Intracranial Dural Arteriovenous Fistulas Research Articles

High-Flow Vascular Malformations in Children.

Children can have a variety of intracranial vascular anomalies ranging from small and incidental with no clinical consequences to complex lesions that can cause substantial neurologic deficits, heart failure, or profoundly affect development. In contrast to high-flow lesions with direct arterial-to-venous shunts, low-flow lesions such as cavernous malformations are associated with a lower likelihood of substantial hemorrhage, and a more benign course. Management of vascular anomalies in children has to incorporate an understanding of how treatment strategies may affect the normal development of the central nervous system. In this review, we discuss the etiologies, epidemiology, natural history, and genetic risk factors of three high-flow vascular malformations seen in children: brain arteriovenous malformations, intracranial dural arteriovenous fistulas, and vein of Galen malformations.

Transvenous Onyx embolization for dural arteriovenous fistula with concomitant transvenous balloon protection of the venous sinus.

The purpose of this study was to evaluate the technical efficacy and safety of transvenous Onyx embolization for dural arteriovenous fistulas (DAVFs) with concomitant transvenous balloon protection of the venous sinus when transarterial route failed or was not feasible. Between September 2010 and December 2016, thirty-six patients presenting with intracranial DAVFs underwent transvenous balloon-assisted Onyx embolization. The technical efficacy, treatment-related complications, and angiographic and clinical outcomes were reviewed from our prospectively maintained DAVF database. According to the Cognard Classification, 11 patients presented with clinically symptomatic Cognard type I; 11 cases with Cognard type IIa; 10 cases with Cognard type IIb; and 4 cases with Cognard type IIa+b. Complete angiographic occlusion of the DAVFs at the latest follow-up (mean 18 months after transvenous embolization) was achieved in 28 patients (77.8%), near-complete angiographic occlusion with minimal residual fistula in 5 patients (13.9%) and significant flow reduction of the DAVF in 2 patients (5.6%) and residual fistula for further treatment in 1 (2.8%) patient. Total clinical cure or remission of the pretreatment symptoms was achieved in 31 patients (31/36, 86.1%; 26 and 5 cases respectively). Affected venous sinus was preserved in 28 patients, intentionally occluded in 7 patients and gradually occluded in 1 patient. There were no immediate or long-term persistent complications after treatment. Transvenous Onyx embolization of dural arteriovenous fistulas with combined transvenous balloon protection of the venous sinus is safe and effective in achieving high occlusion rate, low embolization-related complications and satisfactory clinical outcomes.

Abstract 125: Observation versus Treatment for Low-Grade Intracranial Dural Arteriovenous Fistulas: A Multicenter Matched Cohort Study

Background and Purpose: Given the benign natural history of intracranial low-grade dural arteriovenous fistulas (dAVFs), their routine treatment remains controversial. The aim of this study is to compare the outcomes of low-grade dAVF treatment to conservative management. Methods: We performed a retrospective review of dAVF patients derived from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with low-grade (Borden I) dAVFs were included and categorized into treatment and observation cohorts. Primary outcome was defined as modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were rates of excellent (mRS 0-1) and good (mRS 0-2) functional outcomes, symptomatic improvement, mortality, and obliteration at final follow-up. Results: The treatment and observation cohorts comprised 230 and 112 patients, respectively. At last follow up, no difference in primary or secondary outcomes was observed between the two cohorts, with the exception of obliteration, which was higher in the treatment cohort (79.3% vs. 28.2%, p<0.001; Table 1). The two cohorts were then matched in a 1:1 ratio, resulting in 64 patients in each matched cohort. No difference in primary or secondary outcomes was observed between the matched cohorts, with the exception of obliteration, which was higher in the matched treatment cohort (75.4% vs. 28.6%, p<0.001; Table 2). Subgroup analysis of symptomatic patients demonstrated higher obliteration rate in the treatment cohort, but no difference in primary or other secondary outcomes were found. Conclusions: Low-grade dAVF treatment was not associated with increased functional disability compared to conservative management. Although higher obliteration rates were achieved in the treatment cohort, rates of symptomatic improvement were similar between the two cohorts. This study did not provide evidence to support the routine treatment of low-grade dAVFs.

Dural arteriovenous fistulas and headache features: an observational study

BackgroundDural arteriovenous fistulas are intracranial vascular malformations, fed by dural arteries and draining venous sinuses or meningeal veins. Clinical course varies widely and ranges from benign with spontaneous remission to fatal, due to cerebral hemorrhage. In a 10-year single institution experience, clinical presentation of dural arteriovenous fistulas, and in particular headache and angiographic features, as well as long-term outcome were analyzed.MethodsData of 42 intracranial dural arteriovenous fistulas of 40 patients concerning demographic characteristics, medical history and risk factors, clinical presentation and headache features, location and neuroimaging findings, as well as treatment and outcome, were collected. Furthermore, we used the modified-Rankin Scale to assess the long-term outcome, by telephone contact with patients and/or their relatives.ResultsPatients aged between 25 and 89 years (mean age 55.8 ± 15.5). According to different clinical presentation and evolution, related to their unique drainage pattern into the cavernous sinus, we examined the carotid-cavernous fistulas separately from other dural arteriovenous fistulas. Interestingly, we found that the migraine-like headache was the major onset symptom of dural arteriovenous fistulas different from carotid-cavernous fistulas (p = 0.036). On the other hand, non-migraine-like headache was a typical characteristic of carotid-cavernous fistulas (p = 0.003). Moreover, ocular symptoms were more frequently observed in carotid-cavernous fistulas (92.9% p < 0.001). Seventy percent of patients did not report any impact on quality of life (mRS 0 or 1) at follow-up.ConclusionsThese findings suggest a link between the site of lesion and clinical features of the headache, a symptom that usually leads to hospitalization. In particular, ocular symptoms accompanying non-migraine-like headache should be promptly recognized and raise the suspicion of a carotid-cavernous fistula, while migraine-like headache may suggests other dural arteriovenous fistulas. This study provides new significant insights on headache and its characteristics as a presentation symptom in dural arteriovenous fistulas.

Incidence of hereditary thrombophilia in patients with cranial dural arteriovenous fistulae

Dural arteriovenous fistulas (DAVFs) can develop as consequence of prior venous sinus thrombosis. However, the prevalence of prothrombotic conditions in patients with intracranial DAVFs is unknown and there is no consensus on the indications to screen for procoagulable conditions in these patients. We performed a retrospective review of patients presenting to our institution for management of cranial DAVF. Patient and DAVF characteristics were noted, in particular the incidence of hereditary thrombophilia (HT) detected by laboratory evaluation. Respective comparisons of patients with and without HT were performed using comparative statistics. There were 165 patients presenting for management of 171 DAVFs. A large proportion of DAVF were located at a large dural sinus (42.7%), which included superior sagittal, transverse, and sigmoid sinuses. On multivariate logistic regression analysis cortical venous drainage was independently associated with hemorrhagic presentation (OR 8.23, 95% CI 1.78–38.08; p = 0.007). A HT was detected in 18 of 61 patients (29.5%) who underwent a thrombophilia work-up. Location at a large dural sinus was not more common in patients with a HT (55.0% vs 54.5%; p = 0.97). There was also no difference in the presence of cortical venous drainage (56.5% vs 38.6%; p = 0.22) or hemorrhage on presentation (15.9% vs 5.0%; p = 0.22) in patients with and without a HT. In HT were found to be highly prevalent in our cohort, though our results do not suggest their presence greatly influences DAVF pathophysiology. Screening for procoagulable states is indicated in selected patients with an intracranial DAVF.

Complication rate, cure rate, and long-term outcomes of microsurgery for intracranial dural arteriovenous fistulae: a multicenter series and systematic review.

Although microsurgery is an established treatment modality for intracranial dural arteriovenous fistula (dAVF), data regarding the perioperative complication rate, cure rate, and long-term outcomes remain scarce. The aims of this study were to describe our original experience with microsurgery, including the surgical complications and pitfalls, and conduct a systematic review of the relevant literature. A multicenter cohort of patients with dAVF treated by microsurgery was retrospectively assessed. In addition, the PubMed database was searched for published studies involving microsurgery for dAVF, and the complication rate, cure rate, and long-term outcomes were estimated. The total number of patients in our multicenter series and published articles was 553 (593 surgeries). The overall rates of transient complications, permanent complications, death, and incomplete treatment were 11.4, 4.0, 1.2, and 6.5%, respectively. A favorable outcome was achieved for 90.1% patients, even though almost half of the patients presented with intracranial hemorrhage. Of note, the incidence of recurrence was only one per 8241 patient-months of postoperative follow-up. Surgeries for anterior cranial fossa dAVF were associated with a lower complication rate, whereas those for tentorial dAVF were associated with higher complication and incomplete treatment rates. The complication and incomplete treatment rates were lower with simple disconnection of cortical venous drainage than with radical occlusion/resection of dural shunts. Our findings suggest that the cure rate, complication rates, and outcomes of microsurgery for dAVF are acceptable; thus, it could be a feasible second-line treatment option for dAVF. However, surgeons should be aware of the specific adverse events of microsurgery.

Gamma Knife Radiosurgery: The Gold Standard Treatment for Intracranial Dural Arteriovenous Fistulas without Cortical Venous Drainage.

Endovascular therapy is currently the most common treatment approach for intracranial dural arteriovenous fistula (DAVF), followed by microsurgery. Gamma Knife radiosurgery (GKS) is usually reserved as the last modality of treatment of intracranial DAVF. To evaluate the clinical and radiological outcome of GKS in the treatment of DAVF without CVD. This series includes patients who underwent GKS for intracranial DAVF without CVD over 10 years (Jan 2007 to Dec 2016) in All India Institute of Medical Sciences, New Delhi. Their demographic profile, clinical presentation, imaging details, GKS details, and follow-up clinical status were obtained retrospectively. Clinical follow-up, along with radiological assessment using MRI every 6 months was done after GKS. DSA was performed once MRI strongly suggested obliteration of DAVF. Patients who had a clinical follow-up of less than 1 year were excluded from the study. 5 patients (4 males and 1 female) who had DAVF without CVD were included the study. The mean age was 44.8 years. All patients had complete obliteration of fistula on digital subtraction angiography (DSA) at a mean duration of 24 months post GKS. All patients had complete resolution of symptoms at the last follow-up. Gamma Knife surgery is the most effective and the safest treatment modality for dealing with DAVFs without CVD. Instead of reserving it as the last resort for patients with DAVF without CVD, it should be considered as the gold standard treatment for DAVFs without CVD.

Role of Surgery in the Management of Intracranial Dural Arteriovenous Fistula

Role of Surgery in the Management of Intracranial Dural Arteriovenous Fistula

Clinical Characteristics and Microsurgery Treatment of Anterior Cranial Fossa Dural Arteriovenous Fistula.

Anterior cranial fossa dural arteriovenous fistulas (DAVFs) represent 6% of all intracranial DAVFs and have a high risk of intracranial hemorrhage. To analyze the clinical characteristics and microsurgery treatment of anterior cranial fossa DAVFs, a retrospective review of 21 patients with anterior cranial fossa DAVFs undergoing microsurgery was performed, including 8 bleeding patients and 13 non-bleeding patients. The Glasgow coma scale (GCS) scores were used to evaluate the conscious states of 8 bleeding patients before and after operation. All patients had no obvious complications and the clinical symptoms were improved after operation. No abnormal fistulas and drainage veins were detected by digital subtraction angiography postoperatively. The GCS scores of 8 bleeding patients showed that the conscious states became better than pre-operation. Of the 21 patients, 9 patients were followed up without recurrence. Taken together, microsurgery is an effective method for the treatment of anterior cranial fossa DAVFs and it is very important for the improvement of bleeding patients' conscious states.

Reply to ‘The complex tale of Mantiqueira and Juiz de Fora: A comment on “Eoarchean to Neoproterozoic crustal evolution of the Mantiqueira and the Juiz de Fora Complexes, SE Brazil: Petrology, geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes”’ by K. Cutts and C. Lana

The radiological signs of intracranial dural arteriovenous fistulas (ICDAVFs) are heterogenous. While it is commonly accepted that hyper intense T2 wedge magnetic resonance imaging of the brainstem and cervical cord mainly concern gliomas, it is so far uncommon and probably unknown that ICDAVFs can imitate similar radiological pattern, especially with gadolinium contrast enhancement and cord enlargement. Thus the angiography is poorly documented in the diagnostic workup. We report the unusual history of ICDAVFs, revealed by clinical and radiological features that mimicked a medulla or cervical spinal cord glioma. This observation provides information on the management of atypical lesions mimicking medulla or cervical cord glioma and arguments for a careful radiological study. Looking for dilated veins around the brainstem and the cord is mandatory in the workup of a supposed infiltrating brainstem or spinal cord lesion, in order to rule out an ICDAVF. Even if the hyperintense T2 images associated with contrast enhancement is in favor of a brainstem or spinal cord glioma, additional cerebral angiography should be mandatory. Moreover, this clinical case highlights the need for a multidisciplinary approach including neuroradiologist, oncologist and neurosurgeon.

Subdural contrast effusion during endovascular therapy: case report

Accumulation of contrast medium in the subdural space after diagnostic intraarterial contrast administration is a rare observation. The authors report the case of a subdural contrast effusion (SCE) presenting during endovascular treatment of an intracranial dural arteriovenous fistula (DAVF) mimicking an acute subdural hematoma. Differentiation between the two by computed tomography (CT) or intraprocedural Dyna CT and early neurological examination can be crucial for patient management. We believe that repeated large-volume contrast injections via large-bore intermediate catheters into the territory of an (even partly) occluded DAVF may induce leakage of contrast medium into the extravascular subdural space thereby causing a SCE.

Diagnosis and Treatment of Intracranial Dural Arteriovenous Fistulas in View of Pathophysiology

Diagnosis and Treatment of Intracranial Dural Arteriovenous Fistulas in View of Pathophysiology

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas Involving the Transverse-Sigmoid Sinus : A Single Center Experience and Review of the Literatures.

ObjectiveWe retrospectively assessed the efficacy of stereotactic radiosurgery (SRS) for dural arteriovenous fistulas (DAVFs) involving the transverse-sigmoid sinus and analyzed the angiographic and clinical results with our 8-year experience. MethodsNine patients with intracranial DAVFs involving the transverse-sigmoid sinus underwent SRS using a Gamma Knife® (Elekta Inc., Atlanta, GA, USA) between 2009 and 2016. Five patients underwent SRS for residual DAVFs after embolization and four patients were treated with SRS alone. The median target volume was 1.9 cm3 (range, 0.8–14.2) and the median radiation dose of the target was 17 Gy (range, 16–20). The median follow-up period was 37 months (range, 7–81). ResultsPulsating tinnitus (33%) was the most common symptom. DAVFs were completely obliterated in four patients (44%) and subtotally obliterated in five (56%). Six patients (67%) showed complete recovery of symptoms or signs, and three (33%) showed incomplete recovery. One patient experienced a recurrent seizure. Adverse radiation effects after SRS occurred in one patient (11%). The total obliteration rates after SRS were 16.7%, 37.5%, and 68.7% at 1, 2, and 3 years, respectively. The median interval from SRS to total obliteration of the fistula was 31 months (range, 12–38). The rates at which the symptoms started to improve were 40% at 1 month and 80% at 2 months after SRS. Symptoms started to improve at a median of 5 weeks after SRS (range, 3–21). ConclusionSRS with or without embolization is a safe and effective treatment to relieve symptoms and obliterate DAVFs on the transverse-sigmoid sinus.

Are type I dural arteriovenous fistulas safe? Single-centre experience of endovascular treatment of dural arteriovenous fistulas.

IntroductionThere are mixed reports on the incidence of intracranial haemorrhage in patients with dural arteriovenous fistulas. We assessed new proposed risk factors (i.a. number of outflows and outflow diameter) of intracerebral haemorrhage due to intracranial dural arteriovenous fistula and presented our personal experience in endovascular treatment of dural arteriovenous fistulas.Material and methodsThe patient database from January 2006 and December 2016 was reviewed, and 25 patients with 28 dural arteriovenous fistulas were identified.Results50% of patients presented with intracerebral haemorrhage. Multiple dural fistulas occurred in 12% of patients. Spearman’s rank correlation coefficient revealed that there was a strong association between Cognard classification type and time needed to treat (r = 0.59, p < 0.05), as well as the volume of contrast used (r = 0.77, p < 0.05). Infratentorial (r = 0.53, p < 0.05) and right-sided (r = 0.66, p < 0.05) localisation were more challenging to treat. Bleeding was associated with poorer clinical outcome (r = 0.48, p < 0.05). No significant differences were found between the non-haemorrhagic group and the haemorrhagic group regarding the number of outflows (p = 0.459) and largest outflow diameter (p = 0.298). Clinical evaluation at follow-up was as follows: 56% of patients were asymptomatic, 24% had non-significant disability, maintaining independency, 16% had moderate disability, and 8% died – one in the course of intracerebral haemorrhage and one due to other sustained injuries. There were no reported embolisation-related complications.ConclusionsTo conclude, regardless of presentation, both symptomatic and asymptomatic dural arteriovenous fistulas deserve clinical attention, structured evaluation, and follow-up. Type I fistulas were associated with haemorrhage in 1/3 of all cases. Overall our results indicate that the risk of haemorrhage and dire consequences is multifactorial.

Introduction: microsurgical and endovascular management of intracranial dural arteriovenous fistula

Over the past decade substantial advances in diagnostic imaging, classification, and understanding the natural history of intracranial dural arteriovenous fistula (dAVF) have been made. Paralleling these improvements in patient evaluation and risk assessment have been considerable innovations and refinements in the microsurgical and endovascular techniques by which appropriately selected patients with dAVF are treated. On the microsurgical front, minimally invasive surgical approaches with less soft tissue and bony disruption, along with enhanced tools for the intraoperative assessment of vascular anatomy and completeness of dAVF obliteration, are now commonly utilized. On the endovascular front, liquid embolic agents, balloons, and flow-directed catheters have transformed our capacity to safely and effectively treat dAVFs with a variety of anatomic configurations and locations. Innovative combinations of microsurgical and endovascular approaches are even being applied to select cases. In this issue of Neurosurgical Focus, we present a series of narrated videos that demonstrate the decision-making, vascular anatomy, and technical nuances of many of these advanced techniques, while also providing narrated videos demonstrating tried-and-true microsurgical and endovascular approaches that have proven highly effective over the years. We hope this video supplement provides a meaningful update and demonstration of modern microsurgical and endovascular approaches to patients with dAVF and aids all of us in our unending quest to provide even better care for our patients in the future. We thank the authors for their outstanding contributions.

Treatment Outcomes According to Various Treatment Modalities for Intracranial Dural Arteriovenous Fistulas in the Onyx Era: A 10-Year Single-Center Experience

Although transarterial embolization (TAE) with Onyx has become popular for the treatment of dural arteriovenous fistulas (DAVFs), transvenous embolization (TVE), surgery, and radiosurgery have continued to have a role. The aim of the present study was to compare the treatment outcomes stratified by the different treatment modalities. The data from 92 patients with DAVFs treated from January 2009 to June 2018 were retrospectively reviewed. The treatment strategies were decided by a multidisciplinary team according to the patient's clinical status and angiographic findings. The clinical and radiologic data were analyzed and correlated with the treatment modality. A total of 101 procedures were performed in the 92 patients. TAE, TVE, surgery, and radiosurgery were performed in 31, 49, 12, and 9 procedures, respectively. Complete and near complete occlusion was achieved in 13 cases treated with TAE (41.9%), 41 treated with TVE (83.7%), and 10 with surgery (83.3%), as shown on immediate postprocedural angiography (P < 0.001). Retreatment was needed in 9 patients in the TAE group and none in the TVE or surgery groups (P < 0.001). Surgery (n= 1), TVE (n= 3), TAE (n= 1), and radiosurgery (n= 4) were used for patients requiring retreatment. At the last follow-up examination (mean, 26.5 ± 23.9 months), 66 of 72 DAVFs (91.6%) showed angiographic complete occlusion. Clinically, the initial symptoms had disappeared or improved in 87 of 90 patients (96.7%) at the last follow-up evaluation (mean, 26.4 ± 26.8 months). Even in the Onyx era, other treatment modalities still have important roles, as shown in the present study. Therefore, the selection of the appropriate treatment modality should be individualized by the angiographic findings and clinical symptoms.

Embryological Consideration of Dural AVFs in Relation to the Neural Crest and the Mesoderm.

Intracranial and spinal dural arteriovenous fistulas (DAVFs) are vascular pathologies of the dural membrane with arteriovenous shunts. They are abnormal communications between arteries and veins or dural venous sinuses that sit between the two sheets of the dura mater. The dura propria faces the surface of brain, and the osteal dura faces the bone. The location of the shunt points is not distributed homogeneously on the surface of the dural membrane, but there are certain areas susceptible to DAVFs. The dura mater of the olfactory groove, falx cerebri, inferior sagittal sinus, tentorium cerebelli, and falx cerebelli, and the dura mater at the level of the spinal cord are composed only of dura propria, and these areas are derived from neural crest cells. The dura mater of the cavernous sinus, transverse sinus, sigmoid sinus, and anterior condylar confluence surrounding the hypoglossal canal are composed of both dura propria and osteal dura; this group is derived from mesoderm. Although the cause of this heterogeneity has not yet been determined, there are some specific characteristics and tendencies in terms of the embryological features. The possible reasons for the segmental susceptibility to DAVFs are summarized based on the embryology of the dura mater.

Hybrid Capability to Integrate Multiple Treatment Modalities for Managing High-Grade Intracranial Dural Arteriovenous Fistulas

An integrated multimodality approach can be effective in treatment of high-grade dural arteriovenous fistulas. Nevertheless, this requires a high level of efficient cooperation between different departments, underlying a degree of bias in the decisional process. In comparison, hybrid capability, integrating these modalities in one hand, may allow aggregating multimodality treatment strategies by pooling their individual benefits, leading to a more holistic view of the consequences of each modality. We retrospectively reviewed 18 cases of dural arteriovenous fistulas subjected to a hybrid treatment approach at the Diakonieklinikum Jung-Stilling, Siegen, Germany, between March 2008 and January 2017. Nine cases were excluded. We selected 4 cases that highlight different aspects of hybrid capability for illustrative purposes. Hybrid capability allows treatment of a dural arteriovenous fistula based on the individual clinical situation of the patient and features of the lesion, free of interdepartmental bias. The surgeon maintains a level of flexibility that enables him or her to move from a minimally invasive endovascular approach to a maximally invasive surgical access according to the specific situation. Hybrid capability can lead to a highly efficient treatment regimen with palliation of symptoms and complete obliteration of the fistula, improving performance in these complex pathologies. Hybrid capability has great potential in the treatment of complex neurovascular lesions. It remains to be seen if a single surgeon with hybrid capability can supersede the current multidepartmental practice and achieve better outcomes.

Safety of Thrombolysis in a Patient with an Intracranial Dural Arteriovenous Fistula.

Intracranial dural arteriovenous fistulas are pathologic shunts between dural arteries and veins that have an inherent risk of intracranial hemorrhage.Systemic thrombolytic agents are a therapeutic option for high-risk pulmonary thromboembolism. Their potential benefits outweigh the risk of life-threatening bleeding; however, careful patient risk stratification should be performed and other options, such as surgical embolectomy or percutaneous catheter-directed treatment, should be considered if available.Multidisciplinarity is the key to better therapeutic decisions and the patient's opinion should always be taken into account.

Radiosurgery for Dural Arteriovenous Fistulas.

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous connections within the dura, in which meningeal arteries shunt blood directly into the dural sinus or leptomeningeal veins. Among all the treatment options for the treatment of DAVFs, stereotactic radiosurgery (SRS) is a safe and effective modality. SRS provides a minimally invasive therapy for patients who harbor less aggressive DAVFs without cortical vein drainage (CVD), but who suffer from intolerable headache, bruit, or ocular symptoms. For more aggressive DAVFs with CVD associated with immediate risks of hemorrhage, initial treatment with endovascular embolization or surgery for the prompt elimination of the aggressive components of DAVFs is necessary. In such cases, radiosurgery may serve as a secondary treatment for further management of residual nidus after initial intervention. The latent period for the effects of radiation to occur and the longer time for cure compared to surgery and endovascular therapy remains a major drawback for radiosurgery. However, the gradual obliteration of a DAVF after radiosurgery can avoid the immediate risk of aggravated venous hypertension or infarction, which sometimes complicates endovascular embolization and surgery.