Intracranial dural arteriovenous fistulas: clinical characteristics and management based on location and hemodynamics

Seizures associated with dural arteriovenous fistulas: A systematic review of cases

OBJECTIVE

Dural arteriovenous fistulas (DAVFs) are an unusual cause of seizures. In this systematic review, we aim to describe the clinical features, paraclinical findings, management, and prognosis of cases of DAVF-related seizures, raising awareness for a potentially treatable cause of epilepsy.

METHODS

This review was registered on PROSPERO (CRD42024529316). We searched OVID MEDLINE, OVID Embase, Web of Science, and Google Scholar for case reports/series of patients presenting with seizures associated with DAVFs. Original studies describing at least two out of four outcome categories (clinical features, paraclinical findings, treatment, and prognosis) were included. The methodological quality of each study was evaluated using a standardized tool. We performed descriptive analyses to summarize the clinical characteristics of all cases. We repeated these analyses while excluding cases where seizures may have had a likelier cause than DAVFs.

RESULTS

In total, 120 patients were included from 94 articles. Median age was 57 years, and most patients were male (70 %). The most common manifestations accompanying seizures were headaches (22 %). Status epilepticus occurred in 38 % of cases. DAVFs were most commonly in the left hemisphere. The main venous sinus involved was the transverse sinus. Cortical venous reflux was present in almost all cases (93 %); most DAVFs were considered aggressive according to Cognard and Borden classifications. Seizure freedom was most common following angiographic interventions.

CONCLUSION

DAVFs, even when uncomplicated, can be a potential cause of treatable seizures. More aggressive DAVFs with cortical venous reflux seem to be the main culprit. Angiographic interventions can help achieve seizure freedom.

Bridging the gap: A scoping review of endovascular and microsurgical approaches to anterior ethmoidal dural arteriovenous fistulas

INTRODUCTION

Dural arteriovenous fistulas (dAVF) are abnormal anastomoses between meningeal arteries and dural venous sinuses. Typically, dAVF treatment involves an endovascular or microsurgical approach. Anterior ethmoidal artery (AEA) dAVFs pose unique challenges due to their anatomy and location. We performed a scoping review to characterize pre and postoperative characteristics of AEA dAVFs and elucidate their optimal management.

METHODS

The authors conducted a comprehensive literature search on PubMed and Embase using Arskey & O'Malley's scoping review framework. The search strategy included "anterior," "ethmoidal," and "fistula" and excluded review articles and studies with unrelated pathology. Data collected included patient demographics, presentation, angiographic features, treatment modalities, and clinical and radiological outcomes.

RESULTS

One-hundred and two articles describing 273 patients with an average age of 58.79 years were included. Two-hundred and sixty patients had surgery; 127 (49 %) had endovascular embolization and 133 (51 %) had open surgery. Surgical approach was significantly associated with complete dAVF obliteration (p = 0.003, X2=8.73, N = 206); patients treated endovascularly were less likely to have complete dAVF obliteration (85.9 % for endovascular versus 97.2 % for microsurgery). Additionally, patients with preoperative dAVF rupture had significantly greater rates of postoperative hemorrhage (p = 0.003, X2=11.86, N = 184).

DISCUSSION

Surgical techniques and endovascular embolization are commonly used when treating dAVF, and our results highlight that open surgery appears to be superior to endovascular embolization when considering complete AEA dAVF obliteration. Despite advancements in treatment modalities, complications such as stroke, hemorrhage, and recurrence persist, emphasizing the importance of continued research and refinement of therapeutic strategies.

Dural arteriovenous fistula may be occluded through recanalization of impaired venous sinuses

To investigate the effect and safety of recanalization of stenosed or occluded venous sinuses for dural arteriovenous fistulas (DAVFs) and possible mechanism of DAVF formation, patients with DAVF accompanied by venous sinus stenosis or occlusion treated with balloon angioplasty and/or stenting were retrospectively enrolled. The clinical data, treatment outcomes and complications were analyzed. In 7 patients enrolled, the DAVF was Cognard IIa grade in 3 (42.9% or 3/7) and IIa + b in 4 (57.1% or 4/7) patients, including complex DAVFs in 2 (28.6% or 2/7). The angioplasty procedure was successful in all (100%) patients, including complete cure in 3 (42.9% or 3/7) patients with the initial Cognard grade IIa, transformation from Cognard grade IIa + b to I in 2 (28.6% or 2/7) patients, and unchanged Cognard grade IIa + b in 2 (28.6% or 2/7) patients. The symptoms were all improved. At 3-month angiographic follow-up, 5 (71.4% or 5/7) cases were cured, whereas 2 cases still had grade I fistulas but no clinical symptoms. Staged embolization in 2 patients resulted in significant symptom improvement. At the last follow-up of a median 4 years, no clinical symptoms were present in 5 (71.4% or 5/7) patients, intermittent headache in 1 (14.3% or 1/7), and death from trauma in 1 (14.3% or 1/7). In conclusion, endovascular recanalization of occluded or stenosed venous sinuses using balloon angioplasty and stenting is able to induce occlusion of DAVFs and is a safe and efficient treatment approach for DAVFs which are possibly caused by significant pressure increase.

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.

Prognosis of Rotational Angiography-Based Stereotactic Radiosurgery for Dural Arteriovenous Fistulas: A Retrospective Analysis

BACKGROUND

Cerebral dural arteriovenous fistulas (DAVFs) are intracranial vascular malformations with fine, abnormal vascular architecture. High-resolution vascular imaging is vital for their visualization. Currently, rotational angiography (RA) provides the finest 3-dimensional visualization of the arteriovenous shunt with high spatial resolution; however, the efficacies of the integration of RA have never been studied in stereotactic radiosurgery (SRS) for DAVFs until now. Since 2015, our institution has integrated RA into SRS (RA-SRS) to provide more conformal planning, thereby decreasing overtreatment and undertreatment.

OBJECTIVE

To analyze the outcomes of RA-SRS for DAVFs.

METHODS

We retrospectively analyzed the outcomes of 51 patients with DAVFs and compared those of 20 DAVFs treated with RA-SRS with those of 31 DAVFs treated with conventional SRS (c-SRS).

RESULTS

The time to obliteration was shorter in the RA-SRS group (median, 15 months vs 26 months [cumulative rate, 77% vs 33% at 2 years, 77% vs 64% at 4 years]; P = .015). Multivariate Cox proportional hazards analysis demonstrated that RA-SRS (hazard ratio 2.39, 95% CI 1.13-5.05; P = .022) and the absence of cortical venous reflux (hazard ratio 2.12, 95% CI 1.06-4.25; P = .034) were significantly associated with obliteration. The cumulative 5-year post-SRS stroke-free survival rates were 95% and 97% in the RA-SRS and c-SRS groups, respectively ( P = .615). Neurological improvement tended to occur earlier in the RA-SRS group than in the c-SRS group (median time to improvement, 5 months vs 20 months, log-rank test; P = .077).

CONCLUSION

RA-based SRS may facilitate earlier fistula obliteration and may contribute to early neurological improvement.

Case report: Transvenous coil embolization of a high-grade Galenic dural arteriovenous fistula

Introduction

Galenic dural arteriovenous fistulas (dAVFs) are a rare form of dAVF and rarely described in the literature. Their distinct location requires different surgical approaches than dAVFs occurring at the nearby sites of the straight sinus and torcular Herophili, and their high risk of hemorrhage makes these dAVFs very challenging to approach surgically. In this report, we present a unique case of Galenic dAVF.

Case description

The patient is a 54-year-old female who presented with a 2-year history of progressive headaches, cognitive decline, and papilledema. A cerebral angiogram demonstrated a complex dAVF to the vein of Galen (VoG). She underwent transarterial embolization with Onyx-18 which resulted in minimal reduction in arterial venous shunting. She subsequently underwent a successful transvenous coil embolization resulting in complete occlusion of dAVF. The patient's postoperative course was complicated by interventricular hemorrhage; however, she had a remarkable clinical recovery with resolution of headaches and improvement in cognitive function. A follow-up angiogram completed 6  months post-embolization demonstrated very mild residual shunting.

Conclusion

In the unique case presented here, we demonstrate the efficacy of transvenous embolization via an occluded straight sinus as an alternative therapeutic option to eliminate cortical venous reflux.

Update on Management of Dural Arteriovenous Fistulas

Abstract: Dural Arteriovenous Fistulas (AVF) represent about 10% of all intracranial vascular lesions. Although they seem benign in nature, the presence of retrograde venous makes them aggressive, with a high risk of complications. Patients may be clinically asymptomatic or experience symptoms ranging from mild to severe hemorrhage, depending on their location. Different treatments are available, but recently, the development of catheter intervention allows most patients to be cured with transcatheter embolization. Stereotactic radiosurgery achieves excellent rates of obliteration for low-grade lesions. In this review, we try to highlight the recent advances in the management of dural AVF.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas: A Systematic Review and Meta-Analysis and International Stereotactic Radiosurgery Society Practice Guidelines

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are often treated with stereotactic radiosurgery (SRS) to achieve complete obliteration (CO), prevent future hemorrhages, and ameliorate neurological symptoms.

OBJECTIVE

To summarize outcomes after SRS for dAVFs and propose relevant practice recommendations.

METHODS

Using a PICOS/PRISMA/MOOSE protocol, we included patients with dAVFs treated with SRS and data for at least one of the outcomes of the study. Relevant outcomes were CO, symptom improvement and cure, and post-SRS hemorrhage or permanent neurological deficits (PNDs). Estimated outcome effect sizes were determined using weighted random-effects meta-analyses using DerSimonian and Laird methods. To assess potential relationships between patient and lesion characteristics and clinical outcomes, mixed-effects weighted regression models were used.

RESULTS

Across 21 published studies, we identified 705 patients with 721 dAVFs treated with SRS. The CO rate was 68.6% (95% CI 60.7%-76.5%) with symptom improvement and cure rates of 97.2% (95% CI 93.2%-100%) and 78.8% (95% CI 69.3%-88.2%), respectively. Estimated incidences of post-SRS hemorrhage and PNDs were 1.1% (95% CI 0.6%-1.6%) and 1.3% (95% CI 0.8%-1.8%), respectively. Noncavernous sinus (NCS) dAVFs were associated with lower CO (P = .03) and symptom cure rates (P = .001). Higher grade was also associated with lower symptom cure rates (P = .04), whereas previous embolization was associated with higher symptom cure rates (P = .01).

CONCLUSION

SRS for dAVFs results in CO in the majority of patients with excellent symptom improvement rates with minimal toxicity. Patients with NCS and/or higher-grade dAVFs have poorer symptom cure rates. Combined therapy with embolization and SRS is recommended when feasible for clinically aggressive dAVFs or those refractory to embolization to maximize the likelihood of symptom cure.

Transarterial embolization for falx dural arteriovenous fistula through the artery of Davidoff and Schechter: A case report

Endovascular transarterial embolization is the standard treatment for the nonsinus-type of dural arteriovenous fistulae. Here, we report a rare case of successful transarterial embolization from the artery of Davidoff and Schechter for falx dural arteriovenous fistulae. A 74-year-old-man was incidentally diagnosed with falx dural arteriovenous fistulae during head magnetic resonance imaging. Results revealed dilatation of the cortical veins in the right occipital lobe. Angiographically, falx dural arteriovenous fistula was observed to be fed by the right middle meningeal artery, right occipital artery, right posterior meningeal artery, and the artery of Davidoff and Schechter (Borden type III). However, due to the tortuosity, the first transarterial embolization surgery through the middle meningeal artery, occipital artery, and posterior meningeal artery was unsuccessful. Therefore, the second transarterial embolization was performed through the artery of Davidoff and Schechter. Arteriovenous fistulae disappeared after administering Onyx injections through the artery of Davidoff and Schechter. Based on our findings, the artery of Davidoff and Schechter can be an approach route to treat dural arteriovenous fistulae. Moreover, the most important point of transarterial embolization procedures through the artery of Davidoff and Schechter is to navigate the microcatheter along the falx.

Transverse-sigmoid Sinus Dural Arteriovenous Fistula Presenting with False Localizing Signs of Cavernous Sinus Dural Arteriovenous Fistula Due to Obstructed Cerebral Venous Outflow into the Bilateral Superior Ophthalmic Veins: A Case Report

Cavernous sinus (CS) dural arteriovenous fistula (dAVF) presents ocular symptoms and visual disorders due to retrograde drainage from the CS into the superior ophthalmic vein (SOV). Some papers reported non-CS dAVFs with those symptoms. We present a unique case of transverse-sigmoid sinus (TSS) dAVF with localizing signs of CS dAVFs resulting from congested cerebral venous outflow into the CSs and SOVs in an 86-year-old female patient. Right pulsatile tinnitus and chemosis appeared a few years ago. After experiencing progressive bilateral blurred vision and decreased visual acuity with papillary edema for a few months, she was admitted to our hospital. Cerebral angiography demonstrated right sigmoid sinus dAVF with retrograde venous reflux into the superior sagittal sinus (SSS) and contralateral TSS without cortical venous reflux. Under the influence of congestion of the SSS, cerebral venous outflow drained into the CSs subsequently into the SOVs. Trans-arterial embolization using ethylene-vinyl alcohol copolymer was conducted via the right middle meningeal artery. After treatment, right chemosis immediately improved. The 2-month follow-up examination revealed resolution of bilateral visual acuity and improvement of papillary edema. Our case demonstrates that retrograde drainage into the SOVs with not only directly arterialized shunted flow but also congested cerebral venous outflow can cause CS dAVFs-like symptoms.

Endovascular versus surgical treatment of cranial dural arteriovenous fistulas: a single-center 8-year experience

BACKGROUND

Cranial dural arteriovenous fistulas (dAVFs) are rare lesions managed mainly with endovascular treatment (EVT) and/or surgery. We hypothesize that there may be subtypes of dAVFs responding better to a specific treatment modality in terms of successful obliteration and cessation of symptoms and/or risks.

METHODS

All dAVFs treated during 2011-2018 at our hospital were analyzed retrospectively. Presenting symptoms, radiological variables, treatment modality, complications, and residual symptoms were related to dAVF type using the original Djindjian classification.

RESULTS

We treated 112 dAVFs in 107 patients (71, 66% males). They presented with hemorrhage (n = 23; 21%), non-hemorrhagic symptoms (n = 75; 70%), or were discovered incidentally (n = 9; 8%). There were 25 (22%) type I, 29 (26%) type II, 26 (23%) type III, and 32 (29%) type IV fistulas. EVT was the primary treatment modality in 72/112 (64%) dAVFs whereas 40/112 (36%) underwent primary surgery with angiographic obliteration rates of 60% and 90%, respectively. Using a secondary treatment modality in 23 dAVFs, we obtained a final obliteration rate of 93%, including all type III/IV and 26/27 (96%) type II dAVFs. Except for headache, residual symptoms were rare and minor. Permanent neurological complications consisted of five cranial nerve deficits.

CONCLUSIONS

We recommend EVT as first treatment modality in types I, II, and in non-hemorrhagic type III/IV dAVFs. We recommend surgery as first treatment choice in acute hemorrhagic dAVFs and as secondary choice in type III/IV dAVFs not successfully occluded by EVT. Combining the two modalities provides obliteration in 9/10 dAVF cases at a low procedural risk.

Dural Arteriovenous Fistula-Derived Parkinsonism Symptoms: A Case Report with Literature Review

Objective

Parkinsonism caused by dural arteriovenous fistula (DAVF) is very rare, however, it is reversible by endovascular treatment. We herein report a case of parkinsonism caused by DAVF with review of previous literature.

Case Presentation

An 87-year-old woman with parkinsonism and dementia was admitted to our hospital with disturbance of consciousness and aggravated parkinsonism symptoms. Plain CT revealed low-density areas in the brainstem and left cerebellar peduncle. Magnetic resonance images revealed hyperintense lesions on FLAIR, which had elevated apparent diffusion coefficient (ADC) values, in the same lesion of plain CT. However, no edematous change was detected. CT angiograms revealed obstruction of the left transverse and sigmoid sinuses. Dilations of the left superior petrosal sinus, left petrosal vein, and pontine veins were also noted. A low-density area on plain CT had a contrast effect. Cerebral angiography revealed a DAVF involving the left transverse sinus and fed by the left occipital and left middle meningeal arteries. Transarterial embolization (TAE) with Onyx obliterated the DAVF, and parkinsonism symptoms gradually improved. We reviewed 21 DAVF-derived parkinsonism cases, most of which were treated by TAE. Recent cases were treated with Onyx. In many cases, parkinsonism improved after endovascular treatment.

Conclusion

DAVF-derived parkinsonism is rare but treatable by endovascular therapy. DAVF should be one of the differential diagnosis of the parkinsonisms.

Cerebral venous drainage in patients with dural arteriovenous fistulas: correlation with clinical presentation

OBJECTIVE

Dural arteriovenous fistulas (DAVFs) are abnormal, acquired arteriovenous connections within the dural leaflets. Their associated symptoms may be mild or severe and are related to the patient's venous anatomy. With the hypothesis that the patient's venous anatomy determines the development of symptoms, the authors aimed to identify which venous anatomy elements are important in the development of major symptoms in patients with a DAVF.

METHODS

A multicenter study was performed based on the retrospective analysis of cerebral angiographies with systematic assessment of brain drainage pathways (including fistula drainage) in patients over 18 years of age with a single DAVF. The patients were divided into two groups: those with minor (group 1, n = 112) and those with major (group 2, n = 89) symptoms. Group 2 was subdivided into two groups: patients with hemorrhage (group 2a, n = 47) and patients with severe nonhemorrhagic symptoms (group 2b, n = 42).

RESULTS

The prevalence of stenosis in DAVF venous drainage and the identification of tiny anastomoses between venous territories were significantly higher in group 2 (32.6% and 19.1%, respectively) compared with group 1 (2.68% and 5.36%, respectively). Stenosis of DAVF venous drainage was significantly more frequent in group 2a than in group 2b (51.1% vs 11.9%, p < 0.001). Group 2b patients had increased prevalence of shared use of the cerebral main drainage pathway (85.0% vs 53.2%, p = 0.002), the absence of an alternative route (45.0% vs 17.0%, p = 0.004), and the presence of contrast stagnation (62.5% vs 29.8%, p = 0.002) compared with group 2a patients. In patients with high-grade fistulas, the group with major symptoms had increased prevalence of a single draining direction (31.3% vs 8.33%, p = 0.003), stenosis in the draining vein (35.0% vs 6.25%, p = 0.000), the absence of an alternative pathway for brain drainage (31.3% vs 12.5%, p = 0.017), and the presence of contrast stagnation (48.8% vs 22.9%, p = 0.004).

CONCLUSIONS

Major symptoms were observed when normal brain tissue venous drainage was impaired by competition with DAVF (predominance in group 2b) or when DAVF venous drainage had anatomical characteristics that hindered drainage, with consequent venous hypertension on the venous side of the DAVF (predominance in group 2a). The same findings were observed when comparing two groups of patients with high-grade lesions: those with major versus those with minor symptoms.

Neurovascular trauma: Diagnosis and therapy

Traumatic cerebrovascular injuries are common in both military and civilian populations. Whether such injuries occur in the aftermath of blunt or penetrating trauma has major implications for characteristics, classification, diagnosis, and optimal management of these lesions. Advances in screening methods, including particularly the dramatic rise of high-quality CT angiography, have facilitated early detection of these lesions. Fortunately, these diagnostic advances have occurred alongside improvements in pharmacological treatment and endovascular intervention, which now play an important role alongside surgical intervention in reducing the likelihood of adverse clinical outcomes. While the management of victims of trauma remains challenging, improved understanding of and ability to appropriately manage traumatic cerebrovascular lesions promises to yield better clinical outcomes for these vulnerable patients.

Stereotactic Radiosurgery for Cavernous Sinus Versus Noncavernous Sinus Dural Arteriovenous Fistulas: Outcomes and Outcome Predictors

BACKGROUND

Dural arteriovenous fistulas (DAVFs) can be categorized based on location.

OBJECTIVE

To compare stereotactic radiosurgery (SRS) outcomes between cavernous sinus (CS) and non-CS DAVFs and to identify respective outcome predictors.

METHODS

This is a retrospective study of DAVFs treated with SRS between 1988 and 2016 at 10 institutions. Patients' variables, DAVF characters, and SRS parameters were included for analyses. Favorable clinical outcome was defined as angiography-confirmed obliteration without radiological radiation-induced changes (RIC) or post-SRS hemorrhage. Other outcomes were DAVFs obliteration and adverse events (including RIC, symptomatic RIC, and post-SRS hemorrhage).

RESULTS

The overall study cohort comprised 131 patients, including 20 patients with CS DAVFs (15%) and 111 patients with non-CS DAVFs (85%). Rates of favorable clinical outcome were comparable between the 2 groups (45% vs 37%, P = .824). Obliteration rate after SRS was higher in the CS DAVFs group, even adjusted for baseline difference (OR = 4.189, P = .044). Predictors of favorable clinical outcome included higher maximum dose (P = .014) for CS DAVFs. Symptomatic improvement was associated with obliteration in non-CS DAVFs (P = .005), but symptoms improved regardless of whether obliteration was confirmed in CS DAVFs. Non-CS DAVFs patients with adverse events after SRS were more likely to be male (P = .020), multiple arterial feeding fistulas (P = .018), and lower maximum dose (P = .041).

CONCLUSION

After SRS, CS DAVFs are more likely to obliterate than non-CS ones. Because these 2 groups have different total predictors for clinical and radiologic outcomes after SRS, they should be considered as different entities.

Angio-architecture of complex cranial dural arteriovenous fistulas: A single centre retrospective review of treatment modalities and outcomes

INTRODUCTION

Cranial dural arteriovenous fistulas (DAVFs) are rare vascular lesions that often harbour complex angio-architectural features. This subtype of DAVF may require multiple, multimodality, or hybrid treatments. In this paper we aim to identify specific angio-architectural features that are present in complex cranial DAVFs and we report our series with respect to treatment modalities and outcomes.

METHODS

Twenty-five cranial Borden type II and III cranial DAVFs were treated at our Institution from 2013 to 2017. We classified nine (36%) as complex based on specific angio-architectural features. Treatment strategies were based on fistula location, angiographic features and patient's presenting condition. Phone interviews were used to confirm outcome at 6 and 12 months.

RESULTS

Four patients (45%) presented with acute hydrocephalus, and 3 (33%) with intracranial hemorrhage. Multiple and combined treatment sessions were needed for all complex DAVFs. Five patients required 2 endovascular procedures each. One patient had 2 surgeries. The first line of treatment was endovascular in 6 cases (67%) and surgery in 3 (33%). Two treatment-related (22%) complications occurred. Complete disconnection was achieved in 5 out of 9 patients (55%). Two patients with an incomplete disconnection refused further treatment and were well at last follow up, with a partially treated fistula and persistent CVR. The other 3 patients concluded treatment after the end of our data collection period. At 1 year, 7/9 patients had stable or improved clinical symptoms, and 8/9 patients had GOS of 4 or 5.

CONCLUSIONS

Complex cranial DAVF often require a multidisciplinary approach and multiple treatment sessions should be expected. Specific angio-architectural features that increase DAVF complexity include multiple arterial feeders, especially transosseous or pial, reflux into multiple cortical veins, sinus occlusion/entrapment, venous aneurysms, segmental stenosis, medial or deep location, and association with the deep venous system.

Thrombosis of the straight sinus and microbleedings due to deep seated arteriovenous fistula - Hemodynamic changes, cognitive impairment and improvement after microsurgery. A technical report

Dural arteriovenous fistulas (dAVF) are rare vascular malformations accounting for only 10-15% that may lead to life threatening deficits due to hemodynamic changes in blood supply and pressure conditions. We present a 64-year old patient who was admitted with disorientation and aphasia. Following images confirmed an infratentorial dural fistula draining into the straight sinus. Additional findings were progressive thrombosis of the straight sinus, microbleedings and bithalamic edema due changes in hemodynamic conditions and venous congestion. Microsurgery was performed. After treatment improvement in clinical condition was observed and the venous congestion was regressive. Hemodynamic changes due to infratentorial dAVFs may lead to bleedings in deep regions and worsening of clinical condition fastly. Treatment requires carefully planning and visualization of angioarchitecture. Symptoms and hemodynamic changes are reversible after treatment, which are essential for treatment decisions.

The Incidence of Cranial Arteriovenous Shunts in Patients With Pulsatile Tinnitus: A Prospective Observational Study

OBJECTIVES

Finding the underlying cause for pulsatile tinnitus can be challenging. We aimed to determine the incidence of arteriovenous shunts, i.e., arteriovenous malformations (AVMs) or dural arteriovenous fistulas (dAVFs), in patients referred for catheter angiography (digital subtraction angiography [DSA]). Furthermore, we assessed which clinical features were predictive for the presence of such a lesion.

STUDY DESIGN AND METHODS

Fifty-one patients with pulsatile tinnitus, who were referred to us for DSA to exclude an arteriovenous shunt, were enrolled, prospectively.

MAIN OUTCOME MEASURES

DSA determined the presence of a dAVF or AVM. Clinical characteristics were recorded systematically and all patients underwent a physical examination.

RESULTS

Fifty patients were included in the final analyses. While no AVMs were found, a dAVF was found in 12 cases (24%). Three of these demonstrated cortical venous reflux, thus requiring treatment due to the risk of hemorrhage. In three cases (6%), DSA demonstrated a non-arteriovenous-shunt abnormality, likely causing the tinnitus. The odds of having a dAVF were significantly raised by unilaterality, objective bruit, and the ability to influence the tinnitus with compression. Unilaterality even had a negative predictive value of 1 and, if used as selection criterion, would have raised dAVF prevalence from 24 to 32%.

CONCLUSION

In a tertiary care setting, the prevalence of dAVFs in patients with pulsatile tinnitus is not negligible. Thus, patients with unilateral pulsatile tinnitus should be offered dynamic vascular imaging to rule out a dAVF. Especially, since some of these patients are at risk of intracranial hemorrhage and treatment options exist.

[Neuro-ophthalmological symptoms of intracranial dural arteriovenous fistulas]

OBJECTIVE

The study objective was to identify the main neuro-ophthalmological symptoms of intracranial dural arteriovenous fistulas (dAVFs) with different localization, based on clinical and angiographic correlations.

MATERIAL AND METHODS

We analyzed neuro-ophthalmological symptoms in 272 patients with dAVFs verified by direct angiographic examination. The localization of dAVFs was as follows: the cavernous sinus (CS) - 143 patients, the lateral sinuses (LSs) and the confluence of sinuses - 77 patients, and other locations - 52 patients.

RESULTS

Neuro-ophthalmological symptoms were detected in 163 (60%) patients. The symptoms were most typical of fistulas located in the CS (99% of patients with CS dAVFs). Neuro-ophthalmological symptoms were less typical of fistulas located in the LS and confluence (21% of patients with LS dAVFs) and dAVFs located outside of the CS and LS (9.6% of patients). Two main neuro-ophthalmological syndromes of intracranial dAVFs were identified: syndrome of obstructed venous outflow from the orbit and syndrome of intracranial hypertension (ICH). A correlation between neuro-ophthalmological symptoms and changes in the cerebral venous hemodynamics was found.

CONCLUSION

The syndrome of obstructed venous outflow from the orbit is pathognomonic for CS dAVFs. In some cases, obstruction of venous outflow from the orbit was observed in patients with dAVFs of other localization, with involvement of the CS and orbital veins in drainage of the fistula. The ICH syndrome reflects the most significant obstruction of venous outflow from the cranial cavity, which is characteristic of LS dAVFs with retrograde outflow in the sinuses and cerebral veins.

Straight sinus dural arteriovenous fistula presenting with reversible parkinsonism: A case report and literature review

RATIONALE

A dural arteriovenous fistula (DAVF) refers to an abnormal direct connection between an intracranial artery and a dural venous sinus. A DAVF presenting with parkinsonism is rare, and is therefore easily misdiagnosed. Therefore, early consideration of DAVF in the differential diagnosis of reversible parkinsonism is necessary.

PATIENT CONCERNS

We present the case of a 51-year-old male with progressive parkinsonism.

DIAGNOSES

He was diagnosed as straight sinus occlusion. Imaging studies revealed a DAVF associated with cerebral hypoperfusion of the lenticular nuclei and frontal lobe white matter.

INTERVENTIONS

Endovascular embolization was performed through his left occipital artery.

OUTCOMES

Treatment resulted in marked clinical improvement that a major improvement of parkinsonism was observed concomitant with no evidence of early venous drainage of this patient.

LESSONS

DAVF should always be considered as a potential cause of progressive parkinsonism on account of its potential reversibility. Our case suggests a concomitant role of basal ganglia degeneration and frontal white matter hypoperfusion in the pathology of parkinsonism due to DAVF. However, the precise pathophysiology remains to be investigated.

Spontaneous Resolution of Venous Aneurysms After Transarterial Embolization of a Variant Superior Sagittal Sinus Dural Arteriovenous Fistula: Case Report and Literature Review

We present a rare case of dural arteriovenous fistula (DAVF) with subarachnoid hemorrhage and intraventricular hemorrhage due to its venous aneurysms. A 63-year-old woman was admitted for a sudden loss of consciousness. Computed tomography angiograph, magnetic resonance imaging angiography, and digital subtraction angiography revealed a superior sagittal sinus DAVF. The fistula was fed by the left middle meningeal artery and left internal carotid artery, and was drained by a right vein of Trolard, the superficial Sylvian vein, deep Sylvian vein, and basal vein to the vein of Galen. The drainage veins were enlarged obviously with 3 aneurysmal venous malformations. There was a stenosis segment on the right basal vein. All the anatomic factors of direct cortical vein drainage, normal deep vein drainage, long tortuous drainage vein, outflow restriction, and multiple venous aneurysms, were contributed to the aggressive presentation of our case. Transarterial complete embolization of the fistula with balloon protection was successfully performed. Nine months later, a follow-up magnetic resonance imaging showed a complete disappearance of the 2 venous aneurysms located in the deep Sylvian vein and basal vein, and an obvious decrease in size of the venous aneurysm of the superficial Sylvian vein. This is the first report of a DAVF with 3 ballooned venous aneurysms and a spontaneous anatomy resolution of the venous aneurysms after the embolization of the fistula. At the same time, the clinical and radiologic characteristics of variant superior sagittal sinus DAVFs were summarized by review of the literatures reported previously.

Treating intracranial dural arteriovenous fistulas with gamma knife radiosurgery: A single-center experience

OBJECTIVE

We evaluated the effectiveness and safety of gamma knife radiosurgery (GKRS) for the treatment of intracranial dural arteriovenous fistulas (dural AVFs) over the past 10 years.

MATERIALS AND METHODS

The records of 21 patients diagnosed with dural AVFs between 2004 and 2014 and treated with GKRS were reviewed retrospectively. Complete obliteration (CO) was defined as total symptom relief plus confirmation through magnetic resonance imaging or conventional angiography.

RESULTS

The median follow-up was 70.5 months (range 3-136 months). Five patients underwent embolization (2 after GKRS). One patient underwent GKRS twice. The CO rate was 47%, and partial to CO rate was 88%. The complete symptom resolution rate was 77%, and all patients achieved partial to complete symptom resolution. The CO rates for Borden Type I and Type II/III dural AVFs were 66.7% and 25% (P = 0.153), respectively, and complete symptom-free rates were 76.9% and 75.0% (P = 1.000%), respectively. The median duration between initial GKRS and complete symptom resolution was 14.3 months. The median treatment to image-free durations for Borden Type I and Type II/III dural AVFs were 25.9 and 60.4 months (P = 0.028), respectively, and treatment to symptom-free durations were 10.6 and 36.7 months (P = 0.103), respectively. One patient had a recurrent hemorrhage. Two patients experienced brain edema after stereotactic radiosurgery and one patient experienced cystic formation after GKRS. The morbidity rate was 19% (four patients) and there was no mortality.

CONCLUSION

Treatment with GKRS for dural AVFs offers a favorable rate of obliteration. Patients with dural AVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using GKRS.

Intracranial and Spinal Dural Arterio-Venous Fistula (DAVF): A Surgical Series of 107 Patients

INTRODUCTION

Dural arteriovenous fistulas (DAVFs) is a challenging condition in vascular neurosurgery. Development of new endovascular techniques has progressively modified treatment strategies; however, surgery is still considered a valid option of treatment of this pathology.

MATERIALS AND METHODS

From a retrospective analysis of our database, we selected 107 patients who underwent surgical treatment for DAVFs. Patients were grouped into five categories according to the Borden and Cognard classifications. Patients and treatment characteristics/outcome is reported.

RESULTS

At admission, 30 (28 %) patients presented with intracranial hemorrhage. Fifteen (14 %) had seizure, whereas nearly half of the patients presented with non-aggressive symptoms, including headache (10, 9.3 %), cognitive impairment (8, 7.5 %), gait disturbance, and imbalance (8, 7.5 %). The majority of patients underwent surgical treatment of fistulas; in some cases, we elected combined surgical-endovascular (obliteration) treatment.

CONCLUSIONS

Management of DAVF requires a multidisciplinary assessment and treatment strategies including surgical, endovascular, and radiosurgical treatment. The data reported confirmed that surgical treatment of DAVFs is associated with a good clinical and radiological (complete occlusion of the fistula) outcome in all cases, with a low rate of complications.

Stereotactic radiosurgery for intracranial dural arteriovenous fistulas: a systematic review

OBJECT

The goal of this study was to evaluate the obliteration rate of intracranial dural arteriovenous fistulas (DAVFs) in patients treated with stereotactic radiosurgery (SRS), and to compare obliteration rates between cavernous sinus (CS) and noncavernous sinus (NCS) DAVFs, and between DAVFs with and without cortical venous drainage (CVD).

METHODS

A systematic literature review was performed using PubMed. The CS DAVFs and the NCS DAVFs were categorized using the Barrow and Borden classification systems, respectively. The DAVFs were also categorized by location and by the presence of CVD. Statistical analyses of pooled data were conducted to assess complete obliteration rates in CS and NCS DAVFs, and in DAVFs with and without CVD.

RESULTS

Nineteen studies were included, comprising 729 patients harboring 743 DAVFs treated with SRS. The mean obliteration rate was 63% (95% CI 52.4%–73.6%). Complete obliteration for CS and NCS DAVFs was achieved in 73% and 58% of patients, respectively. No significant difference in obliteration rates between CS and NCS DAVFs was found (OR 1.72, 95% CI 0.66–4.46; p = 0.27). Complete obliteration in DAVFs with and without CVD was observed in 56% and 75% of patients, respectively. A significantly higher obliteration rate was observed in DAVFs without CVD compared with DAVFs with CVD (OR 2.37, 95% CI 1.07–5.28; p = 0.03).

CONCLUSIONS

Treatment with SRS offers favorable rates of DAVF obliteration with low complication rates. Patients harboring DAVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using SRS.

Transcranial direct middle meningeal artery puncture for the onyx embolization of dural arteriovenous fistula involving the superior sagittal sinus

A 66-year-old woman presented with intermittent paraparesis and generalized tonic-clonic seizure. Cerebral angiography demonstrated dural arteriovenous fistula (AVF) involving superior sagittal sinus (SSS), which was associated with SSS occlusion on the posterior one third. The dural AVF was fed by bilateral middle meningeal arteries (MMAs), superficial temporal arteries (STAs) and occipital arteries with marked retrograde cortical venous reflux. Transfemoral arterial Onyx embolization was performed through right MMA and STA, but it was not successful, which resulted in partial obliteration of dural AVF because of tortuous MMA preventing the microcatheter from reaching the fistula closely enough. Second procedure was performed through left MMA accessed by direct MMA puncture following small decortications of cranium overlying the MMA using diamond drill one week later. Microcatheter could be located far distally to the fistula through 5 F sheath placed into the MMA and complete obliteration of dural AVF was achieved using 3.9 cc of Onyx.

Advances in Surgical Approaches to Dural Fistulas

Dural arteriovenous fistulas are abnormal connections of dural arteries to dural veins or venous sinuses originating from within the dural leaflets. They are usually located near or within the wall of a dural venous sinus that is frequently obstructed or stenosed. The dural fistula sac is contained within the dural leaflets, and drainage can be via a dural sinus or retrograde through cortical veins (leptomeningeal drainage). Dural arteriovenous fistulas can occur at any dural sinus but are found most frequently at the cavernous or transverse sinus. Leptomeningeal venous drainage can lead to venous hypertension and intracranial hemorrhage. The various treatment options include transarterial and transvenous embolization, stereotactic radiosurgery, and open surgery. Although many of the advances in dural arteriovenous fistula treatment have occurred in the endovascular arena, open microsurgical advances in the past decade have primarily been in the tools available to the surgeon. Improvements in microsurgical and skull base approaches have allowed surgeons to approach and obliterate fistulas with little or no retraction of the brain. Image-guided systems have also allowed better localization and more efficient approaches. A better understanding of the need to simply obliterate the venous drainage at the site of the fistula has eliminated the riskier resections of the past. Finally, the use of intraoperative angiography or indocyanine green videoangiography confirms the complete disconnection of fistula while the patient is still on the operating room table, preventing reoperation for residual fistulas.

Transverse and Sigmoid Sinus Dural Arteriovenous Fistula Mimicking Idiopathic Intracranial Hypertension and Carotid Cavernous Fistula

Intracranial dural arteriovenous fistulas (dAVFs) can produce a variety of symptoms depending on fistula location, size, and venous drainage. Although cavernous sinus fistulas (CCFs) classically present with symptoms of orbital venous congestion due to retrograde venous drainage into the superior ophthalmic vein (i.e. an arterialised "red eye") (Miller NR. Neurosurg Focus 2007;23:1--15), dAVFs not localised to the cavernous sinus rarely present with a "red eye" and instead produce increased intracranial pressure, which can mimic idiopathic intracranial hypertension (IIH). The authors present a unique case of an intracranial dAVF with clinical features suggestive of both CCF and IIH. Clinicians should be aware of this possibility to avoid delayed diagnosis of the intracranial dAVF.

Risk factors for dural arteriovenous fistula intracranial hemorrhage

To our knowledge, the risk factors for intracranial hemorrhage from dural arteriovenous fistula (DAVF) have not been systematically described, due to the complexity of their anatomy and low incidence. We performed this retrospective study to investigate the DAVF factors predicting intracranial hemorrhage. A 10year database of 144 consecutive patients with DAVF was reviewed. Data collected and analyzed were demographics, morphologic features of DAVF, sex, age, fistula flow rate, arterial supply, lesion location, and venous drainage pattern. Linear univariate and multivariate logistic regression analyses were used to evaluate the association between influencing factors and hemorrhage. A first linear univariate analysis was performed for all influencing factors, and showed that sex, lesion location, and venous drainage pattern were statistically significant in predicting intracranial hemorrhage (p<0.05). Secondary multivariate logistic regression analysis with sex, lesion location, and venous drainage pattern showed that only venous drainage pattern was statistically significant in predicting intracranial hemorrhage (p<0.05). Therefore, venous drainage pattern, particularly the cortical venous drainage, significantly predicts intracranial hemorrhage from DAVF. Both sex and lesion location may be confounding factors in predicting intracranial hemorrhage from DAVF, while the other factors may not be associated with hemorrhage.

Treatment of dural arteriovenous fistula by balloon-assisted transarterial embolization with Onyx

OBJECTIVE

This study evaluated the feasibility, safety, and efficacy of embolization of dural arteriovenous fistula via a very small, short feeding artery with the assistance of a balloon placed proximal to the tip of the microcatheter, such that the balloon serves as a plug.

METHODS

Eight patients who underwent treatment of DAVF by balloon-assisted transarterial embolization with Onyx were retrospectively reviewed. Gender, age, angiography findings, procedure details, clinical and angiographic outcomes, complications, and follow-up were recorded and analyzed.

RESULTS

Nine embolization procedures were performed in eight male patients via extracranial arteries. Balloon-assisted embolization was successful in all eight patients. A Hyperglide balloon was used in five patients, and a Hyperform balloon was used in three patients. Angiographic resolution of the fistula was achieved in all patients without complications. All patients recovered uneventfully. During the follow-up period of 7-19 months, all patients were asymptomatic except for one patient who experienced mild headaches.

CONCLUSIONS

Treatment of DAVF by balloon-assisted embolization with Onyx achieved promising results, even in patients with very small and short feeding arteries. This technique allowed the treatment of DAVF cases where other techniques have failed.