Implementation of 3D modelling to improve understanding and conceptualisation of arteriovenous malformation (AVM) morphology for the execution of safe microsurgical excision of complex paediatric AVMs.

INTRODUCTION: Brain arteriovenous malformations (bAVMs) present complex challenges in neurosurgery, requiring precise pre-surgical planning. In this context, 3D printing technology has emerged as a promising tool to aid in understanding bAVM morphology and enhance surgical outcomes, particularly in pediatric patients. This study aims to assess the feasibility and effectiveness of using 3D AVM models in pediatric bAVM surgery. METHODOLOGY: The study was conducted at Great Ormond Street Hospital, and cases were selected sequentially between October 2021 and February 2023. Eight pediatric bAVM cases with 3D models were compared to eight cases treated before the introduction of 3D printing models. The 3D modelling fidelity and clinical outcomes were assessed and compared between the two cohorts. RESULTS: The study demonstrated excellent fidelity between 3D models and actual operative anatomy, with a median difference of only 0.31 mm. There was no statistically significant difference in angiographic cure rates or complications between the 3D model group and the non-3D model group. Surgical time showed a non-significant increase in cases involving 3D models. Furthermore, the 3D model cohort included higher-grade bAVMs, indicating increased surgical confidence. CONCLUSION: This study demonstrates the feasibility and efficacy of utilizing 3D AVM models in pediatric bAVM surgery. The high fidelity between the models and actual operative anatomy suggests that 3D modelling can enhance pre-surgical planning and intraoperative guidance without significantly increasing surgical times or complications. Further research with larger cohorts is warranted to confirm and refine the application of 3D modelling in clinical practice.

Paediatric subarachnoid haemorrhage and severe vasospasm secondary to traumatic pseudoaneurysm of a fenestrated vertebral artery: a case report and review of the literature.

Paediatric intracranial aneurysms are rare entities accounting for less than 5% of all age intracranial aneurysms. Traumatic aneurysms are more common in children and have an association with anatomical variations such as arterial fenestrations. Here, we present a case of a child initially presenting with traumatic subarachnoid haemorrhage who returned to baseline and was discharged home only to return within 2 weeks with diffuse subarachnoid and intraventricular re-haemorrhage. A dissecting aneurysm of a duplicated (fenestrated) V4 vertebral artery segment was identified as a rare cause of rebleeding. We describe a course complicated by severe vasospasm delaying aneurysm detection and treatment. Dissecting aneurysms in children should be considered in all cases of delayed post-traumatic cranial rebleeding, particularly where there is anomalous arterial anatomy.

Multiparametric Imaging for Presurgical Planning of Craniopagus Twins: The Experience of Two Tertiary Pediatric Hospitals with Six Sets of Twins.

Conjoined twins are rare and pose a challenge to radiologists and surgeons. Craniopagus twins, where conjunction involves the cranium, are especially rare. Even in large pediatric centers, radiologists are unlikely to encounter more than one such event in their medical careers. This rarity makes it daunting to select a CT and MRI protocol for these infants. Using the experience of two tertiary pediatric hospitals with six sets of craniopagus twins, this multidisciplinary and multimodal integrated imaging approach highlights the key questions that need addressing in the decision-making process for possible surgical intervention.

Management of haemorrhagic stroke secondary to arteriovenous malformations in childhood.

AIMS: The aim of this study is to describe the outcome and management of all children who have presented with haemorrhagic stroke (HS) secondary to an arteriovenous malformation (AVM) at a single UK centre over a 13-year period. METHODS: All children with HS managed at our institution (2005-2018) were identified and those with underlying AVMs were studied. Clinical and imaging data were obtained from medical records. Outcome was scored using the Recovery and Recurrence Questionnaire. RESULTS: Ninety-three children (median age 8.8 years; 56 males; 8 neonates) presented with both global and focal features (28 had Glasgow Coma Score < 8). Haemorrhage was intraparenchymal in 72; prior risk factors present in 14. An underlying vascular lesion was identified in 68/93, most commonly AVM (n = 48). A systemic cause was found in 10, cerebral venous thrombosis in three, and 9 remain unidentified despite neuroradiological investigation. Median follow-up was 2.4 years, six died, and one was lost to follow-up. Outcome was rated as good in 60/86. Of the 48 AVMs, 3 were Spetzler-Martin (SM) grade 1, 21 SM 2, 21 SM3 and 3 SM4. One patient was treated conservatively as the AVM was too high risk to treat. At follow-up, 19 with AVM were angiographically cured, all with low SM grade and with the use of a single modality in 9 cases (all low SM grade). CONCLUSION: Although children with acute HS are extremely unwell at presentation, supportive care results in a good outcome in the majority. Complete obliteration for childhood AVMs is challenging even with low-grade lesions with multimodal treatment.

Atypical capillary malformations with subsequent diplegia: A difficult case of capillary malformation-arteriovenous malformation syndrome.

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is a rare condition associated with mutations in the genes RASA1 and EPHB4. We present a challenging case of CM-AVM in a 17-month-old boy with permanent diplegia from an undiagnosed arteriovenous malformation underlying a large atypical capillary malformation over the lower thoracic spine. This case demonstrates that clinicians should have a low threshold for neuroimaging in the context of new neurologic symptoms in patients with atypical capillary malformations.

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.

Arterial Recanalization for Access for Arterial Intervention in Children: Techniques and Outcomes.

PURPOSE: To assess technical success of arterial recanalization in children requiring repeated arterial access and intervention. MATERIALS AND METHODS: Over 14 years, 41 attempts to cross 30 arterial occlusions were made in 22 patients (13 male, 9 female). Median patient age was 12 months (15 days-14 years), and weight was 7.6 kg (3.0-77.3 kg). Techniques and outcomes were recorded. RESULTS: Twenty-five of 41 (61%) attempts at crossing an arterial occlusion were successful. Nineteen of 30 (63%) first attempts to cross occlusions were successful, and 6 of 11 (55%) repeat attempts were successful. The occluded segments were combinations of common femoral artery (n = 4), external iliac artery (n = 36), common iliac artery (n = 11), and aorta (n = 1). Complications occurred in 5 of 41(12%) attempts: 3 minor complications (hematoma, extravasation, and transient leg ischemia) and 2 major complications (rupture and thrombosis). CONCLUSIONS: Arterial access by recanalization of occluded segments is technically feasible in children, with a low complication rate.

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.

Neurosurgical management of proton beam therapy-induced moyamoya syndrome.

OBJECTIVE: Proton beam therapy (PBT) is an increasingly used treatment modality for pediatric patients with brain tumors. Moyamoya syndrome (MMS) is well recognized as a complication of traditional photon radiotherapy, however its association with PBT is less well described. The authors discuss their initial experience with the neurosurgical management of MMS secondary to PBT in a large-volume pediatric neurovascular service. METHODS: The authors performed a retrospective case review of consecutive children referred for neurosurgical management of MMS after PBT between 2009 and 2022. Patient demographic characteristics, oncological history and treatment, interval between PBT and MMS diagnosis, and MMS management were recorded. Clinical outcome at last review was classified as good if the modified Rankin Scale (mRS) score was ≤ 2 and/or the patient attended mainstream education without additional assistance. Poor outcome was defined as mRS score ≥ 3 and/or the patient received additional educational support. The recorded radiological outcomes included angiographic analysis of stenosis, evidence of brain ischemia/infarction on MRI, and postsurgical angiographic revascularization. RESULTS: Ten patients were identified. Oncological diagnosis included craniopharyngioma (n = 6), optic pathway glioma (1), ependymoma (1), Ewing sarcoma (1), and rhabdosarcoma (1). The median (interquartile range [IQR]) age at PBT was 5.1 (2.7-7.9) years. The median (IQR) age at MMS diagnosis was 7.8 (5.7-9.3) years. The median time between PBT and diagnosis of MMS was 20 (15-41) months. Six patients had poor functional status after initial oncological treatment and prior to diagnosis of MMS. All 10 patients had endocrine dysfunction, 8 had visual impairment, and 4 had behavioral issues prior to MMS diagnosis. Four patients had a perioperative ischemic event: 2 after tumor surgery, 1 after MMS surgical revascularization, and 1 after receiving a general anesthetic for an MRI scan during oncological surveillance. Seven children were treated with surgical revascularization, whereas 3 were managed medically. The incidence of ischemic events per cerebral hemisphere was reduced after surgical revascularization: only 1 patient of 7 had an ischemic event during the follow-up period after surgery. No children moved from good to poor functional status after MMS diagnosis. CONCLUSIONS: MMS can occur after PBT. Magnetic resonance angiography sequences should be included in surveillance MRI scans to screen for MMS, and families should be counseled about this complication. Management at a high-volume pediatric neurovascular center, including selective use of revascularization surgery, appears to maintain functional status in these children.

Multiple cerebral aneurysms secondary to cardiac myxoma.

A 45-year-old lady presented with transient ischemic attack symptoms. Subsequent CT and DSA revealed multiple fusiform dilatations of cerebral vessels. A search for sources of emboli led to an atrial myxoma being found on echocardiogram. She made a good recovery after resection of the atrial myxoma. The aneurysms were managed conservatively. We discuss the association of multiple cerebral aneurysms with atrial myxoma.

The treatment of a dural carotid cavernous fistula (CCF) using Onyx via a transorbital approach: a technical note.

We report the successful case of embolisation of a Barrow D (White et al. in Am J Neuroradiol 28:1415-1417, 2007) dural carotid cavernous fistula (CCF) with bilateral external carotid artery and internal carotid arterial supply, using a direct percutaneous transorbital approach with the embolic agent Onyx. In particular, we highlight the properties of Onyx which make it suitable to treat the multi-compartmental nature of CCFs. The patient developed transient complications which may be related to the volume of embolic agent used, and we discuss this point further. This is still a developing technique, and we present our case as a technical note to aid those contemplating embolisation via a transorbital approach with Onyx.

Occult posterior inferior cerebellar artery dissection requiring endovascular treatment following pediatric head trauma: case report.

This is the eighth case report of a pediatric dissecting posterior inferior cerebellar artery aneurysm. The authors present the case of a 13-year-old boy who presented with posttraumatic posterior fossa subdural, subarachnoid, and intraventricular hemorrhage with hydrocephalus. Initial vascular imaging findings were negative; however, a high level of suspicion is necessary. The aneurysm was identified on day 20, after recurrence of hydrocephalus, and was treated with endovascular vessel sacrifice. The patient made a good recovery. It is important to consider arterial dissection in pediatric traumatic brain injury, especially with suspicious findings on initial CT scan and clinical presentation out of proportion to the mechanism of injury. Delayed vascular imaging is imperative for appropriate management.

Arterio-venous malformations of the ear: Description of distinct anatomical presentation and multidisciplinary management approach.

BACKGROUND: Arterio-venous malformations (AVMs) of the ear are a rare entity and their management should be decided in a dedicated multidisciplinary team (MDT) setting. The aim of this study is to describe the distinct anatomical patterns of the auricular AVMs in our unit and propose a combined interventional radiological and surgical approach. MATERIALS AND METHODS: All consecutive patients presenting with AVMs of the ear and reviewed by the Vascular Anomalies MDT between 2014 and 2019 were included in this study. Signs, symptoms, diagnostic investigations and operative findings were collected prospectively. RESULTS: After reviewing our nine patients, we identified four anatomical patterns of auricular AVMs: I: involves just a component of the ear and should undergo embolization followed by excision and reconstruction without significant loss of form; II: affects the superior two-thirds of the ear, sparing the lobule and part of the conchal bowl; these patients should undergo embolization, excision and monitoring before formal reconstruction of the ear is offered; III: involves the entire ear and should undergo embolization and pinnectomy; if there is no recurrence, the patients can be offered either a carved-rib cartilage reconstruction or a prosthesis, depending on the quality of the surrounding soft-tissues; IV: involves the ear and surrounding tissue, making surgical management and subsequent reconstruction extensive. CONCLUSION: The management of auricular AVMs is based on the extent of the ear involved. We feel that our combined interventional radiological and surgical approach will aid the management of these complex patients.

Aspirin Preventing Occlusion after Coil Migration into the Distal Anterior Cerebral Artery.

Endovascular coil embolization of cerebral aneurysm is a common procedure for managing cerebral aneurysms. We present a rare case of immediate silent coil migration into the pericallosal artery, without distal occlusion, following successful embolization. Despite the entire coil sitting within the lumen of the artery, good distal flow was observed. The patient remained asymptomatic throughout and had a good long-term (three years to date) outcome (modified Rankin Scale score of 1). We believe that the novel protective factor was the routine use of a single anti-platelet post-procedure.

Fatal hemorrhage after attempted treatment of a basilar artery stenosis. Case report.

Interventional treatment of severe intracranial stenoses using angioplasty and stent placement carries a significant risk of severe adverse events. These events are frequently caused by the intraarterial dilation but may also be precipitated by other causes related to the procedure. The authors describe a fatal subarachnoid hemorrhage during the treatment of a basilar artery (BA) stenosis caused by a vascular rupture distant from the site of angioplasty. After successful balloon dilation, an attempt to deploy a self-expanding stent failed due to the severe kinking of the stenotic segment of the BA. The angiogram performed during the intervention revealed a fatal rupture of the BA in a location not related to the angioplasty or guide wire tip. The technical aspects of the intervention are analyzed on the basis of the postmortem findings.

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.

Abciximab for thrombolysis during intracranial aneurysm coiling.

INTRODUCTION: Thrombotic events are a common and severe complication of endovascular aneurysm treatment with significant impact on patients' outcome. This study evaluates risk factors for thrombus formation and assesses the efficacy and safety of abciximab for clot dissolution. MATERIALS AND METHODS: All patients treated with abciximab during (41 patients) or shortly after (22 patients) intracranial aneurysm coil embolisation were retrieved from the institutional database (2000 to 2007, 1,250 patients). Sixty-three patients (mean age, 55.3 years, +/- 12.8) had received either intra-arterial or intravenous abciximab. Risk factors for clot formation were assessed and the angiographic and clinical outcome evaluated. RESULTS: No aneurysm rupture occurred during or after abciximab application. The intra-procedural rate of total recanalisation was 68.3%. Thromboembolic complications were frequently found in aneurysms of the Acom complex and of the basilar artery, whilst internal carotid artery aneurysms were underrepresented. Two patients died of treatment-related intracranial haemorrhages into preexisting cerebral infarcts. Two patients developed a symptomatic groin haematoma. CONCLUSIONS: Abciximab is efficacious and safe for thrombolysis during and after endovascular intracranial aneurysm treatment in the absence of preexisting ischaemic stroke.

Reduction of severe visual loss and complications following intra-arterial chemotherapy (IAC) for refractory retinoblastoma.

BACKGROUND: Intra-arterial chemotherapy (IAC) for retinoblastoma has been documented as causing visual loss and ocular motility problems. A lack of safety data has precluded its acceptance in all centres. METHODS: Retrospective cohort study of patients with retinoblastoma from 2013 to 2015 who had a healthy foveola and relapsed following systemic chemotherapy. All required IAC. The correlation of complications with doses of melphalan +/- topotecan used and putative catheterisation complications was assessed. Ocular complications were determined using vision, macular (including pattern visual evoked potentials (PVEPs)), retinal electroretinograms (ERGs) and ocular motility functions. Efficacy (tumour control) was also assessed. RESULTS: All eyes had age appropriate doses of melphalan with five having additional doses of topotecan. Severe physiological reactions requiring adrenaline were seen in six patients during the catheterisation procedure. Difficulty was documented in accessing the ophthalmic artery in 7/27 catheterisations. The median/mean number of courses of chemotherapy was three. No child had severe visual loss as assessed by age appropriate tests (median follow-up 20.9 months, range 3.7-35.2 months). One child had nasal choroidal ischaemia and a sixth nerve palsy. Post-IAC PVEPs were performed in eight and reported as normal. All post-IAC ERGs were normal apart from one (total dose 20 mg melphalan 0.8 mg topotecan). Tumour control was achieved in six of nine cases. CONCLUSION: The proportion of visual and ocular motility complications may be reduced by providing age-adjusted doses of melphalan. Dose rather than complications from catheterisation is the most important risk factor for ocular injury.