Recognition of the variant type of spinal dural arteriovenous fistula: a rare but important consideration.

Objective: Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series.

Current Concepts in Intracranial Interstitial Fluid Transport and the Glymphatic System: Part II-Imaging Techniques and Clinical Applications.

The glymphatic system is a recently discovered network unique to the central nervous system that allows for dynamic exchange of interstitial fluid (ISF) and cerebrospinal fluid (CSF). As detailed in part I, ISF and CSF transport along paravascular channels of the penetrating arteries and possibly veins allow essential clearance of neurotoxic solutes from the interstitium to the CSF efflux pathways. Imaging tests to investigate this neurophysiologic function, although challenging, are being developed and are reviewed herein.

Current Concepts in Intracranial Interstitial Fluid Transport and the Glymphatic System: Part I-Anatomy and Physiology.

Normal physiologic function of organs requires a circulation of interstitial fluid to deliver nutrients and clear cellular waste products. Lymphatic vessels serve as collectors of this fluid in most organs; however, these vessels are absent in the central nervous system. How the central nervous system maintains tight control of extracellular conditions has been a fundamental question in neuroscience until recent discovery of the glial-lymphatic, or glymphatic, system was made this past decade.

Improving long-term outcomes in pediatric torcular dural sinus malformations with embolization and anticoagulation: a retrospective review of The Hospital for Sick Children experience.

Objective: Torcular dural sinus malformations (tDSMs) are rare pediatric cerebrovascular malformations characterized by giant venous lakes localized to the midline confluence of sinuses. Historical clinical outcomes of patients with these lesions were poor, though better prognoses have been reported in the more recent literature. Long-term outcomes in children with tDSMs are uncertain and require further characterization.

Clinical and Angioarchitectural Features of Hemorrhagic Brain Arterio-Venous Malformations in Adults and Children: Contrasts and Implications on Outcome.

Background: Hemorrhage from brain arteriovenous malformations (bAVMs) is estimated at 3% per annum. Features influencing risk of hemorrhage include perforator/posterior circulation supply, associated aneurysms, and deep drainage. Children are more likely to present with bAVM bleeds.

Embolization strategies for intracranial dural arteriovenous fistulas with an isolated sinus: a single-center experience in 20 patients.

Background: Intracranial dural arteriovenous fistulas (DAVFs) draining into an isolated sinus segment constitute a specific entity within the spectrum of cranial dural AV shunts, with under-reporting of their optimal treatment.

Objective: To describe the multimodal treatment approach to isolated sinus DAVFs in a large single-center cohort.

Methods: Retrospective analysis of adult patients with an isolated sinus DAVF treated at our institution between 2004 and 2020 was performed.

Deep venous communication in vein of Galen malformations: incidence, Imaging, and Implications for treatment.

Background: Failure to appreciate deep venous drainage pathways is a major cause of severe complications in the endovascular treatment of vein of Galen aneurysmal malformations (VOGMs).

Objective: To report deep venous drainage patterns in patients with VOGM, emphasizing the internal cerebral veins, and to describe the challenges in evaluating these.

Methods: Patients with VOGM presenting to our institute between 2000 and 2018 were retrospectively analyzed.

Factors Contributing to Major Neurological Complications From Vein of Galen Malformation Embolization.

Importance: Major neurological complications from the embolization of vein of Galen malformations (VOGMs) are poorly understood. We provide a detailed analysis of contributors to periprocedural neurological complications and lessons learned.

Objective: To assess the rate of major periprocedural neurological complications following VOGM embolization with major procedural and strategic contributors.

Surgical Treatment vs Nonsurgical Treatment for Brain Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia: A Retrospective Multicenter Consortium Study.

Background: Cerebral arteriovenous malformations (AVMs) are common in patients with hereditary hemorrhagic telangiectasia (HHT). However, due to the rarity of HHT and little published evidence of outcomes from management of brain AVMs in this disease, current international HHT guidelines recommend an individualized approach. Specifically, the outcomes for surgical vs nonsurgical management of these lesions have not been reported to date.

Trigeminal neuralgia caused by a new variant of persistent trigeminal artery associated with agenesis of internal carotid artery.

We report a hitherto undescribed persistent carotid vertebral anastomosis associated with ipsilateral internal carotid artery agenesis and bilateral duplication of the intradural vertebral arteries. This rare anomaly was detected on MRI, supplemented by CT angiography while evaluating for cause trigeminal neuralgia in a 37-year-old woman. The aberrant vessel was seen to cause thinning and lateral displacement of the left trigeminal nerve on CISS 3D images.

ELAPSS score for prediction of risk of growth of unruptured intracranial aneurysms.

Objective: To develop a risk score that estimates 3-year and 5-year absolute risks for aneurysm growth.

Methods: From 10 cohorts of patients with unruptured intracranial aneurysms and follow-up imaging, we pooled individual data on sex, population, age, hypertension, history of subarachnoid hemorrhage, and aneurysm location, size, aspect ratio, and shape but not on smoking during follow-up and family history of intracranial aneurysms in 1,507 patients with 1,909 unruptured intracranial aneurysms and used aneurysm growth as outcome. With aneurysm-based multivariable Cox regression analysis, we determined predictors for aneurysm growth, which were presented as a risk score to calculate 3-year and 5-year risks for aneurysm growth by risk factor status.

Management of a large diffuse maxillofacial arteriovenous malformation previously treated with ligation of ipsilateral arterial supply.

A 32 year-old male presented with a pulsatile facial mass with palpable thrill and audible bruit. Imaging revealed a very large diffuse left-sided facial arteriovenous malformation with extensive bilateral supply, as well as a previously ligated left external carotid artery. Endovascular treatment was required to control associated hemorrhagic events as well as for palliation and was delivered via the contralateral and ipsilateral collateral supply because of ligation of the direct route to the nidus.

Novel Technique Using Cyanoacrylate and Local Hemostatic Agents in the Management of High-Risk Exodontia Bleeding in a Patient With a Large Facial Arteriovenous Malformation.

Purpose: This report describes a case of a 32-year-old woman who had been diagnosed with a facial arteriovenous malformation during childhood. Because this patient possessed a major risk of perioperative hemorrhage, the use of several local hemostatic measures was thoroughly explored before routine exodontia.

Materials And Methods: Selective embolization of the right superior thyroid artery was performed intraoperatively and a novel hemostatic technique using a combination of a packing of Gelfoam wrapped in Surgicel was placed within the extraction sites and sealed with SwiftSet.

Venous vascular malformation of the floor of mouth masquerading as a dermoid tumor.

Venous vascular malformations (VVMs) are described as abnormal post-capillary lesions which exhibit low flow. These are typically malleable and may grow with endocrine fluctuations. A VVM that mimics the classic appearance of dermoid tumor on imaging has never been reported.

Clinical course of untreated cerebral cavernous malformations: a meta-analysis of individual patient data.

Background: Cerebral cavernous malformations (CCMs) can cause symptomatic intracranial haemorrhage (ICH), but the estimated risks are imprecise and predictors remain uncertain. We aimed to obtain precise estimates and predictors of the risk of ICH during untreated follow-up in an individual patient data meta-analysis.

Methods: We invited investigators of published cohorts of people aged at least 16 years, identified by a systematic review of Ovid MEDLINE and Embase from inception to April 30, 2015, to provide individual patient data on clinical course from CCM diagnosis until first CCM treatment or last available follow-up.

Imaging diagnosis and the role of endovascular embolization treatment for vascular intraspinal tumors.

Intraspinal tumors comprise a large spectrum of neoplasms, including hemangioblastomas, paragangliomas, and meningiomas. These tumors have several common characteristic imaging features, such as highly vascular mass appearance in angiography, hypointense rim and serpentine flow voids in MRI, and intense enhancement after intravenous contrast administration. Due to their rich vascularity, these tumors represent a special challenge for surgical treatment.

Hemorrhage rates from brain arteriovenous malformation in patients with hereditary hemorrhagic telangiectasia.

Background And Purpose: Hereditary hemorrhagic telangiectasia (HHT) is a systemic disease characterized by mucocutaneous telangiectasias, epistaxis, and arteriovenous malformations (AVMs). Intracranial hemorrhage (ICH) rates in this population are not well described. We report ICH rates and characteristics in HHT patients with brain AVMs (HHT-BAVMs).

PHASES Score for Prediction of Intracranial Aneurysm Growth.

Background And Purpose: Growth of an intracranial aneurysm occurs in around 10% of patients at 2-year follow-up imaging and may be associated with aneurysm rupture. We investigated whether PHASES, a score providing absolute risks of aneurysm rupture based on 6 easily retrievable risk factors, also predicts aneurysm growth.

Methods: In a multicenter cohort of patients with unruptured intracranial aneurysms and follow-up imaging with computed tomography angiography or magnetic resonance angiography, we performed univariable and multivariable Cox regression analyses for the predictors of the PHASES score at baseline, with aneurysm growth as outcome.

Natural history and management of basilar trunk artery aneurysms.

Background And Purpose: Basilar trunk aneurysms (BTAs), defined as aneurysms distal to the basilar origin and proximal to the origin of the superior cerebellar artery, are rare and challenging to manage. We describe the natural history and management in a consecutive series of BTAs.

Methods: Between 2000 and 2013, 2522 patients with 3238 aneurysms were referred to our institution for aneurysm management.