That which is unseen: 3D printing for pediatric cerebrovascular education.

INTRODUCTION: Pediatric cerebrovascular lesions are very rare and include aneurysms, arteriovenous malformations (AVM), and vein of Galen malformations (VOGM). OBJECTIVE: To describe and disseminate a validated, reproducible set of 3D models for optimization of neurosurgical training with respect to pediatric cerebrovascular diseases METHODS: All pediatric cerebrovascular lesions treated at our institution with adequate imaging studies during the study period 2015-2020 were reviewed by the study team. Three major diagnostic groups were identified: aneurysm, AVM, and VOGM. For each group, a case deemed highly illustrative of the core diagnostic and therapeutic principles was selected by the lead and senior investigators for printing (CSG/JM). Files for model reproduction and free distribution were prepared for inclusion as Supplemental Materials. RESULTS: Representative cases included a 7-month-old female with a giant left MCA aneurysm; a 3-day-old male with a large, complex, high-flow, choroidal-type VOGM, supplied from bilateral thalamic, choroidal, and pericallosal perforators, with drainage into a large prosencephalic vein; and a 7-year-old male with a left frontal AVM with one feeding arterial vessel from the anterior cerebral artery and one single draining vein into the superior sagittal sinus CONCLUSION: Pediatric cerebrovascular lesions are representative of rare but important neurosurgical diseases that require creative approaches for training optimization. As these lesions are quite rare, 3D-printed models and open source educational materials may provide a meaningful avenue for impactful clinical teaching with respect to a wide swath of uncommon or unusual neurosurgical diseases.

Spontaneous thrombosis of vein of Galen malformation managed with surgical resection: a case­based review.

INTRODUCTION: Vein of Galen malformation (VOGM) is an exceptionally uncommon form of congenital intracranial vascular malformations. It is highly unusual for this lesion to spontaneously thrombose. The clinical presentation of a patient may range from being asymptomatic to critically ill. The underlying pathophysiological mechanisms that cause spontaneous thrombosis are still poorly understood. METHODS AND RESULTS: The literature on spontaneous thrombosis of VOGM was systematically reviewed, analyzed, and summarized with a focus on its pathophysiology, types, clinical presentations, diagnosis, management, and outcomes. It was also illustrated with a case presentation. The case presents an unusual presentation and location of a VOGM in a 2-year-old boy who was successfully treated with surgical resection. CONCLUSIONS: A handful of cases of thrombosed VOGM have been reported worldwide where surgery was used to treat the condition. Low-flow fistulas of the mural type are prone to spontaneous thrombosis, have delayed clinical presentations, and are typically diagnosed in young children. Among the many possible manifestations, hydrocephalus is by far the most common. In the absence of blood flow, MRI is the diagnostic test of choice. Depending on the patient's symptoms, surgery to either remove the aneurysm or divert the cerebrospinal fluid usually results in a good prognosis.

A cardiopulmonary bypass strategy to support a patient with vein of Galen malformation.

We present a dissection of the patent ductus arteriosus and pulmonary artery for surgical repair utilising cardiopulmonary bypass in the setting of vein of Galen malformation. Several strategies were employed to attenuate the cerebral shunt including pH-stat, high cardiac index, restrictive venous drainage, continuous ventilation and deep hypothermic circulatory arrest. The patient recovered from surgery with no apparent neurological sequelae.

Management of Jugular Bulb Stenosis in Pediatric Vein of Galen Malformation: A Novel Management Paradigm.

INTRODUCTION: Pediatric vein of Galen malformations (VOGMs) are fistulous intracranial malformations arising congenitally within the choroidal fissure that can present with an array of neurological and cardiac sequelae. Associated venous stenosis may result in intracranial venous hypertension and ischemia leading to severe, irreversible cerebral injury. Management of neonatal VOGMs typically involves staged embolization and angioplasty/stenting for relief of venous stenosis. Rarely, jugular foraminal narrowing has been identified as causing jugular bulb stenosis. CASE PRESENTATION: We present the case of a 22-month-old female diagnosed with VOGM prenatally who displayed persistent intracranial venous hypertension despite multiple neuroembolization procedures during the neonatal period. Following initial reduction in arteriovenous shunting, she once again developed venous hypertension secondary to jugular bulb stenosis for which angioplasty was attempted. Failure of angioplasty to relieve the venous hypertension prompted skull base imaging, which revealed jugular foraminal ossification and stenosis. Microsurgical jugular foraminotomy followed by balloon angioplasty and stenting significantly reduced jugular pressure gradients. Restenosis requiring re-stenting developed postoperatively at 9 months, but the patient has remained stable with significant improvement in cortical venous congestion. DISCUSSION/CONCLUSION: This case demonstrates the efficacy of microsurgical decompression of the jugular foramen and endovascular angioplasty/stenting as a novel treatment paradigm for the management of intracranial venous hypertension in the setting of VOGM.

Hirayama Disease in a Patient with a History of Late-Onset Symptomatic Vein of Galen Aneurysmal Malformation.

INTRODUCTION: The purpose of this report is to present a rare case of Hirayama disease (HD) in a patient with a history of late-onset symptomatic vein of Galen aneurysmal malformation (VGAM). This report may provide new insights into the pathophysiology of HD, a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. These symptoms are believed to result from cervical myelopathy affecting the anterior horn cells due to abnormal compressive forces on the spinal cord from adjacent anatomical structures (i.e., dura and/or epidural veins), but this has not been proven. VGAM is a rare congenital cerebral vascular malformation, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders, which most frequently presents in the early neonatal period with congestive heart failure. CASE PRESENTATION: We report the case of an otherwise healthy boy who presented with heart failure due to VGAM at 7 years and subsequently presented at 14 years with left-sided HD. His cervical MRI with neck flexion revealed enlarged epidural veins at the C5-C6 spinal level with anterior, leftward displacement of the posterior dura and spinal cord as well as left hemicord flattening and/or atrophy at this level. He underwent successful surgical treatment by C5-C6-C7 osteoplastic laminotomies and tenting and expansile autologous duraplasty, during which enlarged, engorged epidural veins were confirmed and coagulated. This halted the progression of his left hand weakness and atrophy and allowed significant functional improvement. Postoperative catheter angiogram showed no anatomical connection between the persistent VGAM and the engorged epidural veins, and genetic testing revealed no genetic predisposition of vascular malformations. DISCUSSION/CONCLUSION: In this patient, a combined surgical technique was performed that included epidural venous plexus coagulation with posterior autologous duraplasty and dural fixation using tenting sutures. This combined approach led to a favorable clinical and radiographic outcome with no complications or limitations and has not been previously proposed in the literature, to our knowledge. Although not completely ruled out, we found no angiographic connection or genetic predisposition to suggest there is a pathophysiological link between HD and VGAM.

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

OBJECTIVE: Describe the course and outcomes in a UK national cohort of neonates with vein of Galen malformation identified before 28 days of life. METHODS: Neonates with angiographically confirmed vein of Galen malformation presenting to 1 of 2 UK treatment centers (2006-2016) were included; those surviving were invited to participate in neurocognitive assessment. Results in each domain were dichotomized into "good" and "poor" categories. Cross-sectional and angiographic brain imaging studies were systematically interrogated. Logistic regression was used to explore potential outcome predictors. RESULTS: Of 85 children with neonatal vein of Galen malformation, 51 had survived. Thirty-four participated in neurocognitive assessment. Outcomes were approximately evenly split between "good" and "poor" categories across all domains, namely, neurological status, general cognition, neuromotor skills, adaptive behavior, and emotional and behavioral development. Important predictors of poor cognitive outcome were initial Bicêtre score ≤ 12 and presence of brain injury, specifically white matter injury, on initial imaging; in multivariate analysis, only Bicêtre score ≤ 12 remained significant. INTERPRETATION: Despite modern supportive and endovascular treatment, more than one-third of unselected newborns with vein of Galen malformation did not survive. Outcome was good in around half of survivors. The importance of white matter injury suggests that abnormalities of venous as well as arterial circulation are important in the pathophysiology of brain injury. Ann Neurol 2018;84:547-555.

Presentation, course, and outcome of postneonatal presentations of vein of Galen malformation: a large, single-institution case series.

AIM: To describe presentation, clinical course, and outcome in postneonatal presentations of vein of Galen malformation (VGM). METHOD: Children older than 28 days presenting with VGM (from 2006-2016) were included. Notes/scans were reviewed. Outcome was dichotomized into 'good' or 'poor' using the Recovery and Recurrence Questionnaire. Logistic regression was performed to explore relationships between clinico-radiological features and outcome. RESULTS: Thirty-one children (18 males, 13 females) were included, presenting at a median age of 9.6 months (range 1.2mo-11y 7mo), most commonly with macrocrania (n=24) and prominent facial veins (n=9). Seven had evidence of cardiac failure. VGM morphology was choroidal in 19. Hydrocephalus (n=24) and loss of white matter volume (n=15) were the most common imaging abnormalities. Twenty-nine patients underwent glue embolization (median two per child). Angiographic shunt closure was achieved in 21 out of 28 survivors. Three children died of intracranial haemorrhage (1y, 6y, and 30d after embolization). Ten patients underwent neurosurgical procedures; to treat haemorrhage in four, and hydrocephalus in the rest. Outcome was categorized as good in 20 out of 28 survivors, but this was not predictable on the basis of the variables listed above. INTERPRETATION: Postneonatally presenting VGM has distinctive clinico-radiological features, attributable to venous hypertension. Endovascular treatment is associated with good outcomes, but more specific prognostic prediction was not possible within this cohort. WHAT THIS PAPER ADDS: Clinical and radiological features in older children with vein of Galen malformation relate to venous hypertension. Outcome is good in most cases with endovascular therapy. Mortality is low but is related to intracranial haemorrhage.

Galenic pial arteriovenous fistulas: Angioarchitecture, clinical presentation, and therapeutic considerations.

Vein of Galen (VG) aneurysmal malformations (VGAMs) are complex vascular lesions. Their etiopathogenesis is extensively debated and remains poorly understood. Strictly speaking, true VGAMs are Galenic pial arteriovenous fistulas. They are believed to arise in utero and are contended to drain either into the true VG or the median prosencephalic vein of Markowski. Several classification systems have been proposed and are widely used. With the advent of endovascular therapy, precise understanding of the angioarchitecture is critical for management and therapeutic decision making. We review clinical presentation and diagnostic imaging findings, discussing angioarchitectural properties as they relate to treatment planning. Clin. Anat. 31:259-268, 2018. © 2017 Wiley Periodicals, Inc.

Hydrocephalus in vein of Galen malformation: etiologies and therapeutic management implications.

BACKGROUND: Up to now, only little is known about hydrocephalus (HC) in vein of Galen malformation (VGM). We want to present the different etiologies and our long-term experience (1992-2015) in the management of HC. METHODS: Out of 44 treated children with VGM, we retrospectively reviewed all cases with HC. We analyzed the etiologies, our treatment results and complications. RESULTS: Twenty-one children (48 %) presented either with HC or developed it over time. In 21 % of those cases, high venous pressure was presumably the sole cause. Until 2009, seven of them received ventriculoperitoneal (VP) shunting; six of those resulted in severe postoperative complications. The remaining children have been treated successfully by endovascular embolization. Five out of the 44 children (11 %) developed HC after intraventricular hemorrhage. In four cases, those children were treated with positive results by using transient external ventricular drainages. In one case a VP shunt with highest valve pressure was inserted. Another four children (9 %) presented with aqueductal stenosis-related HC caused by either dilated venous outflow or space-occupying coil masses after embolization. The latter case was successfully treated by ventriculocisternostomy, whereas endovascular treatment decreased the venous outflow in size and thus resolved the HC in the other cases. In the remaining cases (7 %), atrophy due to melting brain syndrome led to HC ex vacuo. CONCLUSIONS: HC in VGM is a common phenomenon with several etiologies requiring different treatments. In most cases, embolization of the VGM as sole treatment is completely sufficient in order to decrease high venous pressure. However, certain other causes of HC should be treated in an interdisciplinary setting by specialized neurosurgeons.

Flow control using Scepter™ balloons for Onyx embolization of a vein of Galen aneurysmal malformation.

PURPOSE: We present a technical development of the endovascular treatment technique for vein of Galen aneurysmal malformation, using Onyx™ (ethylene vinyl alcohol copolymer) delivered under flow control through double-lumen balloon microcatheters. MATERIALS AND METHODS: An 11-month-old patient that initially presented with increasing head circumference was diagnosed with mural type vein of Galen aneurysmal malformation. Complete cure was obtained in a single endovascular treatment session. Onyx was delivered simultaneously through two double-lumen balloon microcatheters (Scepter™, Microvention, Terumo Group). In both arterial feeders, balloon inflation occluded the high-flow arterial-venous shunting and thus facilitated the controlled propagation of the embolic product in the afferent artery and the shunt point while preventing distal migration into the venous system. RESULTS: Two years post-procedure, MR imaging showed persistent occlusion of arterial-venous shunts with complete regression of the venous dilatation. On clinical examination, the patient had no neurological deficits, and no cognitive impairment was detected at neuropsychological testing. CONCLUSION: The use of double-lumen balloon microcatheters for flow control during delivery of Onyx represents a viable alternative for the endovascular treatment of vein of Galen aneurysmal malformations.

Vein of Galen Malformations.

Significant efforts have been made over the last few decades to improve the diagnosis and management of patients with vein of Galen malformations (VOGMs). The mainstays of treatment remain focused on primary endovascular management by staged transarterial embolizations with adjunctive use of transvenous embolization, medical therapy, and neurosurgical intervention for symptom control in select patients. Innovation in endovascular technology and techniques as well as promising new genomic research elucidating potential therapeutic targets hold significant promise for the future of VOGM treatment.

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.

[A case of vein of Galen aneurysmal malformation with a newly developed dural arteriovenous fistula after successful embolization].

We report a case of vein of Galen aneurysmal malformation (VGAM) with a newly developed dural arteriovenous fistula (AVF) subsequent to successful embolization. A male neonate diagnosed as VGAM with prenatal ultrasonography and MRI presented severe cardiac and respiratory failure soon after birth. Five sessions of transarterial embolization using NBCA were performed during the first 6 months of his life. The shunt flow was effectively reduced and heart failure was resolved after the treatment. Follow-up angiography performed 2.5 years after the last embolization revealed complete obliteration of VGAM and newly developed small dural AVF on the wall of the thrombosed falcorial sinus. We believe that the dural AVF in this case was caused by local venous hypertension or induction of angiogenic factor during the thrombosing process of VGAM.

[Arteriovenous malformations of the Galen vein: results of treatment].

UNLABELLED: We performed retrospective and prospective analysis of surgical treatment of arteriovenous malformations of vein of Galen. Since 1987 till 2009 90 patients were operated in Burdenko Neurosurgical Institute. Age varied between 1 month and 38 years, 69 patients were children below 10. The paper describes main techniques for early diagnosis of the disease, its manifestation depending on age and type of malformation, treatment modalities, early postoperative and follow-up results. Endovascular treatment was applied in 75 (83.3%) patients. Complications with persistent neurological deficit after endovascular occlusion were observed in 10 (16%) patients, 2 patients died shortly after surgery. CONCLUSION: endovascular surgery is the treatment of choice in arteriovenous malformations of vein of Galen; optimal age for endovascular procedure is 4-5 months; observation in asymptomatic course is ineffective.

Vascular Lesions of the Pineal Region: A Comprehensive Review of the Therapeutic Options.

OBJECTIVE: Vascular lesions of the pineal region comprise aneurysms of the pineal region, arteriovenous malformations, cavernous malformations, and vein of Galen malformations. In the present report, we have offered an extensive review of each vascular pineal region lesion. METHODS: We performed an extensive literature review, focusing on the current therapeutic options available for the different vascular lesions of the pineal region. RESULTS: Vascular lesions of the pineal region are rare. Microneurosurgery remains a valid treatment of cavernomas, arteriovenous malformations, and aneurysms. Endovascular treatments seem to be the first option for the vein of Galen malformations, followed by microneurosurgery. Radiosurgery seems beneficial for small-size arteriovenous malformations. Complex and large vascular lesions will require a combination of multiple treatments. CONCLUSIONS: Vascular lesions of the pineal region are complex, uncommon diseases. Thus, definitive therapeutic modalities for these lesions require further research.

Endoscopic third ventriculostomy in an infant with vein of Galen aneurysmal malformation treated by endovascular occlusion: Case report and a review of literature.

INTRODUCTION: Vein of Galen aneurysmal malformations (VGAMs) can, through multiple mechanisms, complicate with hydrocephalus (HCP). It is generally agreed that management strategies in this scenario should focus on endovascular embolizations. Treatment options for non-responders, however, have been only scarcely reported upon. CASE PRESENTATION: We present a nine-month-old boy with a mural type VGAM complicated by HCP. Despite endovascular occlusion of the sole feeder, the child exhibited hydrocephalus progression prompting an Endoscopic Third Ventriculostomy (ETV). This procedure restored a cerebrospinal fluid (CSF) circulation otherwise impaired by aqueduct obstruction. Later, a new feeder arose and a second embolization was ultimately needed in order to achieve VGAM regression. Throughout four years of follow up, the child attained all developmental marks. DISCUSSION/CONCLUSION: VGAMs are prone to hydrocephalus development as there is both an underlying venous congestion and a mechanical, obstructive component. Although there is a rationale for addressing both components, the underlying AV shunts and subsequent venous pressure elevations usually determine failure of traditional CSF shunting strategies. It is therefore challenging to manage HCP in patients who failed to improve following endovascular embolizations. For such cases, ETV stands as an elegant minimal invasive alternative with potential to provide a more physiologic drainage route and thus better allow for neurological development.

Endovascular management of vein of Galen aneurysmal malformations. Influence of the normal venous drainage on the choice of a treatment strategy.

INTRODUCTION: Vein of Galen arteriovenous malformations (VGAM) are rare intracranial vascular lesions mostly involving young children. Endovascular therapy is the current standard of care. Albeit interventional techniques have greatly reduced the once dismal vital and functional prognoses previously associated with these lesions, the treatment of VGAMs remains a complex therapeutic challenge. DISCUSSIONS: This article reviews the available endovascular options for VGAM therapy, emphasizing three points that we have identified as critical in our practice for the establishment of a treatment strategy: (1) the importance of the deep cerebral venous anatomy, in particular the existence of normal drainage through the Galenic system in spite of the VGAM; (2) the concept of treatment staging, for arterial as well as for venous interventions; and (3) the definition of a therapeutic goal that can be attained at a reasonable cost in terms of complication risks and functional outcome.