Epidemiology, clinical presentation, diagnostic evaluation, and prognosis of cerebral dural arteriovenous fistulas

Dural Arteriovenous Fistula

Dural arteriovenous fistulas are rare cerebrovascular lesions arising from abnormal connections between an artery and a vein. Though rare, high-grade aggressive lesions can cause hemorrhagic events and non-hemorrhagic neurologic deficits if left untreated. Treatment options vary based on angioarchitecture, location, and patient characteristics and range from conservative observation to palliative treatment, radiosurgery, endovascular embolization, and open surgery. The main goal of treatment is to obliterate flow through the abnormal connection and prevent further arterial flow to the venous system.

Tigroid Enhancement: A Characteristic Enhancement Pattern of the Cerebellar Hemisphere on MRI With Intracranial Dural Arteriovenous Fistulas

PURPOSE

This study aims to investigate a characteristic cerebellar hemisphere enhancement pattern on magnetic resonance imaging (MRI) that could aid in early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs).

MATERIALS AND METHODS

Pretreatment MR images of 57 patients with intracranial DAVFs between January 1, 2017, and February 28, 2023, were retrospectively analyzed. A total of 128 patients with confirmed alternative cerebellar lesions during the same period were included as a control group. All patients underwent enhanced MRI with a 3.0T scanner. The presence or absence of parallel enhanced linear striations on the surface of the cerebellar lesions was documented. Statistically significant differences were determined by the Fisher exact test.

RESULTS

Cerebellar lesions were identified in 4 intracranial DAVF patients (7.0%). All 4 patients were male, with an average age of 64 years (range: 58-76 years). The pretreatment MR images of all 4 DAVF patients with cerebellar lesions demonstrated the characteristic tigroid enhancement pattern. Tortuous flow voids were present in the MR images of 3 of the 4 patients. Tigroid enhancement pattern was not observed in the remaining 53 intracranial DAVF patients and all control patients. The differences in the incidence of the pattern were significant (p=0.01).

CONCLUSION

A characteristic tigroid enhancement pattern of the cerebellar hemisphere on MRI may aid in the early and specific diagnosis of intracranial DAVFs, allowing timely treatment and improving outcomes.

CLINICAL IMPACT

The identification of a characteristic tigroid enhancement pattern on MRI for cerebellar hemisphere lesions holds significant promise for clinical practice. This pattern serves as a distinctive marker aiding in the early and specific diagnosis of intracranial dural arteriovenous fistulas (DAVFs). Clinicians can now utilize this innovative finding to expedite diagnostic workflows, enabling timely intervention and management strategies. The incorporation of this novel imaging feature enhances diagnostic accuracy, potentially reducing misdiagnosis rates and preventing delays in treatment initiation. Ultimately, this advancement may lead to improved patient outcomes and quality of care in neurosurgical and neuroradiological practice.

Simultaneous Parkinsonism and Dementia as Initial Presentation of Intracranial Dural Arteriovenous Fistulas: A Systematic Review

BACKGROUND

Intracranial dural arteriovenous fistulas (IDAVFs) are abnormal vascular connections between dural arteries and various venous structures within the brain. IDAVFs, rarely present with parkinsonism and dementia concurrently, making this a unique and underexplored clinical scenario. To the best of our knowledge, this is the first systematic review to comprehensively analyze cases of IDAVFs manifesting as both parkinsonism and dementia.

METHODS

We assessed databases from inception to September 18, 2023. We identified studies describing patients with IDAVFs initially presenting with dementia or parkinsonism. Inclusion criteria encompassed case reports and case series, while excluding review articles, guidelines, technical notes, comments, conference abstracts, and editorials.

RESULTS

The systematic search resulted in the initial screening of 383 studies, with 33 articles meeting the inclusion criteria. Among these, 29 were case reports, often describing 3 or fewer patients. From the remaining 4 case series, data pertinent to patients presenting both parkinsonism and dementia were selectively extracted, yielding a total study population of 43 patients. The anatomical distribution of IDAVFs within this cohort was diverse, with the transverse and sigmoid sinuses being the most common locations. Although most of these patients received endovascular therapy, a few underwent microsurgical occlusion or combined surgical and endovascular treatment.

CONCLUSIONS

IDAVFs presenting with both parkinsonism and dementia represent a rare clinical entity. This systematic review provides valuable insights into the clinical characteristics, treatment options, and outcomes for such cases. However, additional research involving larger cohorts is essential to better comprehend the underlying mechanisms and establish standardized therapeutic guidelines.

Intracranial dural arteriovenous fistulas: association with cerebral venous thrombosis, baseline aggressiveness, and clinical outcomes. A retrospective multicenter study on 263 consecutive patients and literature review

OBJECTIVE

The pathogenesis of intracranial dural arteriovenous fistulas (icDAVFs) is controversial. Cerebral vein thrombosis (CVT) and venous hypertension are recognized predisposing factors. This study aimed to evaluate the incidence of association between icDAVF and CVT and describe baseline aggressiveness and clinical outcomes for icDAVFs associated with CVT. The authors also performed a literature review of studies reporting icDAVF associated with CVT.

METHODS

Two hundred sixty-three consecutive patients in two university hospitals with confirmed icDAVFs were included. A double-blind imaging review was performed to determine the presence or absence of CVT close or distant to the icDAVF. Location, type (using the Cognard classification), aggressiveness of the icDAVF, clinical presentation, treatment modality, and clinical and/or angiographic outcomes at 6 months were also collected. All prior brain imaging was analyzed to determine the natural history of onset of the icDAVF.

RESULTS

Among the 263 included patients, 75 (28.5%) presented with a CVT concomitant to their icDAVF. For 18 (78.3%) of 23 patients with previous brain imaging available, CVT preceding the icDAVF was proven (6.8% of the overall population). Former/active smoking (OR 2.0, 95% CI 1.079-3.682, p = 0.022) and prothrombogenic status (active inflammation or cancer/coagulation trouble) were risk factors for CVT associated with icDAVF (OR 3.135, 95% CI 1.391-7.108, p = 0.003). One hundred eighty-seven patients (71.1%) had a baseline aggressive icDAVF, not linked to the presence of a CVT (p = 0.546). Of the overall population, 11 patients (4.2%) presented with spontaneous occlusion of their icDAVF at follow-up. Seven patients (2.7%) died during the follow-up period. Intracranial DAVF + CVT was not associated with a worse prognosis (modified Rankin Scale score at 3-6 months: 0 [interquartile range {IQR} 0-1] for icDAVF + CVT vs 0 [IQR 0-0] for icDAVF alone; p = 0.055).

CONCLUSIONS

This was one of the largest studies focused on the incidence of CVT associated with icDAVF. For 6.8% of the patients, a natural history of CVT leading to icDAVF was proven, corresponding to 78.3% of patients with previous imaging available. This work offers further insights into icDAVF pathophysiology, aiding in identifying high-risk CVT patients for long-term follow-up imaging. Annual imaging follow-up using noninvasive vascular imaging (CT or MR angiography) for a minimum of 3 years after the diagnosis of CVT should be considered in high-risk patients, i.e., smokers and those with prothrombogenic status.

A contemporary analysis of surgical ligation versus endovascular embolization in patients with intracranial dural arteriovenous fistulas: a propensity score-matched and mixed-effects model study

OBJECTIVE

Intracranial dural arteriovenous fistulas (dAVFs) are rare vascular lesions that can be asymptomatic or can lead to devastating hemorrhage based on the dAVF's aggressiveness. Several approaches can be taken to treat dAVFs, such as endovascular embolization and surgical ligation. However, very few studies have evaluated the influence of surgery compared to endovascular approaches on patient outcomes. This study was performed to analyze the clinical characteristics and outcomes of patients who underwent treatment for intracranial dAVF in which either endovascular embolization or microsurgical ligation was used.

METHODS

The Nationwide Readmissions Database was reviewed for all patients who underwent treatment for dAVFs (n = 18,152) between 2016 and 2019. Patients who received only surgical ligation or endovascular embolization (i.e., not both) were included. Variables regarding demographics, clinical outcomes, and healthcare utilization were queried. Primary outcome measures were nonroutine discharge, 1-year readmission, top quartile length of stay (LOS), and top quartile of inpatient all-payer cost. Propensity score matching was performed to evaluate the influence of either surgery or embolization on patient outcomes. Receiver operating characteristic (ROC) curves were created for each outcome measure. The area under the curve (AUC) of each ROC was used to estimate mixed-effects model performance.

RESULTS

Following propensity score matching, 127 and 113 patients made up the surgical ligation and endovascular embolization cohort, respectively. There were no differences found in age (p = 0.16), sex (p = 0.57), or average Elixhauser Comorbidity Index (p = 0.32). Patients receiving surgical ligation had lower odds of readmission (OR 0.37, p = 0.028) and greater odds of nonroutine discharge (OR 2.21, p = 0.03) compared to patients who underwent endovascular embolization. The authors found no differences in the top quartile of LOS (p = 0.84), top quartile of cost (p = 0.38), or mortality (p > 0.99) between cohorts. ROC curves revealed that the mixed-effects models inclusive of approach outperformed models agnostic to approach with respect to nonroutine discharge (AUC with approach, 0.871; AUC without approach, 0.850; p = 0.018) and readmission (AUC with approach, 0.686; AUC without approach, 0.651; p = 0.019), but no differences were observed regarding top quartile of LOS (p = 0.17) and top quartile of cost (p = 0.40).

CONCLUSIONS

Surgical approach may influence perioperative outcomes in patients treated for intracranial dAVF-most significantly discharge disposition and 1-year readmission. Future longitudinal prospective studies with more clinical detail will be required to fully capture the predictive utility of surgical approach in patients treated for intracranial dAVF, particularly for various dAVF subtypes.

Microsurgical versus endovascular treatment of ethmoidal dural arteriovenous fistulas: systematic review and meta-analysis with a single-center case series

OBJECTIVE

Ethmoidal dural arteriovenous fistulas (DAVFs) are often associated with cortical venous drainage (CVD) and a higher incidence of hemorrhage compared with DAVFs in other locations. They may be treated with open surgical disconnection or with endovascular treatment (EVT). In this systematic review and meta-analysis, the authors compare the outcomes of ethmoidal DAVFs treated with open microsurgery versus EVT and report four additional cases of ethmoidal DAVFs treated with open microsurgery in their institution.

METHODS

A literature search of the PubMed and Scopus databases was conducted between December 2021 and May 2022 to identify relevant articles published between 1990 and 2021 using the PRISMA guidelines. References were reviewed and screened by two authors independently, and disagreements were resolved through consensus. Exclusion criteria included non-English-language studies, those with an incorrect study design, those reporting DAVFs in a nonethmoidal location, and studies whose outcomes were not stratified based on DAVF location. Inclusion criteria were any studies reporting on ethmoidal DAVFs treated by either microsurgery or EVT. A risk of bias assessment was performed using the Newcastle-Ottawa Scale. The authors performed a pooled proportional meta-analysis to compare patient outcomes.

RESULTS

Twenty studies were included for analysis. Of 224 patients, 142 were treated with surgery, while 103 were treated with EVT. Seventy percent (148/210) of the patients were symptomatic at presentation, with hemorrhage being the most common presentation (48%). CVD was present in 98% of patients and venous ectasia in 61%. The rates of complete DAVF obliteration with surgery and EVT were 89% and 70%, respectively (95% CI -30% to -10%, p < 0.03). Twenty percent (21/103) of endovascularly treated fistulas required subsequent surgery. Procedure-related complications occurred in 10% of the surgical cases, compared with 13% of the EVT cases. The authors' case series included 4 patients with ethmoidal DAVFs treated surgically with complete obliteration, without any postoperative complications.

CONCLUSIONS

The complete obliteration rates of ethmoidal DAVF appear to be higher and more definitive with microsurgical intervention than with EVT. While complication rates between the two procedures seem similar, patients treated with EVT may require further interventions for definitive treatment. The limitations of this study include its retrospective nature, the quality of studies included, and the continued evolving technologies of EVT. Future studies should focus on the association between venous drainage pattern and the proclivity toward venous ectasia or rate of hemorrhage at presentation.

Navigation guided small craniectomy and direct cannulation of pure isolated sigmoid sinus for treatment of dural arteriovenous fistula

Dural arteriovenous fistula (DAVF) is a rare condition affecting approximately 1.5% of 1,000,000 individuals annually. It frequently occurs in the transsigmoid and cavernous sinuses. An isolated sigmoid sinus is extremely rare and is treated by performing transfemoral transvenous embolization along the opposite transverse sinus. A 69-year-old woman presented with asymptomatic Borden type III/Cognard type III DAVF involving an isolated sigmoid sinus. She underwent a staged operation in which a navigation system was used to expose the sigmoid sinus in the operating room before transferring the patient to the angio suite for transvenous embolization. Various modalities have been used to treat DAVF, including surgical disconnection, transarterial embolization, transvenous embolization, and stereotactic radiosurgery. However, treating DAVF cases where the affected sinus is isolated can be challenging because an easily accessible surgical route may not be available. In this case, direct sinus cannulation and transvenous embolization were the most effective treatments.

Endovascular treatment strategy and clinical outcome of tentorial dural arteriovenous fistula

Introduction

To evaluate treatment strategies and clinical outcomes following endovascular embolization of tentorial dural arteriovenous fistulas.

Methods

We retrospectively analyzed 19 patients with tentorial dural arteriovenous fistulas admitted to the Department of Neurosurgery at Jiangsu Provincial People's Hospital between October 2015 and May 2022, all treated with endovascular therapy. To collect and analyze patients' clinical presentation, imaging data, postoperative complications, and prognosis and to analyze the safety and clinical outcomes of endovascular treatment of tentorial dural arteriovenous fistulas.

Results

Imaging cure was achieved in 18 patients, with the arterial route chosen for embolization in 17 patients and the venous route in one patient; one patient received partial embolization. Staged embolization was performed in four patients. At postoperative follow-up of 9-83 months (37.8 ± 21.2), all 19 patients had recovered well (mRS score ≤ 2). Three patients experienced perioperative complications: intraoperative Onyx reflux into the middle cerebral artery in one patient; postoperative permanent limited left visual field loss and deafness in the left ear in one patient; and transient diplopia, vertigo, and decreased pain and temperature sensation of the left limb in one patient, with no abnormalities on post-procedure magnetic resonance examinations. A total of 17 patients completed a postoperative digital subtraction angiography review during follow-up, and one patient had a recurrence of an arteriovenous fistula.

Conclusion

Endovascular treatment of tentorial dural arteriovenous fistulas is safe and effective. Reduction of the Borden or Cognard classification via eliminating cortical venous reflux through multi-staged embolization or combined open surgery is a reasonable goal of treatment where complete obliteration of the fistula is not achievable.

Severe papilledema and multiple hypercoagulability abnormalities in patient with dural arterio-venous fistulas

A 54-year-old man noticed right-sided pulsatile tinnitus for the past six months and recently started experiencing transient visual obscurations when standing up. MRI demonstrated two separate brain dural arteriovenous fistulas (bdAVF) in sagittal and right sigmoid dural sinuses. Neuro-ophthalmological exam demonstrated severe bilateral optic disc edema with preserved visual acuity but early nerve fiber bundle defects on visual field testing. Hypercoagulable profile testing revealed very elevated D-dimer, significantly decreased protein S level and elevated homocysteine levels. This case highlights importance of referring all patients with bdAVFs for neuro-ophthalmological consultation as venous hypertension can cause increased intracranial pressure and resultant papilledema. Papilledema does not affect central vision until late stages when visual loss is irreversible thus screening for its presence and pre-treatment extent of peripheral visual loss is paramount. It also demonstrates that hypercoagulable workup should be initiated in all patients with bdAVF in order to prevent future thromboembolic events.

Cognitive improvement following endovascular embolization in patients with intracranial dural arteriovenous fistula: The Neuropsychology in dural ArterIal Fistula (NAIF) Study

BACKGROUND

Cognitive improvement after endovascular embolization of an intracranial dural arteriovenous fistula (dAVF) remains unexplored. We aim to investigate cognitive changes following endovascular embolization of dAVFs.

METHODS

Neuropsychology in dural ArterIal Fistula (NAIF) was a prospective multicentric study including patients with an angiographic diagnosis of dAVF who underwent endovascular embolization over the course of 4 years. A complete neuropsychological evaluation comprising five cognitive domains (attention and executive functions, memory, language, praxis, gnosis) was performed at baseline and 3 months follow-up. Mean Z scores for cognitive tests were compared pre- and post-treatment using paired sample t-tests, where higher Z scores indicate better cognition. Effect sizes were computed as Cohen's d.

RESULTS

A total of 32 patients (mean age 61.1±15.4 years, 10 (31.3%) females) were included. Patients exhibited improved performance in attention and executive functions: executive functions-attention (+0.282, P=0.009, d=0.29), executive functions-fluencies (+0.283, P=0.029, d=0.4), and executive functions-processing speed (+0.471, P=0.039, d=0.41). There was an increase in memory: verbal learning and verbal delayed recall scores (+0.513, P<0.001, d=0.55, and +0.385, P=0.001, d=0.41, respectively), while verbal recognition parameters (+0.839, P=0.086, d=0.37) and visual memory (delayed recall) (+0.430, P=0.060, d=0.35) displayed trends toward improved performance. Regarding language, there was significant overall improvement (+0.300, P=0.014, d=0.24), but neither praxis nor gnosis changed significantly. These cognitive outcomes were independent of the severity (measured as Cognard classification), and no patient experienced cognitive worsening.

CONCLUSION

This study suggests that endovascular embolization confers cognitive benefits on dAVF patients undergoing endovascular embolization and may be beneficial even for patients with a low risk of hemorrhage.

Dural arteriovenous fistula with spinal dural arteriovenous fistula: a case report and review of the literature

BACKGROUND

This paper analyzed the cases of dural arteriovenous fistula (DAVF) with spinal dural arteriovenous fistula (SDAVF) in the diagnosis and treatment process.

CASE PRESENTATION

One case involving dural arteriovenous fistula (DAVF) with spinal dural arteriovenous fistula (SDAVF) from the 306th Hospital of PLA was retrospectively analyzed. The patient consulted the doctor due to lower limb sensory and motor disorders while exhibiting symptoms of urinary dysfunction. A computed tomographic angiography (CTA) and cerebral angiography confirmed the diagnosis of dural arteriovenous fistula (DAVF), necessitating surgical treatment. The patient was referred to our hospital for an magnetic resonance imaging (MRI) and a spinal angiography to obtain a confirmed diagnosis for spinal arteriovenous fistula, after which they underwent surgical fistula resection. The invasive intracranial dural arteriovenous fistula (DAVF) resection proceeded smoothly but did not ease the patient's symptoms. However, postoperative symptoms were partially relieved by the lumbar open spinal dural arteriovenous fistula adminstration.

CONCLUSIONS

Since not enough is understood about these two diseases, the rate of misdiagnosis is significantly increased. Early diagnosis and treatment of spinal dural arteriovenous fistula (SDAVF) can play a positive role during the recovery from neural function damage.

Secondary ocular hypertension due to tentorial dural arteriovenous fistula: a case report

BACKGROUND

Tentorial dural arteriovenous fistulas (TDAVFs) are abnormal shunts between meningeal arteries and the intradural venous system located in the tentorial dura mater, which typically manifest with haemorrhage or progressive neurological disorders. TDAVFs with pure ocular presentation have been rarely reported.

CASE PRESENTATIONS

The case of a 56-year-old man presented with unilateral eye redness, proptosis and elevated intraocular pressure was reported herein, which was caused by a TDAVF. The fistula was fed by the left posterior cerebral artery and posterior meningeal artery. The drainage was into the basal vein and internal cerebral veins, which led the arterial blood flow forward to the left superior ophthalmic vein directly. The redundant blood flow caused the rise of episcleral venous pressure, leading to the clinical presentations. Gamma knife radiosurgery was performed then considering the delicate vascular structure and its deep location. The corkscrew hyperaemia was gradually alleviated after the surgery, but the intraocular pressure remained elevated at follow-ups.

CONCLUSION

Dural arteriovenous fistulas which are not directly connected to cavernous sinus could cause ocular presentations like proptosis, eye redness and ocular hypertension.

Clinical characteristics and outcome of dural arteriovenous fistulas secondary to cerebral venous sinus thrombosis: a primary or secondary event?

BACKGROUND

The Dural Arteriovenous Fistulas (DAVFs) secondary to cerebral venous sinus thrombosis (CVST) are rather rare. The aim of present study is to investigate the clinical and radiological features, and treatment outcome of DAVFS in patients following CVST.

METHODS

Data about demographic information, clinical presentations, radiological findings, as well as treatment and outcome of DAVFs sequence to CVST were collected to analysis from January 2013 to September 2020 in this retrospective study.

RESULTS

Fifteen patients with DAVFs after CVST were included in the study. The median age was 41 years (range17-76 years). Ten patients (66.67%) were male and 6 patients (33.33%) were female. The median duration of presenting CVST was 182 days (Range 20-365). Mean time from diagnosis of CVST to confirmation of DAVFs was 97 days (range 36-370 days). The most common manifestations of DAVFs following CVST were headache and visual disturbance seen in 7 patients respectively. Five patients had pulsatile tinnitus (%) and 2 had nausea/vomiting. The DAVFs are most frequently located at the transverse/sigmoid sinus (7/15, 46.67%), followed by the superior sagittal the sinus and confluence sinus (6/15, 40.00%) respectively. Angiography of DAVFs revealed Board type I in seven (46.7%) patients, Board type II and III in 4(26.7%) patients, respectively. The Cognard I was noted in seven (46.7%), Cognard IIa and IV in 3 patients, IIb and III in one patient, respectively. The main feeding arteries of DAVFs most commonly originate from the branches of the external carotid artery in 6 (40.0%) patients. The other DAVFs are conjointly supplied by multiple feeders from internal and external carotid artery and vertebral arteries. Fourteen (93.33%) patients were treated with endovascular embolization and none of the patients had permanent deficits during follow-up.

CONCLUSION

Intracranial DAVFs following CVST are rare presentations. Most patients have a good outcome after timely interventional therapy. Continued observation and follow-up of (DSA) are important to find DAVFs secondary to CVST.

Shaping the brain vasculature in development and disease in the single-cell era

The CNS critically relies on the formation and proper function of its vasculature during development, adult homeostasis and disease. Angiogenesis - the formation of new blood vessels - is highly active during brain development, enters almost complete quiescence in the healthy adult brain and is reactivated in vascular-dependent brain pathologies such as brain vascular malformations and brain tumours. Despite major advances in the understanding of the cellular and molecular mechanisms driving angiogenesis in peripheral tissues, developmental signalling pathways orchestrating angiogenic processes in the healthy and the diseased CNS remain incompletely understood. Molecular signalling pathways of the 'neurovascular link' defining common mechanisms of nerve and vessel wiring have emerged as crucial regulators of peripheral vascular growth, but their relevance for angiogenesis in brain development and disease remains largely unexplored. Here we review the current knowledge of general and CNS-specific mechanisms of angiogenesis during brain development and in brain vascular malformations and brain tumours, including how key molecular signalling pathways are reactivated in vascular-dependent diseases. We also discuss how these topics can be studied in the single-cell multi-omics era.

Multimodal MRI diagnosis and transvenous embolization of a basicranial emissary vein dural arteriovenous fistula: A case report

A dural arteriovenous fistula (DAVF) is an abnormal linkage connecting the arterial and venous systems within the intracranial dura mater. A basicranial emissary vein DAVF drains into the cavernous sinus and the ophthalmic vein, similar to a cavernous sinus DAVF. Precise preoperative identification of the DAVF location is a prerequisite for appropriate treatment. Treatment options include microsurgical disconnection, endovascular transarterial embolization (TAE), transvenous embolization (TVE), or a combination thereof. TVE is an increasingly popular approach for the treatment of DAVFs and the preferred approach for skull base locations, due to the risk of cranial neuropathy caused by dangerous anastomosis from arterial approaches. Multimodal magnetic resonance imaging (MRI) can provide anatomical and hemodynamic information for TVE. The therapeutic target must be precisely embolized in the emissary vein, which requires guidance via multimodal MRI. Here, we report a rare case of successful TVE for a basicranial emissary vein DAVF, utilizing multimodal MRI assistance. The fistula had vanished, pterygoid plexus drainage had improved, and the inferior petrosal sinus had recanalized, as observed on 8-month follow-up angiography. Symptoms and signs of double vision, caused by abduction deficiency, disappeared. Detailed anatomic and hemodynamic assessment by multimodal MRI is the key to guiding successful diagnosis and treatment.

Multidisciplinary management of posterior fossa dural arteriovenous fistula: A single-center experience

PURPOSE

The management of posterior fossa dural arteriovenous fistulas (pfDAVFs) is challenging. Here, we show how multidisciplinarity leads to their successful management, even in complex cases.

METHODS

All pfDAVFs managed from 2010 to 2019 at our center were reviewed. The preoperative clinical and radiological characteristics, their management and the occlusion rate were retrieved. The radiological and functional outcomes were retrieved at discharge and last follow-up (FU).

RESULTS

n=27 patients were included (6 females, mean age: 61-years-old, mean FU: 22.5 months). n=8 patients presented with cerebral hemorrhage. Among patients with ruptured pfDAVFs, n=7 had headache, n=4 had ataxia, and n=2 had impaired level of consciousness. In the unruptured group N (n=19), n=7 patients had headache, n=6 patients had focal neurological deficit, n=4 patients had tinnitus, n=3 (had ataxia, and one presented with seizure. n=24 patients were treated by endovascular therapy (EVT), n=2 patients were treated by microsurgery (MS) and n=1 patient was managed with a combined approach. Re-treatment was necessary in n=6 patients. n=24 patients showed total exclusion at last FU. n=2 patients died during the first 30 days; n=1 patient died during FU.

CONCLUSIONS

While EVT should be advocated as the first line therapy whenever possible, MS should not be banned from the treatment armamentarium. Neurosurgeons must be able to achieve direct surgical occlusion when the angioarchitecture speaks against EVT.

Reversible Dementia With Bilateral White Matter Changes Caused by Dural Arteriovenous Fistula: Case Report and Review of the Literature

INTRODUCTION

Dural arteriovenous fistula (DAVF) is a vascular malformation. Although rare, DAVFs can represent a potentially reversible cause of dementia. Bilateral white matter changes can be detected on the magnetic resonance imaging of patients with DAVFs. Familiarity with symptoms of DAVFs can reduce the incidence of misdiagnosis of dementia syndrome. This study aimed to explore the clinical manifestation, imaging characteristics, and prognosis of dementia with bilateral white matter changes caused by DAVFs.

CASE REPORT

A 56-year-old man presented with memory deterioration, tinnitus, and weakness in both lower limbs for over 2 months. Magnetic resonance imaging of the brain revealed white matter signal changes in the bilateral ventricles and centrum semiovale, which manifested as low signal on T1-weighted imaging, high signal on T2-weighted imaging, fluid-attenuated inversion recovery, and diffusion-weighted imaging. Digital subtraction angiography revealed DAVFs along the lateral sinus. The patients' condition improved significantly after endovascular embolization of the DAVFs.

CONCLUSIONS

DAVFs presenting with dementia are rare and cases with bilateral white matter alterations can be easily misdiagnosed as other diseases. If the patient has dementia and bilateral alterations in the white matter, a DAVF should be considered. This type of dementia is reversible and may be associated with venous hypertension caused by arteriovenous fistulas. Early digital subtraction angiography is important to reduce misdiagnoses.

[Cerebral dural arteriovenous fistulas]

CLINICAL ISSUE

The cerebral dural arteriovenous (AV) fistula is a rare cerebral vascular malformation. Clinical presentation varies from asymptomatic to acute intracranial bleeding. Classification is based on the venous drainage with a risk assessment of bleeding. The carotid-cavernous fistula is a subtype with its own classification and treatment approaches.

PRACTICAL RECOMMENDATIONS

Nowadays, dural fistulas can be diagnosed using high-resolution and time-resolved tomographic methods. Catheter angiography with subsequent interdisciplinary discussion should be performed for precise classification and therapy planning. Both endovascular and surgical treatment methods are available.

Pathophysiology and classification of intracranial and spinal dural AVF

Dural arteriovenous fistulas (DAVFs) are pathologic shunts between pachymeningeal arteries and dural venous channel. DAVFs are relatively rare, however, DAVFs can lead to significant morbidity and mortality due to intracranial hemorrhage and non-hemorrhagic neurologic deterioration related to leptomeningeal venous drainage. The etiology and pathophysiology of DAVFs is not fully understood. Several hypotheses for development of DAVF and classifications for predicting risk of hemorrhage and neurological deficit have been proposed to help clinical decision making according to its natural history. Herein, incidence, etiology, pathophysiology of development of intracranial and spinal DAVF including their classifications are briefly described with short historical review.

Coexistence of anterior cranial fossa dural arteriovenous fistula and arteriovenous malformation with the same drainage system: illustrative case

BACKGROUND

The authors report a rare case of coexistence of dural arteriovenous fistula (DAVF) and arteriovenous malformation (AVM), with a common trunk drainer from both DAVF and AVM in the left anterior cranial fossa (ACF) with simple DAVF in the right ACF.

OBSERVATIONS

A 63-year-old female presented with seizure. Cerebral angiography showed bilateral DAVFs in the ACF and AVM in the left frontal lobe. A dilated frontal vein acted as a simple drainer of the right DAVF. In contrast, a dilated vein with large varix was the common drainer of both the left DAVF and the AVM. During surgery, indocyanine green videoangiography was performed with direct observation. In the left ACF, the drainer occlusion of the DAVF resulted in partial shrinkage of the varix and decreased distal blood flow. Additional main feeder occlusion of the AVM could decrease the blood flow further, but not completely because of the residual pial supplies for the AVM. Finally, the nidus of the AVM with varix was removed by en bloc resection.

LESSONS

Neurosurgeons should be aware of the coexistence of DAVF and AVM with a common trunk drainer. Only simple occlusion of the drainer from DAVF is not sufficient, so removal of the AVM is essential.

Endovascular Management of Intracranial Dural AVFs: Principles

Intracranial dural AVFs are abnormal communications between arteries that supply the dura mater and draining cortical veins or venous sinuses. They are believed to form as a response to venous insults such as thrombosis, trauma, or infection. Classification and management are dependent on the presence of drainage/reflux into cortical veins because such drainage markedly elevates the risk of hemorrhage or venous congestion, resulting in neurologic deficits. AVFs with tolerable symptoms and benign drainage patterns can be managed conservatively. Intolerable symptoms, presentation with hemorrhage/neurologic deficits, or aggressive drainage patterns are indications for intervention. Treatment options include microsurgical disconnection, endovascular transarterial embolization, transvenous embolization, or a combination. This is the first in a series of 3 articles on endovascular management of intracranial dural AVFs, in which we outline the principles and outcomes of endovascular treatment.

Onyx Embolization of an Indirect Carotid–Cavernous Fistula with Cortical Venous Reflux: Technical note

Background Indirect carotid–cavernous fistulas (iCCFs) are shunts between meningeal branches of the internal carotid and/or the external carotid arteries and the cavernous sinus. They account for 83% of all carotid–cavernous fistulas (CCFs). Symptomatic iCCFs and those with increased risk of hemorrhage should be treated. Transvenous endovascular treatment is the preferred treatment modality. However, in complex cases, a combination of transarterial and transvenous approaches (multimodal treatment) is required.

Methods A middle-aged woman presented with signs of increased intraocular pressure, blurry vision, diplopia, left proptosis, chemosis, conjunctival injection, ptosis, and cranial nerve VI palsy. Imaging confirmed the presence of a Barrow type D and Thomas type 4 iCCF with cortical venous reflux (CVR).

Results The patient underwent transarterial and transvenous onyx embolization of the shunt, achieving a complete obliteration of the fistula. No complications occurred and the patient had a satisfactory postprocedural evolution.

Conclusion Multimodal onyx embolization is an effective option for the treatment of a complex symptomatic iCCF. If CVR is identified, these lesions should be promptly treated to prevent hemorrhage secondary to rupture.

Vascular intracranial malformations and dementia: An under-estimated cause and clinical correlation. Clinical note

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Cerebrovascular malformations (CVMs) such as arteriovenous malformations (AVMs) or dural arteriovenous fistulas (DAVFs) in addition to hemorrhagic presentation or focal neurological deficit, may manifest with global brain dysfunction resulting in dementia.

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Dementias secondary to CVMs constitute a probably underestimated subpopulation of patients of great interest because they present with devastating but potentially reversible cognitive impairment.

Cerebrovascular malformations (CVMs) such as arteriovenous malformations (AVMs) or dural arteriovenous fistulas (DAVFs) represent a possible source of intracranial hemorrhage, but these malformations can also manifest with neurologic disorders secondary to ischemic penumbra from vascular steal. In the latter case, the clinical manifestations are less obvious and characteristic, and may include a varied clinical spectrum ranging from focal deficits to generalized malfunction of the brain parenchyma resulting in dementia. Dementias secondary to CVMs constitute a probably underestimated subpopulation of patients of great interest because they present with devastating but potentially reversible cognitive impairment. We examined the pertinent literature regarding the clinical manifestations of CVMs characterized by cognitive impairment and describe the distinctive clinical features. Our results confirm that cognitive impairment is one of the clinical manifestations of CVMs and is a frequently misrecognized and often late-diagnosed cause of reversible dementia.

Rapidly progressive dementia and Parkinsonism as the first symptoms of dural arteriovenous fistula. The Sapienza University experience and comprehensive literature review concerning the clinical course of 102 patients

BACKGROUND

Dementia is a chronic loss of neurocognitive function that is progressive and irreversible. Dural arteriovenous fistulas (DAVFs) are acquired lesions that account for 10-15% of intracranial vascular malformations that could present with a rapid decline in neurocognitive function with or without Parkinson-like symptoms and evolve in a rapidly progressive dementia (RPD). Often the DAVFs are not even included in the differential hypotheses of this type of dementia and are not present in any type of diagnostic algorithm for evaluating RPD.

METHODS

We performed a systematic review of the international literature and adding the cases coming from our institutional experience and we have collected all the reported cases of DAVFs that debut with ROD identifying the most frequent forms in terms of location and type, reporting the neurological characteristics and the outcome of each patient.

RESULTS

The exact pathogenesis for developing dementia in patients with DAVFs remains largely unknown. The imaging changes and pathologic findings support the hypothesis that the clinical course results from the delivery of excessive volumes of blood flow into a venous system with outflow obstruction and venous congestion. The large variety of clinical manifestations of DAVFs depends on its location but this is not exactly valid for the onset of dementia. It supposed that the highly variable clinical manifestation of DAVFs has been convincingly related to the pattern of venous drainage more than location.

CONCLUSIONS

Neurologists and clinicians generally are familiar with the differential diagnoses of slowly progressive neurodegenerative dementias, but the diagnosis of RPD entails a different diagnostic approach. Due to their curable nature, the diagnosis of DAVFs must be suspected when facing a RPD picture, even more so if it is associated with characteristic abnormalities of the hemispheric white matter.

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. Cases were analyzed for demographics, clinical presentation, angiographic findings, treatment techniques, angiographic and clinical outcomes, and complications.

RESULTS

Of 317 patients with DAVFs, 20 (6.3%) with an isolated sinus DAVF underwent treatment. Transarterial embolization was performed through the middle meningeal artery in 9 of 12 procedures, with a success rate of 66.7%. Transarterial glue embolization proved successful in two of five procedures (40%) and Onyx in six of seven procedures (85.7%). Transvenous embolization (TVE) with navigation via the occlusion into the isolated sinus was successful in seven out of nine procedures (77.8%). All three open TVE and one pure open surgical procedure gained complete closure of the fistula. There were two major complications. Complete occlusion of the fistula was eventually obtained in all cases (100%).

CONCLUSIONS

Isolated sinus DAVFs are always aggressive and require a multimodal approach to guarantee closure of the shunt. Transarterial treatment with Onyx achieves good results. Transvenous treatment appears equally successful, navigating into the occluded segment across the occlusion or via burr hole as backup.

Changes in Angioarchitecture After Stereotactic Radiosurgery for Dural Arteriovenous Fistula

INTRODUCTION

Dural arteriovenous fistulae (DAVF) are intracranial vascular abnormalities encountered in neurosurgery practice. Treatment options are microsurgical disconnection, endovascular embolization and/or radiosurgery. Past studies have reported the efficacy, safety, and predictors of success of radiosurgery. In this study, we investigated the angioarchitecture of fistulae at the time of radiosurgery and how the anatomy changed in the time after treatment based on angiogram follow-ups.

METHODS

A retrospective analysis was performed on patients with angiographic diagnosis of DAVF treated with Gamma Knife radiosurgery (GKRS) between 2013 and 2018. Data collection included demographics, symptoms, grading scores, vascular anatomy, radiation data, treatment strategy, angiographic results, and length of patient follow-up.

RESULTS

Our study reports data on 10 patients with a total of 14 fistulae. On follow-up angiography, 8 (57%) had complete occlusion of the fistula with a median time to follow up of 19.5 months. The remaining 6 (43%) were deemed as near-complete occlusion of fistula with a median time to follow up of 12.0 months. Time from radiosurgery to angiogram revealing incomplete vs. angiogram revealing complete obliteration was significantly different (p=0.045). Nearly all AVFs had decreased feeders over time after treatment with only one AVF developing an additional feeder post-treatment. Arterial feeders, drainage site, sex, Borden type, lesion volume and treatment volume had no predictive value of obliteration outcome.

CONCLUSIONS

This study provides data on the angioarchitecture of fistulae treated with GKRS and also serves as an extension of previous studies reporting the safety and efficacy of GKRS treatment for DAVF in a specific patient population.

Onyx embolization for dural arteriovenous fistulas: a multi-institutional study

BACKGROUND

Although the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate its performance.

OBJECTIVE

To carry out a multicenter study to determine the predictors of complications, obliteration, and functional outcomes associated with primary Onyx embolization of DAVFs.

METHODS

From the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database, we identified patients who were treated for DAVF with Onyx-only embolization as the primary treatment between 2000 and 2013. Obliteration rate after initial embolization was determined based on the final angiographic run. Factors predictive of complete obliteration, complications, and functional independence were evaluated with multivariate logistic regression models.

RESULTS

A total 146 patients with DAVFs were primarily embolized with Onyx. Mean follow-up was 29 months (range 0-129 months). Complete obliteration was achieved in 80 (55%) patients after initial embolization. Major cerebral complications occurred in six patients (4.1%). At last follow-up, 84% patients were functionally independent. Presence of flow symptoms, age over 65, presence of an occipital artery feeder, and preprocedural home anticoagulation use were predictive of non-obliteration. The transverse-sigmoid sinus junction location was associated with fewer complications, whereas the tentorial location was predictive of poor functional outcomes.

CONCLUSIONS

In this multicenter study, we report satisfactory performance of Onyx as a primary DAVF embolic agent. The tentorium remains a more challenging location for DAVF embolization, whereas DAVFs located at the transverse-sigmoid sinus junction are associated with fewer complications.

The Top-100 most cited articles on dural arteriovenous fistula: A bibliometric analysis

Objective

Dural arteriovenous fistula (DAVF) is a rare pathological vascular lesion with variable clinical manifestations. Since 1968, several articles have been published to address spinal and cranial DAVFs. The aim of this study is to identify, analyse, and review the pertinent literature of the top-100 most cited articles on DAVFs published to date.

Methods

A title-specific, keyword-based search with no time restriction was performed in June 2020. The Scopus database was used to identify the top-100 most cited articles on DAVFs. The term “dural arteriovenous fistula” was used as a search keyword. The search results were arranged in descending order based on the total citation count. The top-100 articles were categorized into ten categories.

Results

Between 1968 and 2020, a total of 2298 articles were published on DAVFs. The top-100 most cited articles were published between 1983 and 2012. The total number of citations for the top-100 articles was 12393 (123 citations/article). Most articles (34%) were investigating the clinical aspect of DAVFs. The country contributing to the most impactful and highest volume of publications (46%) was the United States. The Mayo Clinic was the most active institute in contribution. Most articles (29%) were published by the Journal of Neurosurgery.

Conclusions

In the top-100 most cited articles on DAVF, most studies were published in neurosurgery/neuroradiology-dedicated journals. This bibliometric analysis identifies the publication trends and provides a comprehensive overview of the most influential articles addressing DAVFs.

Direct transcranial coil and Onyx embolization of a dural arteriovenous fistula: Technical note and brief literature review

Intracranial high-grade dural arteriovenous fistulas (DAVFs) have higher bleeding rates compared to other intracranial vascular malformations. Endovascular treatment is usually recommended for high-grade lesions, aiming at a complete fistula obliteration. However, some patients have vascular abnormalities that limit endovascular access to the precise location of the shunt. Alternative techniques may be considered in this scenario. A middle-aged man presented with intracranial hypertension secondary to a high-grade DAVF. Because of vascular abnormalities precluding transvenous access to the intracranial venous circulation, the patient required treatment by a direct transcranial coil and Onyx embolization of the shunt. Direct transcranial cannulation of a dural sinus is an alternative and effective route for transvenous embolization of DAVFs, especially if abnormal venous anatomy precluding venous access to the required cranial venous system is identified.

Dural Arteriovenous Fistulae After Cerebral Venous Thrombosis

BACKGROUND AND PURPOSE

This analysis examined the frequency of dural arteriovenous fistulae (dAVF) after cerebral venous thrombosis (CVT) in patients included in a randomized controlled trial comparing dabigatran etexilate with dose-adjusted warfarin (RE-SPECT CVT [A Clinical Trial Comparing Efficacy and Safety of Dabigatran Etexilate With Warfarin in Patients With Cerebral Venous and Dural Sinus Thrombosis]), who had systematic follow-up magnetic resonance (MR) imaging.

METHODS

RE-SPECT CVT was a Phase 3, prospective, randomized, parallel-group, open-label, multicenter, exploratory trial with blinded end point adjudication. We allocated patients with acute CVT to dabigatran 150 mg twice daily or dose-adjusted warfarin, for 24 weeks and obtained a standardized MR protocol including time-of-flight MR angiography, 3-dimensional phase-contrast venography, and 3-dimensional contrast-enhanced MR venography at the end of the treatment period. A blinded adjudication committee assessed the presence of dAVF in a predefined substudy of the trial.

RESULTS

We analyzed development of dAVF in 112 of 120 randomized patients; 57 allocated to dabigatran and 55 to warfarin. For 3 (2.7%) of these 112 patients, quality of follow-up imaging was insufficient to evaluate dAVF. A dAVF (Borden I) was found in 1 patient (0.9%) allocated to warfarin; however, this dAVF was already present at baseline. The patient did not present with hemorrhage at baseline or during the trial and was asymptomatic at follow-up.

CONCLUSIONS

Despite systematic imaging, we found no new dAVF 6 months after CVT. Routine follow-up cerebral MR angiography aiming to detect new dAVF 6 months after CVT has a very low yield. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02913326.

Dural arteriovenous fistula is a rare cause of a pulsating noise in the ear (clinical observation and literature review)

The article describes the clinical manifestations of dural arteriovenous fistula, which is an abnormal communication between the arteries of the dura mater and venous sinuses or cortical veins. Information on the etiology and pathogenesis of such malformation in domestic literature is limited to a few publications. Diagnosis is based on the identification of visual (pulsation of the earlobe) and acoustic phenomena in the patient, the presence of neuroimaging, in particular MR angiography, a shunt between the posterior auricular artery (branch of the external carotid artery) and the dural venous sinuses. The best treatment method is neurosurgical intervention using endovascular surgery.

Microsurgical Anatomy of the Meningeal Branch of the Dorsolateral Medullary Plexus

BACKGROUND

Meningeal branches originating from intradural arteries may be involved in several diseases such as meningeal tumors and arteriovenous lesions. These "pial-dural" arterial connections have been described for anterior cerebral, posterior cerebral, and cerebellar arteries. However, to the best of our knowledge, meningeal supply originating from the arterial plexus over the dorsolateral aspect of the medulla oblongata (dorsolateral medullary plexus [DLMP]) has not been described.

OBJECTIVE

To define the microsurgical anatomy of the meningeal branch of DLMP.

METHODS

A total of 20 cadaver heads (40 sides) underwent far-lateral craniotomy and the cerebellomedullary cisterns were explored to find the DLMP and any meningeal branches. Additionally, de-identified intraoperative images of 85 patients with vertebral artery (VA)/posterior inferior cerebellar artery aneurysms who had undergone far-lateral craniotomy were studied to find any meningeal branches of DLMP.

RESULTS

The meningeal branches of DLMP were identified in 4 cadavers/sides. These branches reached the region of jugular tubercle (JT) after crossing the accessory nerve. In 3 specimens, these branches were joined by a small twig from V4-VA before penetrating the dura. DLMP meningeal branches were found in 12 patients of the studied cohort (14%) with similar anatomical features as those found in the cadaveric study.

CONCLUSION

DLMP may give rise to meningeal branches to the adjacent dura of JT. The actual prevalence of this anatomic variation is difficult to estimate using our data. However, when present, these branches may have important clinical implications, ie, diseases such as dural arteriovenous fistulas, pial arteriovenous malformations (AVMs), and meningeal-based tumors.

Hemorrhage risk of cerebral dural arteriovenous fistulas following Gamma Knife radiosurgery in a multicenter international consortium

OBJECTIVE

The authors performed a study to evaluate the hemorrhagic rates of cerebral dural arteriovenous fistulas (dAVFs) and the risk factors of hemorrhage following Gamma Knife radiosurgery (GKRS).

METHODS

Data from a cohort of patients undergoing GKRS for cerebral dAVFs were compiled from the International Radiosurgery Research Foundation. The annual posttreatment hemorrhage rate was calculated as the number of hemorrhages divided by the patient-years at risk. Risk factors for dAVF hemorrhage prior to GKRS and during the latency period after radiosurgery were evaluated in a multivariate analysis.

RESULTS

A total of 147 patients with dAVFs were treated with GKRS. Thirty-six patients (24.5%) presented with hemorrhage. dAVFs that had any cortical venous drainage (CVD) (OR = 3.8, p = 0.003) or convexity or torcula location (OR = 3.3, p = 0.017) were more likely to present with hemorrhage in multivariate analysis. Half of the patients had prior treatment (49.7%). Post-GRKS hemorrhage occurred in 4 patients, with an overall annual risk of 0.84% during the latency period. The annual risks of post-GKRS hemorrhage for Borden type 2-3 dAVFs and Borden type 2-3 hemorrhagic dAVFs were 1.45% and 0.93%, respectively. No hemorrhage occurred after radiological confirmation of obliteration. Independent predictors of hemorrhage following GKRS included nonhemorrhagic neural deficit presentation (HR = 21.6, p = 0.027) and increasing number of past endovascular treatments (HR = 1.81, p = 0.036).

CONCLUSIONS

Patients have similar rates of hemorrhage before and after radiosurgery until obliteration is achieved. dAVFs that have any CVD or are located in the convexity or torcula were more likely to present with hemorrhage. Patients presenting with nonhemorrhagic neural deficits and a history of endovascular treatments had higher risks of post-GKRS hemorrhage.

Evaluation of stereotactic radiosurgery for cerebral dural arteriovenous fistulas in a multicenter international consortium

OBJECTIVE

In this multicenter study, the authors reviewed the results obtained in patients who underwent Gamma Knife radiosurgery (GKRS) for dural arteriovenous fistulas (dAVFs) and determined predictors of outcome.

METHODS

Data from a cohort of 114 patients who underwent GKRS for cerebral dAVFs were compiled from the International Gamma Knife Research Foundation. Favorable outcome was defined as dAVF obliteration and no posttreatment hemorrhage or permanent symptomatic radiation-induced complications. Patient and dAVF characteristics were assessed to determine predictors of outcome in a multivariate logistic regression analysis; dAVF-free obliteration was calculated in a competing-risk survival analysis; and Youden indices were used to determine optimal radiosurgical dose.

RESULTS

A mean margin dose of 21.8 Gy was delivered. The mean follow-up duration was 4 years (range 0.5-18 years). The overall obliteration rate was 68.4%. The postradiosurgery actuarial rates of obliteration at 3, 5, 7, and 10 years were 41.3%, 61.1%, 70.1%, and 82.0%, respectively. Post-GRKS hemorrhage occurred in 4 patients (annual risk of 0.9%). Radiation-induced imaging changes occurred in 10.4% of patients; 5.2% were symptomatic, and 3.5% had permanent deficits. Favorable outcome was achieved in 63.2% of patients. Patients with middle fossa and tentorial dAVFs (OR 2.4, p = 0.048) and those receiving a margin dose greater than 23 Gy (OR 2.6, p = 0.030) were less likely to achieve a favorable outcome. Commonly used grading scales (e.g., Borden and Cognard) were not predictive of outcome. Female sex (OR 1.7, p = 0.03), absent venous ectasia (OR 3.4, p < 0.001), and cavernous carotid location (OR 2.1, p = 0.019) were predictors of GKRS-induced dAVF obliteration.

CONCLUSIONS

GKRS for cerebral dAVFs achieved obliteration and avoided permanent complications in the majority of patients. Those with cavernous carotid location and no venous ectasia were more likely to have fistula obliteration following radiosurgery. Commonly used grading scales were not reliable predictors of outcome following radiosurgery.

Factors Predicting De Novo Formation of Fistulas After Dural Fistula Embolization Using Venous Sinus Balloon Protection

BACKGROUND

Endovascular embolization with transvenous sinus preservation using balloon is at present the preferred modality for dural arteriovenous fistulas involving venous sinuses (sagittal, transverse, and sigmoid) with potential drainage function. The aim of the study was to evaluate the necessity and medium-term efficacy of this technique.

METHODS

Patients with dural arteriovenous fistulas involving large sinuses who underwent vascular embolization with transvenous balloon protection technique at our center from December 2012 to July 2017 were retrospectively reviewed. The clinical symptoms, postoperative and mid-term follow-up imaging results, perioperative complications, and follow-up clinical outcomes were analyzed.

RESULTS

Eighteen patients (8 women and 10 men) with mean age 49 years were included in this study. Complete (16 of 18) or near-complete (1 of 18) occlusion of original fistula was achieved in 17 patients (94.4%). Recurrence of original fistula (1 of 18) or de novo fistula (3 of 18) occurred in 4 patients (22.2%). The patency rate of balloon-protected sinus was 72.2% (13 of 18) during the follow-up, and the involved sinuses were eventually occluded in 5 patients (27.8%). The frequency of de novo fistulas was higher in patients with sinus occlusion (P < 0.05). Stenosis of the involved sinus was more likely related to balloon-protected sinus occlusion (P < 0.05). After a mean follow-up of 17.6 months, 17 patients (94.4%) achieved remission of the original symptoms.

CONCLUSIONS

Transvenous balloon protection technique maintains sinus patency in most cases, and preoperative stenosis increases the probability of sinus occlusion. De novo fistula is related to sinus occlusion during the follow-up.

Isolated subdural hematoma secondary to Dural arteriovenous fistula: a case report and literature review

Background

Dural arteriovenous fistula (DAVF) is an uncommon subtype among the intracranial arteriovenous malformations, which is characterized by pathological anastomoses between meningeal arteries and dural venous sinuses, meningeal veins, or cortical veins. While intracerebral hemorrhage accounts for most of the hemorrhagic cases in patients with DAVF, isolated subdural hematoma (SDH) is rarely reported.

Case presentation

A 45-year-old man was admitted for a progressively worsening headache over 2 weeks. Head computed tomography on admission revealed an isodense chronic SDH (CSDH) on the left hemisphere with mild midline shift. Further angiography of the external carotid artery revealed a DAVF at the transverse sinus. The DAVF was embolized via the middle meningeal artery. His CSDH gradually resolved without surgical intervention. In order to further elucidate this rare entity, a review of relevant literature was also conducted.

Conclusions

Isolated SDH is a rare complication of DAVF. In this report, we presented a rare case of CSDH secondary to an intracranial DAVF. According to this case report and our literature review, the so-called benign type of DAVF without cortical venous drainage does not always warrant a benign process and might be complicated with SDH. Careful preoperative investigation is needed for relative young patients presenting with idiopathic or atypical SDH.