Natural history, evaluation, and management of intracranial vascular malformations

The VEBAS score: a practical scoring system for intracranial dural arteriovenous fistula obliteration

BACKGROUND

Tools predicting intracranial dural arteriovenous fistulas (dAVFs) treatment outcomes remain scarce. This study aimed to use a multicenter database comprising more than 1000 dAVFs to develop a practical scoring system that predicts treatment outcomes.

METHODS

Patients with angiographically confirmed dAVFs who underwent treatment within the Consortium for Dural Arteriovenous Fistula Outcomes Research-participating institutions were retrospectively reviewed. A subset comprising 80% of patients was randomly selected as training dataset, and the remaining 20% was used for validation. Univariable predictors of complete dAVF obliteration were entered into a stepwise multivariable regression model. The components of the proposed score (VEBAS) were weighted based on their ORs. Model performance was assessed using receiver operating curves (ROC) and areas under the ROC.

RESULTS

A total of 880 dAVF patients were included. Venous stenosis (presence vs absence), elderly age (<75 vs ≥75 years), Borden classification (I vs II-III), arterial feeders (single vs multiple), and past cranial surgery (presence vs absence) were independent predictors of obliteration and used to derive the VEBAS score. A significant increase in the likelihood of complete obliteration (OR=1.37 (1.27-1.48)) with each additional point in the overall patient score (range 0-12) was demonstrated. Within the validation dataset, the predicted probability of complete dAVF obliteration increased from 0% with a 0-3 score to 72-89% for patients scoring ≥8.

CONCLUSION

The VEBAS score is a practical grading system that can guide patient counseling when considering dAVF intervention by predicting the likelihood of treatment success, with higher scores portending a greater likelihood of complete obliteration.

Simultaneous bilateral application of the Scepter mini balloon microcatheter for occlusion of ethmoidal dural arteriovenous fistulas

Ethmoidal dural arteriovenous fistulas are a rare entity accounting for 10 % of all dAVFs.3-6 Haemorrhage occurs in up to 91 % of cases, which is a particularly high risk and warrants therapeutic intervention.8-9 Endovascular treatment for these fistulas using the conventional detachable microcatheter technique is associated with certain limitations and risks; 8.3 % rate of incomplete obliteration and an 8.3 % rate of complications. Complications include reflux of liquid embolic agent, posterior ischaemic optic neuropathy, acute visual loss, and small subdural haematoma secondary to a micro-perforation.8,10-12 We present our recent experience with the Scepter Mini Balloon Microcatheter for the endovascular treatment of ethmoidal dural arteriovenous fistulas in 3 patients, involving bilateral simultaneous inflation of the balloon. It demonstrates a novel application of this technology with good outcomes. It supports the use of this microcatheter in treating ethmoidal dural arteriovenous fistulas endovascularly, either as a first-line option or as an adjunct to surgery.

Management of a dural arteriovenous fistula versus arteriovenous malformation of the internal auditory canal with radiosurgery

We present a case of a 61-year-old male who presented with an 8-month history of left hypacusis, tinnitus, and gait imbalance. MRI showed a vascular lesion in the left internal auditory canal (IAC). Angiogram showed a vascular lesion filling from the ascending pharyngeal and anterior inferior cerebellar artery (AICA) with drainage into the sigmoid sinus suggestive of either a dural arteriovenous malformation (dAVF) vs arteriovenous malformation (AVM) of the IAC. The decision was made to operate to prevent risk of future hemorrhage [1-5]. Endovascular options were not as ideal given access transarterially through the AICA would be risky, access transvenously would be difficult and it was unclear whether this lesion was a dAVF or AVM. The patient underwent a retrosigmoid approach. A tuft of arterialized vessels surrounding CN7/8 was identified and no true nidus was found so it was thought that this lesion was a dAVF. The plan was to clip the arterialized vein as is normally done for dAVF. However, there was engorgement of the vascular lesion upon clipping of the arterialized vein indicating risk of rupture if the clip was left insitu. It was too risky to drill the posterior wall of the IAC to expose the fistulous point more proximally. As a result, 2 clips were placed on the AICA branches. Postoperative angiogram showed some slowing of the vascular lesion but it was still present. Given the AICA feeder, it was decided that this lesion was a dAVF with mixed features of an AVM and the decision was made to gamma knife the lesion 3 months postoperatively. Patient underwent gamma knife targeting the dura superior to the IAC with 18 Gy at the 50 % isodose line. At 2 years follow up, the patient's symptoms improved and he remained neurologically intact. Imaging revealed complete obliteration of the dAVF. This case illustrates the step by step management of a dAVF that mimicked a true pial AVM. The patient consented to the procedure and participating in this surgical video.

Venous Pathologies and Interventions of the Head

Intracranial venous pathologies are a historically underrecognized group of disorders that can have a devastating impact on patients. Despite advancements in peripheral venous disorders and arterial neurointerventions, intracranial venous pathologies have received comparatively little attention. Understanding the anatomy, physiology, clinical relevance, and treatment options of intracranial venous pathologies is fundamental to evolving therapies and research priorities. This article provides an overview of major intracranial venous pathologies, the respective pathophysiologies, and treatment options.

Bithalamic infarction in a tentorial dural artero-venous fistula and thalamic dementia: a case report and systematic review

PURPOSE

To report a case of bilateral thalamic infarction (BTI) presenting as progressive thalamic dementia due to a midline tentorial dAVF (TdAVF) and to provide a systematic review of the literature.

METHODS

We performed a systematic literature review of previously reported cases of bi-thalamic signal changes due to dAVF considering population characteristics, clinical presentation, imaging findings, treatments, and outcomes.

RESULTS

We found 29 papers from 1985 until 2021 describing 35 cases of BTI dAVF-related. We analysed 36 cases comprehensive of our case report. The mean age was 58.7 years (range 38-79), 91.6% were males (n=33). Most cases presented with a subacute syndrome. In 86.1% (n=31) of cases a TdAVF was found; 58.3% (n=21) were type 2 Borden-Shucart fistulas, the remaining were mostly type 3. In 80.5% (n=29), a thrombosed sinus was identified. 33.3% of cases (n=12) had bi-thalamic haemorrhages. Endovascular treatment was performed in 83.3% of cases (n=30). A total of 75% (n=27) of cases had a good recovery.

CONCLUSIONS

BTIs due to dAVFs may present with subacute symptoms overlapping with several differential diagnoses. Prompt identification at MRI, before venous drainage failure and bleeding, is crucial for a good prognosis.

Dural arteriovenous fistula causing reversible cognitive impairment

A previously independent 82-year-old woman presented with 5 months of worsening confusion, mobility and cognitive decline, with deficits in orientation, language and executive function. A cerebral dural arteriovenous fistula was identified and successfully embolised, after which her cognitive ability and independence dramatically improved. Although rare, a dural arteriovenous fistula may mimic a rapidly progressive dementia, but its early recognition and treatment can completely reverse the dementia.

Cerebellar cavernous angioma associated with developmental venous anomaly presenting as a cerebellopontine angle neoplasm in CT scan

Association of developmental venous anomaly (DVA) and cavernous malformation (CM) of the posterior fossa is rare. If bleeding occurs, it must be assigned to the CM. Developmental venous anomalies, considered as normal vascular variation, are rarely symptomatic. Indeed, the CMs are true malformations and have a high bleeding potential.

Adult dural arteriovenous fistulas in Galen region: More to be rediscovered

BACKGROUND

Dural arteriovenous fistulas (DAVFs) in the Galen region are the most deeply located and most complex type of dural arteriovenous fistulas. However, cases of DAVFs in this region have not been well described. Thus, we aimed to summarize the characteristics of Galenic DAVFs involving clinical symptoms, anatomical architecture, and drainage patterns, providing experientially therapeutic strategies for these lesions based on our 20 years of clinical experience.

METHODS

We retrospectively examined 31 patients with Galenic DAVFs between January 2000 and June 2021. A comprehensive analysis was carried out based on the symptoms, imaging features, feeding arteries, draining veins, number and location of the fistulas, choice of treatment methods, and prognosis assessment.

RESULTS

Twenty-nine patients received endovascular embolization, and no perioperative deaths occurred. A transarterial approach was performed in 27 patients, and a combined transarterial and transvenous approach in one. And in one case, access was established by surgical drilling and embolization was done via the venous route. Twenty-four cases were completely obliterated after first embolization, and another five cases received a second period treatment. Only one patient developed cognitive dysfunction after embolization, and the outcomes of the remaining patients were improved at long-term follow-up.

CONCLUSION

The understanding of symptoms of non-hemorrhagic neurological deficits in DAVF needs to be further clarified. Lesions with pial feeders may be considered first when determining surgical orders. Multi-approach and multi-stage embolization would be safe and effective. Excessive embolization and deep-vein system obstruction should be avoided. Approach creation by surgery would be an innovative interventional therapy.

Acquired dural arteriovenous fistula after cerebellopontine angle meningioma: A case report

RATIONALE

Intracranial brain surgeries, including ventriculostomy, burr hole, craniotomy, and craniectomy, are the most common causes of acquired dural arteriovenous fistula (dAVF). Here we report a case of acquired dAVF after a cerebellopontine angle meningioma surgery.

PATIENT CONCERNS

A 51-year-old woman was diagnosed with a 40-mm cerebellopontine angle meningioma. The patient underwent surgery via a retrosigmoid suboccipital approach. A small craniotomy and an additional craniectomy were performed. At 7 months after the surgery, she presented with pulsating tinnitus and headache.

DIAGNOSIS

Magnetic resonance imaging and digital subtraction angiography showed a dAVF that was fed by the occipital artery and drained into transverse and sigmoid sinuses.

INTERVENTIONS

We performed Onyx® (Irvine, CA) embolization.

OUTCOMES

The patient's symptoms completely improved.

LESSONS

Craniectomy defects, partially exposed sinuses, and incomplete cranioplasty might be risk factors for iatrogenic dAVF after a retrosigmoid suboccipital craniotomy or craniectomy. Complete reconstructive cranioplasty is an essential procedure to prevent a direct connection between the venous sinus and the external carotid artery.

Paleopathology of Endocranial Lesions: A Possible Case of a Middle Meningeal Artery Aneurysm in an Etruscan Child from Pontecagnano (Southern Italy)

A middle meningeal artery (MMA) aneurysm is a type of intracranial aneurysm that has been rarely documented and is not completely understood in clinical medicine and especially in pediatrics, because juvenile cases have been extremely uncommon. Vascular conditions have occasionally been diagnosed in osteoarchaeological remains, providing evidence of their occurrence in previous eras. In the present report, we have described a lesion that was highly consistent with a case of an MMA aneurysm observed in an Etruscan child, whose remains had been exhumed during archaeological excavations in the necropolis of Pontecagnano (Salerno, southern Italy). The remains date back to the seventh to sixth century BC. Macroscopic and radiological examinations revealed an oval depression in the endocranial area corresponding to the parietal branch of the right MMA. The localized thinning of the bone and the absence of a bone reaction were compatible with a long-lasting compression of vascular origin highly consistent with an MMA aneurysm. Primary malignant bone tumors, bone metastasis, benign neoplastic conditions, and other non-neoplastic conditions, including calvarial venous malformations, eosinophilic granuloma, and sarcoidosis, could be excluded from the differential diagnosis, although the occurrence of other pathologies, such as dural arteriovenous fistulas, could not be rejected. Although it was not possible to definitely establish whether the MMA aneurysm was symptomatic, it could not be ruled out that rupture and subsequent extradural hemorrhage and/or intracranial hemorrhage could have caused the death of the child. From a paleopathological viewpoint, the case illustrated provides an interesting historical perspective on a rare neurovascular disorder that continues to be debated in modern clinical research.

Dural arteriovenous fistulas in cerebral venous thrombosis: Data from the International Cerebral Venous Thrombosis Consortium

BACKGROUND AND PURPOSE

To explore the prevalence, risk factors, time correlation, characteristics and clinical outcome of dural arteriovenous fistulas (dAVFs) in a cerebral venous thrombosis (CVT) population.

METHODS

We included patients from the International CVT Consortium registries. Diagnosis of dAVF was confirmed centrally. We assessed the prevalence and risk factors for dAVF among consecutive CVT patients and investigated its impact on clinical outcome using logistic regression analysis. We defined poor outcome as modified Rankin Scale score 3-6 at last follow-up.

RESULTS

dAVF was confirmed in 29/1218 (2.4%) consecutive CVT patients. The median (interquartile range [IQR]) follow-up time was 8 (5-23) months. Patients with dAVF were older (median [IQR] 53 [44-61] vs. 41 [29-53] years; p < 0.001), more frequently male (69% vs. 33%; p < 0.001), more often had chronic clinical CVT onset (>30 days: 39% vs. 7%; p < 0.001) and sigmoid sinus thrombosis (86% vs. 51%; p < 0.001), and less frequently had parenchymal lesions (31% vs. 55%; p = 0.013) at baseline imaging. Clinical outcome at last follow-up did not differ between patients with and without dAVF. Additionally, five patients were confirmed with dAVF from non-consecutive CVT cohorts. Among all patients with CVT and dAVF, 17/34 (50%) had multiple fistulas and 23/34 (68%) had cortical venous drainage. Of 34 patients with dAVF with 36 separate CVT events, 3/36 fistulas (8%) were diagnosed prior to, 20/36 (56%) simultaneously and 13/36 after (36%, median 115 [IQR 38-337] days) diagnosis of CVT.

CONCLUSIONS

Dural arteriovenous fistulas occur in at least 2% of CVT patients and are associated with chronic CVT onset, older age and male sex. Most CVT-related dAVFs are detected simultaneously or subsequently to diagnosis of CVT.

Observation Versus Intervention for Low-Grade Intracranial Dural Arteriovenous Fistulas

BACKGROUND

Low-grade intracranial dural arteriovenous fistulas (dAVF) have a benign natural history in the majority of cases. The benefit from treatment of these lesions is controversial.

OBJECTIVE

To compare the outcomes of observation versus intervention for low-grade dAVFs.

METHODS

We retrospectively reviewed dAVF patients from institutions participating in the CONsortium for Dural arteriovenous fistula Outcomes Research (CONDOR). Patients with low-grade (Borden type I) dAVFs were included and categorized into intervention or observation cohorts. The intervention and observation cohorts were matched in a 1:1 ratio using propensity scores. Primary outcome was modified Rankin Scale (mRS) at final follow-up. Secondary outcomes were excellent (mRS 0-1) and good (mRS 0-2) outcomes, symptomatic improvement, mortality, and obliteration at final follow-up.

RESULTS

The intervention and observation cohorts comprised 230 and 125 patients, respectively. We found no differences in primary or secondary outcomes between the 2 unmatched cohorts at last follow-up (mean duration 36 mo), except obliteration rate was higher in the intervention cohort (78.5% vs 24.1%, P < .001). The matched intervention and observation cohorts each comprised 78 patients. We also found no differences in primary or secondary outcomes between the matched cohorts except obliteration was also more likely in the matched intervention cohort (P < .001). Procedural complication rates in the unmatched and matched intervention cohorts were 15.4% and 19.2%, respectively.

CONCLUSION

Intervention for low-grade intracranial dAVFs achieves superior obliteration rates compared to conservative management, but it fails to improve neurological or functional outcomes. Our findings do not support the routine treatment of low-grade dAVFs.

Detection and Differentiation of Dural Arteriovenous Fistulas in the Transverse Sinus/Sigmoid Sinus and Cavernous Sinus Using Carotid Ultrasound: Importance of Evaluation of the Occipital Artery

OBJECTIVES

Dural arteriovenous fistula (DAVFs) in the transverse sinus (TS)/sigmoid sinus (SS) and cavernous sinus (CS) are observed frequently in the clinic. This study aimed to detect DAVFs with ultrasound and compare carotid ultrasound findings between these conditions.

METHODS

We retrospectively reviewed 26 patients with either a TS/SS DAVF or a CS DAVF who were admitted to our hospital for evaluation of DAVFs from 2014 to 2018. The shunt site decision was made by neuroendovascular experts, whereas carotid ultrasound examinations were performed by ultrasound specialists. The flow velocity of the ipsilateral external carotid artery was reviewed in all 26 patients, whereas that of the occipital artery (OA) was examined in 20 patients. Blood flow velocities were compared between the TS/SS DAVF and CS DAVF groups.

RESULTS

The study included 18 patients with a TS/SS DAVF (11 women and 7 men; mean age ± SD, 65.3 ± 18.6 years) and 8 patients with a CS DAVF (7 women and 1 man; mean age, 70.4 ± 9.3 years). Evaluations of feeder arteries on cerebral angiography showed that all patients had dural branches from the internal carotid and middle meningeal arteries as feeders of CS DAVFs, whereas the OA was the major feeder source of all TS/SS DAVF cases. The end-diastolic velocity (EDV) of the external carotid artery was significantly higher in patients with a TS/SS DAVF compared with those with a CS DAVF (P = .004). The EDV of the OA was significantly elevated in TS/SS DAVF cases compared with CS DAVF cases (P < .001).

CONCLUSIONS

Duplex ultrasound parameters are significantly different between patients with TS/SS and CS DAVFs. An increased EDV of the OA can predict the presence of a TS/SS DAVF.

CTCFL expression is associated with cerebral vascular abnormalities

CTCFL is expressed in testis, oocytes and embryonic stem cells, and is aberrantly expressed in malignant cells, and is classified as a cancer-testis gene. We have previously shown by using a tetracycline-inducible Ctcfl transgene that inappropriate expression of Ctcfl negatively impacts fetal development and causes early postnatal lethality in the mouse. The affected pups displayed severe vascular abnormalities and localized hemorrhages in the brain evocative of cerebral cavernous malformations (CCM) and arteriovenous malformations (AVM) in humans. Thus, we aim to analyze; a) the presence of CCM-related proteins CCM1/KRIT1, CCM2/malcavernin and CCM3/PDCD10 in Ctcfl transgenic animals and, b) whether there is CTCFL expression in human CCM and AVM tissues. Ctcfl transgenic animals exhibited increased CD31 expression in vascular areas of the dermis and periadnexal regions but no difference was observed for vWF and α-SMA expressions. CCM-related proteins CCM1/KRIT1, CCM2/malcavernin and CCM3/PDCD10 were aberrantly expressed in coronal sections of the head in transgenic animals. We also observed CTCFL expression in human CCMs and AVMs. The induced expression of CTCFL resulting in vascular brain malformations in mice combined with the presence of CTCFL in human vascular malformations provide new insights into the role of this gene in vascular development in humans.

Central nervous system vascular malformations: A clinical review

CNS vascular malformation is an umbrella term that encompasses a wide variety of pathologies, with a wide range of therapeutic and diagnostic importance. This range spans lesions with a risk of devastating neurological compromise to lesions with a slow, static or benign course. Advances in neurovascular imaging along with increased utilization of these advances, have resulted in more frequent identification of these lesions. In this article, we provide an overview on definitions and classifications of CNS vascular malformations and outline the etiologic, diagnostic, prognostic, and therapeutic features for each entity. This review covers intracranial and spinal cord vascular malformations and discusses syndromes associated with CNS vascular malformations.

Vascular Myelopathies

PURPOSE OF REVIEW

Neurologists should be able to identify clinical and neuroimaging features that distinguish vascular disorders from other causes of myelopathy.

RECENT FINDINGS

Although certain clinical features suggest a vascular etiology in acute and chronic myelopathy settings, accurate MRI interpretation within the clinical context is key. Recent studies have shown vascular myelopathies are frequently misdiagnosed as transverse myelitis, and recognition of this diagnostic pitfall is important. Many different vascular mechanisms can cause myelopathy; this article provides a comprehensive review that simplifies disease categories into arterial ischemia, venous congestion/ischemia, hematomyelia, and extraparenchymal hemorrhage.

SUMMARY

It is important to recognize and manage vascular disorders of the spinal cord as significant causes of acute, subacute, and progressive myelopathy.

Vascular Abnormalities and the Role of Vascular Endothelial Growth Factor in the Epileptic Brain

Epilepsy is a chronic neurological disorder generally defined to be caused by excessive neuronal activity. Thus, excessive neuronal activity is the main target of the currently used antiepileptic drugs (AEDs). However, as many as 30% of epileptic patients show drug resistance to currently available AEDs, which suggests that epilepsy should be attributed not only to neuronal cells but also to other brain cells, such as glial cells and vascular cells. Astrocytes, pericytes, and endothelial cells in particular comprise the blood–brain barrier (BBB), which tightly regulates the exchange of substances between the brain parenchyma and the circulating blood. It has been proposed that BBB dysfunction, especially barrier leakage, exacerbates epileptic progression, and conversely, that epileptic seizures induce barrier leakage. Furthermore, several studies have shown that BBB dysfunction is one of the main causes of drug resistance in epilepsy. To better understand the mechanisms that link BBB dysfunction and intractable epilepsy to gain insights for the future development of treatments, we review and discuss the relationships between epilepsy and brain vascular abnormalities, mainly by focusing on vascular malformation, BBB dysfunction, and excessive angiogenesis. Because these abnormalities have been reported to be caused by vascular endothelial growth factor (VEGF) in the ischemic brain, we discuss the possible role of VEGF in vascular abnormalities in the epileptic brain, in which the upregulation of VEGF levels has been reported. Both glial cells and endothelial cells express VEGF receptors (VEGFRs); thus, these cells are likely affected by increases in VEGF during seizures, which in turn could cause vascular abnormalities. In this review, we review the possible role of VEGF in epilepsy and discuss the mechanisms that link vascular abnormalities and intractable epilepsy.

Differences in bleeding patterns and outcome after intracerebral hemorrhage due to vascular malformations

BACKGROUND

Atypical intracerebral hemorrhage is a common form of primary manifestation of vascular malformations.

OBJECTIVE

The aim of the present study is to determine clues to the cause of bleeding according to hemorrhage pattern (lobar, basal ganglia, infratentorial).

METHODS

We retrospectively evaluated 343 consecutive neurosurgical patients with intracerebral hemorrhage (ICH), who were admitted to our neurosurgical department between 2006 and 2016. The study cohort includes only neurosurgical patients. Patients who underwent treatment by neurologists are not represented in this study. We assessed location of hemorrhage, hematoma volumes to rule out differences and predicitve variables for final outcome.

RESULTS

In 171 cases (49.9%) vascular malformations, such as arteriovenous malformations (AVMs), cavernomas, dural fistulas and aneurysms were the cause of bleeding. 172 (50.1%) patients suffered from an intracerebral hemorrhage due to amyloid angiopathy or long standing hypertension. In patients with infratentorial hemorrhage a malformation was more frequently detected as in patients with supratentorial hemorrhage (36% vs. 16%, OR 2.9 [1.8;4.9], p<0.001). Among the malformations AVMs were most common (81%). Hematoma expansion was smaller in vascular malformation than non-malformation caused bleeding (24.1 cm3 vs. 64.8 cm3, OR 0.5 [0.4;0.7], p < 0.001,). In 6 (2.1%) cases diagnosis remained unclear. Final outcome was more favorable in patients with vascular malformations (63% vs. 12%, OR 12.8 [4.5;36.2], p<0.001).

CONCLUSION

Localization and bleeding patterns are predictive factors for origin of the hemorrhage. These predictive factors should quickly lead to appropriate vascular diagnostic measures. However, due to the inclusion criteria the validity of the study is limited and multicentre studies with further testing in general ICH patients are required.

Treatment of Ethmoidal Dural Arteriovenous Fistulas: A Meta-analysis Comparing Endovascular versus Surgical Treatment

BACKGROUND

Dural arteriovenous fistulas (DAVFs) in the anterior cranial fossa constitute approximately 1%-1.5% of intracranial vascular malformations. Depending on the drainage patterns, the diagnosis of ethmoidal DAVFs should prompt treatment because of the high risk of bleeding. Available treatments strategies are surgical treatment and the endovascular approach.

OBJECTIVE

To compare the surgical treatment with the endovascular therapy in terms of complete obliteration and perioperative adverse events.

METHODS

This study was performed according to the PRISMA guidelines. Eligible studies were identified through a search of PubMed and Cochrane until February 2019. A random effects model meta-analysis of odds ratios (OR) was conducted and the I-square was used to assess heterogeneity. Good outcome was defined as no neurologic deterioration within 30 days after the procedure.

RESULTS

Five studies comprising 81 patients were included in the meta-analysis. Surgical disconnection was superior to endovascular therapy in terms of postprocedural complete obliteration rate (surgery group, 100% [n = 65/65]; endovascular therapy, 47% [n = 15/32]; OR, 32.19; 95% confidence interval, 5.46-189.72; I² = 9.9%) and 30-day good outcome (surgery group, 98% [n = 63/64]; endovascular therapy, 47% [n = 15/32]; OR, 21.90; 95% confidence interval, 1.94-247.27; I² = 53.6%). No significant differences in terms of 30-day stroke, transient ischemic attack; visual deficit, new-onset seizure, and intracranial hemorrhage were identified.

CONCLUSIONS

Surgical treatment was superior to endovascular therapy in terms of complete obliteration and overall good outcome. Adverse event rates were similar between the 2 groups. Future studies should be conducted to validate our results.

Radiosurgical treatment of arteriovenous malformations in a retrospective study group of 33 children: the importance of radiobiological scores

PURPOSE

Arteriovenous malformations' (AVMs) obliteration depends on several factors; among the many factors that must be considered to obtain a high rate of obliteration and a low rate of complications, Flickinger-Pollock Score (FPS) seems to have an important role but still have to be validated in the pediatric population while Paddick-Conformity Index (PCI) still has no demonstration of its utility on the outcome and is considered only as a treatment quality marker.

METHODS

We retrospectively analyzed 33 consecutive children (2-18 years) with an AVM, treated with stereotactic radiosurgery Gamma Knife (SRS-GK) from 2001 to 2014 in our institution. We assess angiographic (DSA) Obliteration Rate (OR) as well FPS and PCI to draw conclusions.

RESULTS

DSA-OR was 60.6% with a rate of hemorrhage of 0%. median target volume (TV) was 3.60 cc (mean 4.32 ± 3.63; range 0.15-14.2), median PD was 22 Gy (mean 21.4 ± 2.6; range 16.5-25). Median percentage of coverage was 98% (mean 97 ± 3; range 84-100). The median modified FPS was 0.78 (mean 0.89 ± 0.52; range 0.21-2.1) and highly correlate with OR (p = 0.01). The median PCI was 0.65 (mean 0.65 ± 0.14; range 0.34-0.95) A PCI lower than 0.57 highly correlates with final OR (p = 0.02).

CONCLUSION

SRS-GK was safe and gradually effective in children. A prescription dose-like that used in adult population (i.e. > 18 and between 20 and 25 Gy) is essential to achieve obliteration. A PD of 23 Gy and 22 Gy did impact OR, respectively (p = 0.02) and (p = 0.05). FPS and PCI are valuable scores that seem to correlate with the OR also in the pediatric population although further prospective studies are needed to confirm these observations.

Epidemiology of ruptured brain arteriovenous malformation: a National Cohort Study in Korea

OBJECTIVE

Brain arteriovenous malformation (BAVM) is a rare cerebrovascular disease that causes intracranial hemorrhage. Although several reports have demonstrated the epidemiological features of BAVM in Western countries, no epidemiological investigations regarding BAVM have been reported in Korea. The authors aimed to investigate the national epidemiology of ruptured BAVM in a Korean population.

METHODS

The authors used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC). The original cohort included approximately 1 million individuals (2% of the Korean population) with 12-year claim data (2002-2013). To construct an initial cohort for investigation, the authors selected 1,016,820 registered individuals in 2005. Subjects with a history of cerebrovascular disease (code I6xx) and BAVM (Q282) between 2002 and 2004 were washed-out to identify incident cases. During the 9-year follow-up (2005-2013), the incidence of BAVM was calculated using the earliest date of diagnosis of ruptured or unruptured BAVM. Direct standardization was applied to the crude incidence. Mortality and disability were evaluated using registration data. Related diagnostic procedures were also analyzed.

RESULTS

A total of 8,802,696 person-years of observation were noted. During observation, 308 patients were diagnosed with a ruptured BAVM. The crude incidence of ruptured BAVM was 3.5 per 100,000 person-years. There was no sex difference in incidence. The mortality rate for patients with a ruptured BAVM 1 month after diagnosis was 12.7%. At 1-year and 5-year follow-up examinations, mortality rates were 17.2% and 22.1%, respectively. Severe disability-free survival rates of patients with ruptured AVMs were 75.3% and 69.8% at 1-year and 5-year follow-up, respectively.

CONCLUSIONS

The standardized incidence of ruptured BAVMs was 3.6 per 100,000 person-years in Korea. Ruptured BAVMs resulted in high mortality and disability rates.

Arterial spin labeling MR imaging aids to identify cortical venous drainage of dural arteriovenous fistulas

Cortical venous drainage (CVD) increases the probability of intracranial hemorrhage and mortality rate of dural arteriovenous fistulas (DAVF). Although digital subtraction angiography (DSA) is the most accurate method to determine CVD in DAVFs, this modality has limitations due to its invasive nature and radiation issues. The purpose of this study was to evaluate the diagnostic utility of arterial spin-labeling perfusion-weighted images (ASL-PWI) to identify CVD in patients with DAVF.The Institutional Review Board of our hospital approved this retrospective study. ASL-PWI features of 22 patients with DAVF were retrospectively reviewed for the presence of bright signal intensity in cortical veins and brain parenchyma. DAVF with bright signal intensity in cortical veins and/or brain parenchyma was regarded as having CVD. Using DSA as a reference standard, sensitivity, specificity, positive predictive value, and negative predictive value of ASL-PWI for detecting CVD were calculated.Based on DSA features, 11 (11/22, 50%) patients were classified as having "aggressive" pattern with CVD. Eleven (11/22, 50%) patients also showed bright signal intensity in cortical veins (9/22, 41%) and/or brain parenchyma (4/22, 18%) on ASL-PWI. The 11 patients who had "Aggressive" pattern on DSA were the same 11 patients who were classified as having "aggressive" pattern on ASL-PWI. ASL-PWI showed perfect diagnostic performance for identifying CVD with sensitivity, specificity, positive predictive value, and negative predictive value of 100% for all.Thus, ASL-PWI could be used as a noninvasive mean to predict the presence of CVD in patients with DAVFs. It has the potential as a screening tool to evaluate DAVF prior to invasive DSA.

Timing of surgery for ruptured supratentorial arteriovenous malformations

BACKGROUND

There are conflicting opinions regarding the optimal waiting time to perform surgery after rupture of supratentorial arteriovenous malformations (AVMs) to achieve the best possible outcome.

OBJECTIVE

To analyze factors influencing outcomes for ruptured supratentorial AVMs after surgery, paying particular attention to the timing of the surgery.

METHODS

We retrospectively investigated 59 patients admitted to our center between 2000 and 2014 for surgical treatment of ruptured supratentorial AVMs. We evaluated the effect of timing of surgery and other variables on the outcome at 2-4 months (early outcome), at 12 months (intermediate outcome) after surgery, and at final follow-up at the end of 2016 (late outcome).

RESULTS

Age over 40 years (OR 18.4; 95% CI 1.9-172.1; p = 0.011), high Hunt and Hess grade (4 or 5) before surgery (OR 13.5; 95% CI 2.1-89.2; p = 0.007), hydrocephalus on admission (OR 12.9; 95% CI 1.8-94.4; p = 0.011), and over 400 cm³ bleeding during surgery (OR 11.5; 95% CI 1.5-86.6; p = 0.017) were associated with an unfavorable early outcome. Age over 40 years (OR 62.8; 95% CI 2.6-1524.9; p = 0.011), associated aneurysms (OR 34.7; 95% CI 1.4-829.9; p = 0.029), high Hunt and Hess grade before surgery (OR 29.2; 95% CI 2.6-332.6; p = 0.007), and over 400 cm³ bleeding during surgery (OR 35.3; 95% CI 1.7-748.7; p = 0.022) were associated with an unfavorable intermediate outcome. Associated aneurysms (OR 8.2; 95% CI 1.2-55.7; p = 0.031), high Hunt and Hess grade before surgery (OR 5.7; 95% CI 1.3-24.3; p = 0.019), and over 400 cm³ bleeding during surgery (OR 5.8; 95% CI 1.2-27.3; p = 0.027) were associated with an unfavorable outcome at last follow-up. Elapsed time between rupture and surgery did not affect early or final outcome.

CONCLUSIONS

Early surgery in patients with ruptured supratentorial arteriovenous malformation is feasible strategy, with late results comparable to those achieved with delayed surgery. Many other factors than timing of surgery play significant roles in long-term outcomes for surgically treated ruptured supratentorial AVMs.

Radiosurgery for dural arteriovenous malformations

Intracranial dural arteriovenous malformations (DAVFs) are relatively uncommon vascular lesions characterized by the direct connection of dural arteries into dural venous sinuses or leptomeningeal veins. Strategies for the treatment of these complex lesions have evolved significantly over the past three decades, and include open surgical disconnection, endovascular embolization, stereotactic radiosurgery (SRS), or a combination of these approaches. Radiosurgical intervention is unique in offering significant benefits to patients while exposing them to few of the risks associated with more invasive interventions. In this chapter we provide an overview of DAVFs and discuss the features of these lesions that affect management. We focus, in particular, on radiosurgical management of these lesions, describing present treatment paradigms, the procedure for the treatment of DAVFs with SRS, and expected clinical outcomes using SRS.

Radiosurgical ablation of spinal cord arteriovenous malformations

Spinal cord arteriovenous malformations (SCAVMs) are rare entities that account for less than 20% of spinal masses. These lesions represent a unique clinical challenge, in that surgical or endovascular treatment is often associated with devastating functional consequences. Over the past few decades, radiosurgery has become a well-established treatment modality for SCAVMs, and may be a first-line treatment in many patients afflicted with this devastating disease. This chapter summarizes the data available regarding radiosurgical treatment of SCAVMs.

The natural history of cerebral arteriovenous malformations

Cerebral arteriovenous malformations (AVMs) are composed of a complex tangle of abnormal arteries and veins and are a significant source of cerebral hemorrhage and consequent morbidity and mortality in young adults, representing a diagnostic and therapeutic challenge. Current natural-history studies of cerebral AVMs report overall annual rates of 1% and 3% for the risk of epilepsy and hemorrhage, respectively. Unruptured AVMs have an annual hemorrhage rate of 2.2% while ruptured lesions have an annual hemorrhage rate of 4.5%. These hemorrhage rates are can change over time, particularly for hemorrhagic lesions, with the rebleed rate ranging from 6% to 15.8% in the first year after rupture across several studies. Besides hemorrhage, other significant risk factors for AVM hemorrhage include deep location, deep venous drainage, associated aneurysms, and pregnancy. Other factors include patient age, sex, and small AVM size, which are not currently considered significant risk factors for AVM hemorrhage. In addition to hemorrhage risk and seizure risk, the natural history of an AVM also encompasses the daily psychologic burden that a patient must endure knowing that he or she possesses an untreated AVM. This chapter reviews the epidemiology, clinical features, and natural history of cerebral AVMs.

Dural arteriovenous fistula-induced thalamic dementia: report of 4 cases

Nonhemorrhagic neurological deficits are underrecognized symptoms of intracranial dural arteriovenous fistulas (dAVFs) having cortical venous drainage. These symptoms are the consequence of cortical venous hypertension and portend a clinical course with increased risk of neurological morbidity and mortality. One rarely documented and easily misinterpreted type of nonhemorrhagic neurological deficit is progressive dementia, which can result from venous hypertension in the cortex or in bilateral thalami. The latter, which is due to dAVF drainage into the deep venous system, is the less common of these 2 dementia syndromes. Herein, the authors report 4 cases of dAVF with venous drainage into the vein of Galen causing bithalamic edema and rapidly progressive dementia. Two patients were treated successfully with endovascular embolization, and the other 2 patients were treated successfully with endovascular embolization followed by surgery. The radiographic abnormalities and presenting symptoms rapidly resolved after dAVF obliteration in all 4 cases. Detailed descriptions of these 4 cases are presented along with a critical review of 15 previously reported cases. In our analysis of these 19 published cases, the following were emphasized: 1) the clinical and radiographic differences between dAVF-induced thalamic versus cortical dementia syndromes; 2) the differential diagnosis and necessary radiographic workup for patients presenting with a rapidly progressive thalamic dementia syndrome; 3) the frequency at which delays in diagnosis occurred and potentially dangerous and avoidable diagnostic procedures were used; and 4) the rapidity and completeness of symptom resolution following dAVF treatment.

Endovascular therapy of low- and intermediate-grade intracranial lateral dural arteriovenous fistulas: a detailed analysis of primary success rates, complication rates, and long-term follow-up of different technical approaches

OBJECTIVE Sinus-preserving (SP) embolization techniques augment endovascular treatment options for intracranial lateral dural arteriovenous fistulas (DAVFs). The authors aimed to perform a retrospective comparison of their primary success rates, complication rates, and long-term follow-up with those of sinus-occluding (SO) treatment variants in the collective of low- and intermediate-grade lateral DAVFs (Cognard Types I-IIb). METHODS Clinical symptoms, complication rates, and Cognard grading prior to and after endovascular DAVF treatment using different technical approaches was retrospectively analyzed in 36 patients with lateral DAVF Cognard Types I-IIb. The long-term success rate was determined by a standardized questionnaire. RESULTS The SO approaches offered a higher rate of definitive fistula occlusion (93% SO vs 71% SP) but were accompanied by a significantly higher complication rate (33% or 20% SO vs 0% SP). The patients interviewed reported very high satisfaction with their health in long-term follow-up in both groups. CONCLUSIONS A higher rate of definitive fistula occlusion in the SO group was attained at the price of a significantly higher complication rate. The SP approaches offered a good primary success rate in combination with a very low complication rate. Despite some limitations of the data (e.g., a small sample size) the authors thus recommend an SP variant as the primary therapeutic option for the endovascular treatment of low- and intermediate-grade DAVFs. The SO approaches should be restricted to cases in which SP treatment does not achieve a downgrading to no worse than Cognard Type IIa.

Balloon protection of the Labbé vein during transarterial embolization of a dural arterio-venous fistula

INTRODUCTION

Endovascular treatment of type III dural arterio-venous fistulas can be challenging if the fistulous point is close to a functionally important cortical vein.

METHODS

A technique is described for temporary balloon protection of the vein of Labbé during transarterial Onyx embolization of a type III dural arterio-venous fistula. One illustrative case is presented. Careful anatomic consideration of the concerned venous segment (at the insertion point into the lateral sinus) and the choice of balloon minimized the risk of venous rupture.

RESULTS

Using this method, satisfactory progression of Onyx was obtained within the arterio-venous shunt while preserving the patency of the Labbé vein.

CONCLUSION

Temporary balloon protection of the Labbé vein is a feasible option to preserve its patency during embolization of dural arterio-venous fistulas. To the authors' knowledge, this is the first report on the use of temporary balloon protection of a cortical vein.

Outcome after intracranial haemorrhage from dural arteriovenous fistulae; a systematic review and case-series

Dural arteriovenous fistulae (DAVFs) are a rare cause of intracranial haemorrhage. We aimed to investigate outcome of patients with intracranial haemorrhage from a DAVF. We performed a systematic literature search for studies reporting outcome after intracranial haemorrhage caused by a DAVF. We used predefined selection criteria and assessed the quality of the studies. In addition, we studied outcome in all patients with DAVF who had presented with intracranial haemorrhage at two university centers in the Netherlands, between January 2007 and April 2012. We calculated case fatality and proportions of patients with poor outcome (defined as modified Rankin Scale ≥ 3 or Glasgow Outcome Scale ≤ 3) during follow-up. We investigated mean age, sex, mid-year of study and percentage of patients with parenchymal haemorrhage as determinants of case fatality and poor outcome. The literature search yielded 16 studies, all but two retrospective and all hospital-based. Combined with our cohort of 29 patients the total number of patients with DAVF-related intracranial haemorrhage was 326 (58 % intracerebral haemorrhage). At a median follow-up of 12 months case fatality was 4.7 % (95 % CI 2.5–7.5; 17 cohorts) and the proportion of patients with poor outcome 8.3 % (95 % CI 3.1–15.7; nine cohorts). We found no effect of mean age, sex, mid-year of the cohorts and percentage of patients with parenchymal haemorrhage on either outcome. Hospital based case-series suggest a relatively low risk of death and poor outcome in patients with intracranial haemorrhage due to rupture of a DAVF. These risks may be underestimated because of bias.

Four-dimensional computed tomography angiography is valuable in intracranial dural arteriovenous fistula diagnosis and fistula evaluation

This study was to evaluate the value of four-dimensional computed tomography angiography (4D-CTA) in the diagnosis of intracranial dural arteriovenous fistula (DAVF). This study included 16 patients who were diagnosed to have intracranial DAVF by digital subtraction angiography (DSA). The 4D-CTA was performed by Aquilion ONE multi-detector CT scanner (Toshiba Medical Systems, Japan) equipped with 320 × 0.5 mm detector rows. Standard biplane fluoroscopy equipments (Infinix, Toshiba Medical Systems, Japan and ADVANTX LC/LP, GE Medical Systems, Milwaukee, WI, USA) were applied in the diagnosis of intra-arterial DSA. Examinations were performed to evaluate the findings of DSA and 4D-CTA in each patient. The examination results were read by two independent readers in a blind manner. All results were documented on standardized scoring sheets. In all 16 cases, the same diagnosis results of intracranial DAVF were obtained from DSA and 4D-CTA. The results of subtype (Borden and Cognard classification), venous reflux and fistula sites were also accurately exhibited in 4D-CTA. In addition, there was a little discrepancy in identifying smaller and specific arterial branches and in distinguishing fistula type (focal or diffuse) using 4D-CTA. Good-to-excellent agreements were made between 4D-CTA and DSA. Therefore, 4D-CTA could be a feasible tool for the characterization of intracranial DAVF, with respect to determining fistula site and venous drainage.

Overall outcomes following early interventions for intracranial arteriovenous malformations with hematomas

We evaluated the timing and predictors of surgical intervention for intracranial arteriovenous malformations (AVM) with hematoma. A ruptured intracranial AVM with hematoma is an emergency condition, and the optimal timing for surgical intervention is not well understood. In addition, the outcome predictors of surgical intervention have rarely been reported. We identified and analyzed 78 patients treated with microsurgical resection for pathologically proven AVM at Louisiana State University Health in Shreveport from February 1992 to December 2004. All 78 patients were diagnosed with ruptured AVM before surgery. The independent variables, including patient demographics, timing of surgery, location of the AVM and comorbidities were analyzed to assess outcome. The results of this series revealed that surgical intervention after 48hours resulted in poor outcomes for patients with hematoma, following a ruptured AVM. Several other prognostic factors, including younger age (11-40years), Spetzler-Martin Grade I and II, and AVM in a supratentorial location, had significant positive effects on outcomes. However, hypertension, smoking, and a prior embolization showed significant negative effects on outcomes after surgery. The multiple logistic regression analyses also revealed that the timing of surgical intervention had a significant effect on outcomes in patients with hematoma following ruptured AVM. Early intervention is the key to success in these patients.

Progressive versus Nonprogressive Intracranial Dural Arteriovenous Fistulas: Characteristics and Outcomes

BACKGROUND AND PURPOSE

A minority of intracranial dural arteriovenous fistulas progress with time. We sought to determine features that predict progression and define outcomes of patients with progressive dural arteriovenous fistulas.

MATERIALS AND METHODS

We performed a retrospective imaging and clinical record review of patients with intracranial dural arteriovenous fistula evaluated at our hospital.

RESULTS

Of 579 patients with intracranial dural arteriovenous fistulas, 545 had 1 fistula (mean age, 45 ± 23 years) and 34 (5.9%) had enlarging, de novo, multiple, or recurrent fistulas (mean age, 53 ± 20 years; P = .11). Among these 34 patients, 19 had progressive dural arteriovenous fistulas with de novo fistulas or fistula enlargement with time (mean age, 36 ± 25 years; progressive group) and 15 had multiple or recurrent but nonprogressive fistulas (mean age, 57 ± 13 years; P = .0059, nonprogressive group). Whereas all 6 children had fistula progression, only 13/28 adults (P = .020) progressed. Angioarchitectural correlates to chronically elevated intracranial venous pressures, including venous sinus dilation (41% versus 7%, P = .045) and pseudophlebitic cortical venous pattern (P = .048), were more common in patients with progressive disease than in those without progression. Patients with progressive disease received more treatments than those without progression (median, 5 versus 3; P = .0068), but as a group, they did not demonstrate worse clinical outcomes (median mRS, 1 and 1; P = .39). However, 3 young patients died from intracranial venous hypertension and intracranial hemorrhage related to progression of their fistulas despite extensive endovascular, surgical, and radiosurgical treatments.

CONCLUSIONS

Few patients with dural arteriovenous fistulas follow an aggressive, progressive clinical course despite treatment. Younger age at initial presentation and angioarchitectural correlates to venous hypertension may help identify these patients prospectively.

Flat Detector Computed Tomography-Based "Dual Vessel Fusion" Technique for Diagnosis and Surgical Planning in the Management of Dural Arteriovenous Fistula

OBJECTIVE

To explore the value of flat detector computed tomography-based vessel fusion technique for visualizing and evaluating anatomic structures and hemodynamic features of patients diagnosed with dural arteriovenous fistulas (DAVF).

METHODS

Eleven patients with DAVF were investigated. The 3-dimensional structure of the DAVF fistula point, feeding arteries, and draining veins were reconstructed from separately acquired rotational angiographic images and then displayed as a single image in a fused manner.

RESULTS

In the vessel fusion image, the tangled cluster of vessels of the DAVF could be clearly visualized from selected optimal viewing angles in the 3-dimensional space. Each component of the DAVF fistula point with its specific artery feedings and venous drainage could be identified accurately.

CONCLUSIONS

The vessel fusion technique gave detailed anatomic information that enabled better understanding of the DAVF structure, and facilitated an accurate interventional or surgical planning.

A systematic review and meta-analysis of surgeries performed for treating deep-seated cerebral cavernous malformations

OBJECTIVE

The clinical benefit of surgery for treatment of deep-seated cerebral cavernous malformations (CCMs) is still a matter of debate. Although the surgical removal of CCMs is widely accepted, the benefits of reducing the rate of haemorrhage must be balanced against the risk of peri-operative morbidity. Here, we provide a systematic review and meta-analysis of the clinical benefits of surgery for treating deeply localised CCMs.

METHODS

A comprehensive search of PubMed and Embase was conducted to identify relevant studies. The rate and a 95% confidence interval (CI) were used to measure the risk of haemorrhage and adverse outcomes.

RESULTS

A total of 34 cohort studies reporting surgeries on CCMs were included in our analysis. Overall, the average post-surgical haemorrhage rate was 1.0% (95% CI: 0.7-1.4%). Nine per cent (95% CI: 6.9-11.3%) of the patients developed adverse events at follow-up following the surgical resection of deep-seated CCMs. The percentage of transient neural defects following surgical resection was 34.6% (95% CI: 29.4-39.9%). The proportions of transient focal neurological defect before and after the year 2006 were 44.9% (95% CI: 34.1-55.8%) and 30.3% (95% CI: 25.1-35.9%), respectively.

CONCLUSIONS

Our meta-analysis demonstrates post-surgical haemorrhage rate and complications related to surgeries on deep-seated CCMs. The post-surgical haemorrhage rate was low with a relatively high rate of post-surgical complications.

Optimal management of hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT), also known by the eponym Osler-Weber-Rendu syndrome, is a group of related disorders inherited in an autosomal dominant fashion and characterized by the development of arteriovenous malformations (AVM) in the skin, mucous membranes, and/or internal organs such as brain, lungs, and liver. Its prevalence is currently estimated at one in 5,000 to 8,000. Most cases are due to mutations in the endoglin (HHT1) or ACVRLK1 (HHT2) genes. Telangiectasias in nasal and gastrointestinal mucosa generally present with recurrent/chronic bleeding and iron deficiency anemia. Larger AVMs occur in lungs (~40%-60% of affected individuals), liver (~40%-70%), brain (~10%), and spine (~1%). Due to the devastating and potentially fatal complications of some of these lesions (for example, strokes and brain abscesses with pulmonary AVMs), presymptomatic screening and treatment are of utmost importance. However, due to the rarity of this condition, many providers lack an appreciation for the whole gamut of its manifestations and complications, age-dependent penetrance, and marked intrafamilial variation. As a result, HHT remains frequently underdiagnosed and many families do not receive the appropriate screening and treatments. This article provides an overview of the clinical features of HHT, discusses the clinical and genetic diagnostic strategies, and presents an up-to-date review of literature and detailed considerations regarding screening for visceral AVMs, preventive modalities, and treatment options.

Klippel-trénaunay syndrome with intracranial arteriovenous malformation: a rare presentation

Klippel-Trénaunay syndrome (KTS) is a rare vascular congenital anomaly affecting less than 200,000 people in the United States. Vascular malformations associated with KTS tend to affect slow flow systems: venous, capillary, and lymphatic systems. The nature of the syndrome leads to a higher risk for the development of arteriovenous malformations. Our case presentation describes a patient with KTS and an associated rare presentation of intraventricular arteriovenous malformation (AVM).