerebral AVFs and refractory cardiac failure.

Percutaneous transuterine fetal cerebral embolisation to treat vein of Galen malformations at risk of urgent neonatal decompensation: study protocol for a clinical trial of safety and feasibility

INTRODUCTION

Although endovascular techniques have improved outcomes in vein of Galen malformations (VOGM), there is still a high rate of morbidity and mortality, particularly among cases with decompensation in the neonatal period. The dimension of the draining venous sinus on fetal imaging correlates with the risk of neonatal decompensation. In fetuses within this high-risk group who do not have end-organ injury, there is a theoretical therapeutic opportunity to reduce the arteriovenous shunt before the normal physiological changes of birth precipitate decompensation. This study investigates the safety and potential benefit of treating a VOGM in utero, which has not been previously studied.

METHODS AND ANALYSIS

This study aims to enroll 20 subjects: pregnant women with a fetus harbouring a high-risk VOGM (defined on MRI by a narrowest medial-lateral width greater than 8 mm in the draining venous sinus). Unfortunately, the subset of fetuses with in utero end-organ injury is ineligible, because the late stage of pathology is not amenable to recovery from a cerebrovascular intervention, likely not even in utero. This study aims to alter the physiology before such developments accrue.At or after 23 weeks of gestation, a transuterine transposterior fontanelle needle puncture to the torcular allows ultrasound-guided deployment of coils to embolise the draining venous malformation.This study has 97.5% power to detect major safety events at 30% or greater, and 80% power to detect a reduction in the rate of neonatal intervention from 80% to 30%. In the staged study design, an interval evaluation after 11 patients invokes study termination if safety events occur above the allowed threshold.

ETHICS AND DISSEMINATION

The institutional review boards at Mass General Brigham and Boston Children's Hospital (BCH) reviewed and approved this protocol. The BCH Department of Radiology and a patient family philanthropic donation fund this study. The trial results will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

NCT04434729.

Arteriovenous Cerebral High Flow Shunts in Children: From Genotype to Phenotype

OBJECTIVE

To study the genotypes and phenotypes of cerebral arteriovenous fistulas that drain or do not drain through the vein of Galen, and true vein of Galen aneurysmal malformations, in order to determine whether genotyping could help improve classification of these malformations and their management.

METHODS

We carried out a retrospective review of genetic and phenotypic data in databases of four centers. All children with cerebral arteriovenous fistula or vein of Galen aneurysmal malformations aged below 18 years at onset were included. We recorded the nature of the genetic variant or absence of variant, age at onset, type of malformation, symptoms at onset (hemorrhage, neurological deficit, hydrocephalus, incidental, and heart failure), type of venous drainage and the long-term outcome.

RESULTS

One hundred and fifteen children were included. Autosomal dominant variants were identified in 39% of patients. The most frequent variant affected was the RASA1 gene (25%) followed by EPHB4 (8%) and the HHT-associated genes (5%). HHT gene variants were only observed in pial arteriovenous fistula not draining into the vein of Galen; on the contrary, EPHB4 variants were only seen in genuine vein of Galen aneurysmal malformation. RASA1 variants were identified in all types of shunts.

CONCLUSIONS

EPHB4 variants seem specific to the vein of Galen aneurysmal malformation, RASA1 variants are associated with either pial arteriovenous fistulas or with genuine VGAM and HHT gene variants seem specific to pial arteriovenous fistulas. The genetic data helps to classify these malformations and to guide treatment toward lowest risk of post-operative cerebral ischemic-hemorrhagic complications.

Spontaneous thrombosis of a vein of Galen malformation associated with acute sinusitis: a case report

The vein of Galen malformation is caused by an abnormal shunting between choroidal arteries and the median prosencephalic vein during embryological development, leading to increased blood flow to the deep cerebral veins, intracranial damage, and systemic repercussions. Idiopathic spontaneous thrombosis of a vein of Galen malformation is rare, and its association with acute sinusitis has not been reported in the literature. We present the case of a girl with a postnatal diagnosis of a vein of Galen malformation at the age of 16 months, with secondary pulmonary hypertension that was adequately controlled with spironolactone. At 3 years old, while expecting elective endovascular treatment, the patient developed spontaneous thrombosis of the vein of Galen malformation, concomitant to an acute sinusitis episode, with complete resolution of the vascular malformation and secondary pulmonary hypertension. The patient continued with normal neurological development over a 5-year follow-up. We discuss the main pathophysiologic mechanisms that can explain spontaneous thrombosis of VOGMs and the patient's outcome. Awareness of different mechanisms that can lead to spontaneous thrombosis can help in the decision-making process and prompt targeted approaches to individual patients with a vein of Galen malformation.

Review on the current treatment status of vein of Galen malformations and future directions in research and treatment

INTRODUCTION

Vein of Galen malformations (VOGMs) represent a rare pathologic entity with often catastrophic natural history. The advances in endovascular treatment in recent years have allowed for a paradigm shift in the treatment and outcome of these high-flow shunts, even though their pathogenetic mechanisms and evolution remain in part obscure.

AREAS COVERED

The overall management of VOGMs requires a tailored case-to-case approach, starting with in utero detection and reserving endovascular treatment for indicated cases. Lately, the advances in translational research with whole-genome sequencing and the coupling with cellular-level hemodynamics attempt to shed more light in the pathogenesis and evolution of these lesions. At the same time the advances in endovascular techniques allow for more safety and tailored technical strategy planning. Furthermore, the advances in MRI techniques allow a better understanding of their vascular anatomy. In view of these recent advances and by performing a PUBMED literature review of the last 15 years, we attempt a review of the evolutions in the imaging, management, endovascular treatment and understanding of underlying mechanisms for VOGMs.

EXPERT OPINION

The progress in the fields detailed in this review appears very promising in better understanding VOGMs and expanding the available therapeutic arsenal.

Epidemiology, Diagnostics, and Management of Vein of Galen Malformation

BACKGROUND

Vein of Galen malformation (VGM) is a rare congenital intracerebral vascular malformation. The aim of this study was to gain reliable data about epidemiology; clinical manifestations; and pre-, peri- and postinterventional treatment strategies in Germany.

METHODS

This prospective epidemiologic study was conducted by Erhebungseinheit für Seltene Pädiatrische Erkrankungen in Deutschland, a hospital-based German nationwide surveillance unit for rare pediatric diseases. Patients aged upto 18 years with a new diagnosis of VGM were prospectively included between January 1, 2014 and December 31, 2015.

RESULTS

In the two-year study period, 30 individuals with newly diagnosed VGM were identified, resulting in an estimated annual incidence rate of VGM in Germany of at least 1: 58,100 live births. The main symptoms were age dependent. Neonates presented with mainly cardiac manifestations of high output failure; infants and older children mainly suffered from neurological complications. Of the patients with endovascular treatment 95% survived, but only 41% of these patients were discharged home without any complications. The Bicêtre Neonatal Evaluation Score was a good predictor for poor outcome but could have led to palliative care in some patients with good outcome.

CONCLUSIONS

The incidence of VGM in Germany is estimated to be 1:58,100 live births. The majority of patients were eligible for endovascular treatment. Nevertheless, due to side effects and long-term sequelae in the majority of patients, further improvement in care of children with VGM is needed.

Endovascular treatment of intracranial vascular malformations in children

Paediatric intracranial vascular malformations are rare and different from adult ones in vascular anatomy, pathophysiology, and symptoms. Their impact on the brain and their symptoms will differ in the antenatal period, in neonates, infants, and children. Clinical presentation includes seizures, focal neurological deficit, haemorrhage, congestive heart failure, hydrovenous disorder, and developmental delays. These malformations are thus associated with a poor prognosis if left untreated. Therefore, aggressive management is generally recommended and must be performed by a multidisciplinary team with extensive experience. Endovascular treatment is the first-choice treatment for most paediatric intracranial vascular malformations. Indication and timing for treatment should be decided on the basis of a careful assessment of neurological symptoms, growth and development, cardiac and other systemic manifestations, and imaging of the malformation and the brain tissue. WHAT THIS PAPER ADDS: Paediatric intracranial vascular malformations are rare, but their prognosis is poor if left untreated. Improved clinical, anatomical, and pathophysiological understanding of these complex lesions has improved prognosis.

Long-term outcome of vein of Galen malformation

AIM

To describe the long-term outcomes of children by the time they reached school age with vein of Galen aneurysmal malformation (VGAM).

METHOD

This was a retrospective observational study on a consecutive cohort of patients with VGAM. We included patients with at least one Francophone parent, aged between 6 and 11 years at the time of long-term evaluation. The neurological outcome was assessed with the King's Outcome Scale for Childhood Injury score and eight neurological and behavioural items from the Rivermead Postconcussion Symptoms questionnaire.

RESULTS

All 52 patients (17 females, 32 males [data missing for n=3]) with at least one Francophone parent (5 fetuses and 47 children) were included. At the long-term evaluation time-point, 33 patients were alive and 19 patients had died. Risk of postnatal death was associated with severe neonatal cardiac failure (p=0.007) or isosystemic or suprasystemic pulmonary hypertension (p=0.014). Among survivors, 19 had a good outcome with normal schooling and 14 had a poor outcome. Moreover, among the good outcome patients, a large proportion had neurodevelopmental alterations.

INTERPRETATION

Long-term outcome of patients with VGAM appears to be less favourable than outcome described at the short- and medium-term, even in the absence of encephalomalacia at birth. Even patients with good outcome often have neuropsychological disorders that may have repercussions on learning and requiring appropriate rehabilitation or medical management.

WHAT THIS PAPER ADDS

Long-term outcome appears to be less favourable than described at short- and medium-term follow-up. Even patients with good outcome at these time-points often have minor neuropsychological disorders.

Fetal and Neonatal MRI Predictors of Aggressive Early Clinical Course in Vein of Galen Malformation

BACKGROUND AND PURPOSE

Neonates with vein of Galen malformations are split into 2 cohorts: one needing urgent neonatal embolization, with relatively high mortality and morbidity even with expert care, and a cohort in which embolization can be deferred until infancy, with far better prognosis. We aimed to identify brain MR imaging characteristics obtained from fetal and early neonatal scans that can predict the clinical presentation.

MATERIALS AND METHODS

Patients with vein of Galen malformations were stratified into a neonatal at-risk cohort if the patient needed urgent neonatal intervention or if neonatal death occurred; or an infantile treatment cohort if they were stable enough not to require treatment until >1 month of age. Twelve vascular MR imaging parameters, measured by 2 independent observers, were systematically correlated with the need for early neonatal intervention and/or neonatal mortality.

RESULTS

A total of 32 neonatal patients (21 patients in the neonatal at-risk cohort, 11 in the infantile treatment cohort) were identified. Maximal mediolateral diameter (area under the curve  = 0.866, P < .001) and cross-sectional area (area under the curve = 0.836, P = .002) at the narrowest point of the straight or falcine sinus were most predictive of clinical evolution into the neonatal at-risk cohort. There were 15 patients who had fetal MRIs (10 in the neonatal at-risk cohort and 5 in the infantile treatment cohort). Here too, maximal mediolateral diameter (area under the curve = 0.980, P = .003) and cross-sectional area (area under the curve  = 0.941, P = .007) at the narrowest point of the straight or falcine sinus were highly predictive of the neonatal at-risk cohort.

CONCLUSIONS

Early neonatal and fetal MR imaging can be readily used for accurate early risk stratification, assisting in directing resources, timing treatment decisions, and identifying appropriate cohorts for novel interventions.

Management and Outcomes of Neonatal Arteriovenous Brain Malformations with Cardiac Failure: A 17 Years' Experience in a Tertiary Referral Center

OBJECTIVES

To assess the management and outcomes of neonatal arteriovenous brain malformations (mostly vein of Galen malformations) complicated by cardiac failure in the era of prenatal diagnosis and endovascular treatment in a tertiary referral center.

STUDY DESIGN

This observational study included 77 living newborn infants with arteriovenous brain malformations with cardiac failure, admitted to our referral center from 2001 to 2017. All infants underwent cardiovascular evaluation including echocardiogram and brain magnetic resonance imaging. Long-term survivors had standard neurocognitive assessments.

RESULTS

Infants were admitted to the neonatal intensive care unit at a median of 5 days of age (including 18 inborn patients since 2009). Sixty transarterial shunt embolizations were performed in 46 patients during their first month (at a median age of 7.5 days) or postponed beyond the first month in another 10 long-term survivors. Embolization was not performed in 21 infants, including 19 nonsurvivors with severe brain injury, uncontrolled cardiac failure, or multiple organ failure. Cardiac failure requiring vasopressor infusion occurred in 48 patients (64%) during the hospitalization. Infants who survived the first month underwent a median of 3 embolization sessions. Among the 51 survivors, 21 had a good outcome and 19 had a poor outcome at follow-up (median age, 5.3 years); 11 children were lost to follow-up.

CONCLUSIONS

In the era of multidisciplinary prenatal diagnosis, using a standardized care protocol, 47% of liveborn infants with an arteriovenous shunt malformation with cardiac failure experienced a favorable outcome.

Venous pathologies in paediatric neuroradiology: from foetal to adolescent life

The interpretation of cerebral venous pathologies in paediatric practice is challenging as there are several normal anatomical variants, and the pathologies are diverse, involving the venous system through direct and indirect mechanisms. This paper aims to provide a comprehensive review of these entities, as their awareness can avoid potential diagnostic pitfalls. We also propose a practical classification system of paediatric cerebral venous pathologies, which will enable more accurate reporting of the neuroimaging findings, as relevant to the underlying pathogenesis of these conditions. The proposed classification system comprises of the following main groups: arterio-venous shunting-related disorders, primary venous malformations and veno-occlusive disorders. A multimodal imaging approach has been included in the relevant subsections, with a brief overview of the modality-specific pitfalls that can also limit interpretation of the neuroimaging. The article also summarises the current literature and international practices in terms of management options and outcomes in specific disease entities.

Outcome of vein of Galen malformation presenting in the neonatal period

OBJECTIVE

Vein of Galenaneurysmal malformation (VGAM) is a rare but important congenital malformation presenting to neonatal intensive care units (NICUs), and with a change from surgical to endovascular management, survival for this condition has improved. However, there is little reported about the medical management decisions of infants with this condition and the associated long-term neurodevelopmental outcomes. We aim to report a single centre experience of both acute treatment and long-term outcomes of VGAM for those infants admitted to our NICU soon after birth.

DESIGN

Retrospective cohort study over a 15-year period from 2001 to 2015 inclusive.

SETTING

A quaternary NICU at The Royal Children's Hospital, Melbourne, Australia.

PARTICIPANTS

24 newborn infants referred for management of VGAM. There were no eligibility criteria set for this study; all presenting infants were included.

INTERVENTIONS

None.

MAIN OUTCOMES MEASURES

Clinical neuroimaging data were gathered. Surviving children were formally assessed with a battery of tests administered by a neuropsychologist and occupational therapist/physiotherapist at various ages across early to middle childhood.

RESULTS

Fifteen neonates with VGAM did not survive beyond their NICU admission. 10 of these were not offered endovascular intervention. Of the nine surviving infants, only one had a normal neurodevelopmental outcome.

CONCLUSIONS

The mortality of VGAM presenting in the neonatal period was high, and rates of normal neurodevelopmental outcome for survivors were low. These findings contribute to our understanding of which neonates should be treated and highlights the importance of providing clinical neurodevelopmental follow-up to survivors beyond their infant years.

Quantifying the Intra-Operative Hemodynamic Effects of Glue Embolization in Vein of Galen Malformations

Vein of Galen malformation is a rare congenital pathological intracranial arteriovenous shunt which carries 30% risk of death before 28 days-of-age. Treatment is by high risk minimally invasive endovascular glue embolization of shunt feeding arteries under angiographic control. A tool to support intra-operative decision making would be useful. We present a novel method for visualizing angiography data to demonstrate the effect of the intervention based upon change the after embolization in the delay in time of peak contrast density relative to the injected artery and a novel method for quantifying the immediate effect of embolization on the hemodynamics of the shunt. The method is demonstrated on the angiograms of five neonates who underwent embolization. We show consistent results including a post-embolization increase in the delay in time of peak contrast density relative to the injected artery at the venous outflow in keeping with reduced shunting and redistribution of blood following embolization.