Cranial Dural Arteriovenous Fistulas Research Articles

Surgical treatment of anterior cranial fossa dural arterio-venous fistulas (DAVFs): a two-centre experience.

Anterior cranial fossa dural arterio-venous fistulas (DAVFs) represent 6% of all intracranial DAVFs; characteristically they show an aggressive behaviour with high risk of intracranial haemorrhage. Peculiar anatomical features, such as feeding by the ethmoidal arteries and the pattern of venous drainage (frequently with varices that mimic aneurysmal dilatation), can be evaluated in detail only by digital subtraction angiography (DSA), which represents the "gold standard" in the diagnosis of such cranial fistulas. Recent technological developments in endovascular management of this type of DAVF have partially reduced the morbidity risk related to this modality of treatment. Our purpose is to present our experience in the surgical management of 14 patients with anterior cranial fossa DAVFs, with attention paid to the possible role of preoperative embolisation in these cases and to the surgical technique. Between 1999 and 2015, 14 patients with anterior cranial fossa DAVFs were submitted to surgery in two neurosurgical departments; the mean age was 63years old; nine DAVFs caused intracranial haemorrhage (subarachnoid haemorrhage in three cases, intracerebral haemorrhage in six cases). Pre-operative embolisation was attempted in an early case and was successfully done in one recent case. In all patients, the surgical approach chosen was a pterional craniotomy with a low margin on the frontal bone in order to gain the exposure of the anterior cranial fossa and especially of the olphactory groove region; the resection of the falx at its insertion on the crista galli was needed in five cases in order to get access to the contralateral afferent vessels. Cauterisation of all the dural feeders on and around the lamina cribrosa was needed in all cases; venous dilatations were evident in eight patients (in seven out of nine patients with ruptured DAVF and in one out of five patients with unruptured DAVF) and were removed in all cases. One patient harboured an ophthalmic artery aneurysm, which was excluded by clipping. One patient died 5days after surgery due to the severity of the pre-operative haemorrhage. Postoperative DSA showed the disappearance of the DAVF and of the venous pseudo-aneurysms in all cases. Clinical outcome was favourable (without neurological deficits) in 11 patients; three patients presented an unfavourable clinical outcome, due to the severity of the initial haemorrhage. Surgical exclusion of the anterior cranial fossa DAVFs still represents the gold standard for such lesions, due to low post-operative morbidity and to complete protection against future rebleedings; endovascular techniques may help the surgeon in complex cases.

Embolization of Intracranial Dural Arteriovenous Fistulas Using PHIL Liquid Embolic Agent in 26 Patients: A Multicenter Study.

The introduction of liquid embolic agents has revolutionized endovascular approach to cranial vascular malformations. The aim of the study was to retrospectively assess the efficacy and safety of Precipitating Hydrophobic Injectable Liquid (PHIL), a new nonadhesive liquid embolic agent, in the treatment of patients with cranial dural arteriovenous fistulas. The primary end point was the rate of complete occlusion of dural arteriovenous fistulas. Secondary end points included the incidence of adverse events and clinical status at 3-month follow-up. This was a retrospective multicenter study. Twenty-six consecutive patients with dural arteriovenous fistulas (de novo or previously treated) treated by injection of PHIL only or with PHIL in combination with other embolization products (such as Onyx or detachable coils) were included in the study. Recruitment started in August 2014 and ended in September 2015. Twenty-two (85%) patients were treated with PHIL only, with 3 patients treated with both PHIL and Onyx, and 1, with both PHIL and coils. Immediate complete angiographic occlusion was achieved in 20 (77%) patients. Of the 6 patients with residual fistulas, 3 were retreated with PHIL and 1 achieved angiographic cure. An adverse event was seen in 1 patient who developed worsening of preexisting ataxia due to acute thrombosis of the draining vein. PHIL appears to be safe and effective for endovascular treatment of cranial dural arteriovenous fistulas. Short-term angiographic and clinical results are comparable with those of Onyx, with the added advantage of easier preparation and improved homogeneous cast visualization. The use of iodine as a radio-opacifier also produces considerably less artifacts on CT compared with tantalum-based embolic materials.

Usefulness of 3-Tesla magnetic resonance arterial spin-labeled imaging for diagnosis of cranial dural arteriovenous fistula

Background and purposeConventional digital subtraction angiography (DSA) has been a useful tool for the diagnosis of cranial dural arteriovenous fistula (cDAVF). In most patients with cDAVF, blood flow through the arteriovenous shunt was pooled at diseased veins and/or sinuses. Therefore, we speculated that pooled blood at diseased veins in patients with cDAVF could be detected on arterial spin-labeled imaging (ASL). The purpose of the present study was to investigate the usefulness of ASL to detect cDAVF. Materials and methodsConsecutive 13 patients with cDAVF who were admitted to our hospital between April 2013 and September 2016 were included in our study. We performed magnetic resonance imaging (MRI), including ASL, before DSA and within 7days after treatment for all of our patients. The accuracy for diagnosis of cDAVF was compared between conventional MRI findings and ASL findings. We also investigated the difference in ASL findings before and after treatment. ResultsWe could detect venous ASL signals in 12 patients, and this was more sensitive for diagnosis of cDAVF versus conventional MRI findings. ASL found the same location of cDAVF as conventional angiography. After successful treatment, venous ASL signals disappeared. ConclusionsASL might be useful to detect cDAVF and predict the location of diseased sinuses.

Evolution of treatment and a detailed analysis of occlusion, recurrence, and clinical outcomes in an endovascular library of 260 dural arteriovenous fistulas.

OBJECTIVE Many small series and technical reports chronicle the evolution of endovascular techniques for cranial dural arteriovenous fistulas (dAVFs) over the past 3 decades, but reports of large patient series are lacking. The authors provide a thorough analysis of clinical and angiographic outcomes across a large patient cohort. METHODS The authors reviewed their endovascular database from January 1996 to September 2015 to identify patients harboring cranial dAVFs who were treated initially with endovascular approaches. They extracted demographic, presentation, angiographic, detailed treatment, and long-term follow-up data, and they evaluated natural history, initial angiographic occlusion, complications, recurrence, and symptomatic resolution rates. RESULTS Across a cohort of 251 patients with 260 distinct dAVFs, the overall initial angiographic occlusion rate was 70%; recurrence or occult residual lesions were seen on subsequent angiography in 3% of cases. The overall complication rate was 8%, with permanent neurological complications occurring in 3% of cases. Among 102 patients with dAVFs without cortical venous reflux, rates of resolution/improvement of pulsatile tinnitus and ocular symptoms were 79% and 78%, respectively. Following the introduction of Onyx during the latter half of the study period, the number of treated dAVFs doubled; the initial angiographic occlusion rate increased significantly from 60% before the use of Onyx to 76% after (p = 0.01). In addition, during the latter period compared with the pre-Onyx period, the rate of dAVFs obliterated via a transarterial-only approach was significantly greater (43% vs 23%, p = 0.002), as was the number of dAVFs obliterated via a single arterial pedicle (29% vs 11%, p = 0.002). CONCLUSIONS Overall, in the Onyx era, the rate of initial angiographic occlusion was approximately 80%, as was the rate of meaningful clinical improvement in tinnitus and/or ocular symptoms after initial endovascular treatment of cranial dAVFs.

Ocular Signs Caused by Dural Arteriovenous Fistula without Involvement of the Cavernous Sinus: A Case Series with Review of the Literature.

Carotid cavernous fistula is a well-known clinical and angiographic entity responsible for ocular signs and symptoms. On the contrary, ocular signs are unusual in the presentation of cranial dural arteriovenous fistulas at locations other than the cavernous sinus. We retrospectively analyzed data focusing on the pathophysiology of ophthalmologic signs and their angiographic explanations. Thirteen patients were included with a mean age of 50 years. The most common signs were chemosis (61.5%), loss of visual acuity (38.5%), exophthalmia (38.5%), and ocular hypertension (7.7%). Dural arteriovenous fistulas presenting with ocular signs could be classified into 4 types due to their pathologic mechanism (local venous reflux into the superior ophthalmic vein, massive venous engorgement of the cerebrum responsible for intracranial hypertension, compression of an oculomotor nerve by a venous dilation, or intraorbital fistula with drainage into the superior ophthalmic vein).

Macrovascular Lesions Underlying Spontaneous Intracerebral Hemorrhage.

Spontaneous intracerebral hemorrhage (ICH) is a morbid disease with a high case fatality rate. Prognosis, rehemorrhage rates, and acute, clinical decision making are greatly affected by the underlying etiology of hemorrhage. This review focuses on the evaluation, diagnosis, and management of structural, macrovascular lesions presenting with ICH, including ruptured aneurysms, brain arteriovenous malformations, cranial dural arteriovenous fistulas, and cerebral cavernous malformations.

Complications of Sigmoid Sinus Transvenous Occlusion for the Endovascular Treatment of Dural Arteriovenous Shunts with Emphasis on Inner Ear Dysfunction

Embolization of cranial dural sinus arteriovenous fistulae with transvenous occlusion of the involved sinuses is an established strategy when the collateral brain drainage allows it. We aimed to investigate the frequency and types of complications after endovascular occlusion of the sigmoid sinus. From our database, we detected 52 endovascularly treated consecutive cases of cranial dural arteriovenous shunts involving the sigmoid sinus. The cases treated through the transvenous approach alone or combined with the transarterial one were analyzed retrospectively. Previously reported series and cases were reviewed and critically analyzed. In 15 cases, a transvenous approach was used and in 4 combined a transvenous approach with a transarterial approach. Two patients (13.3%) both treated with the transvenous approach alone presented postoperatively with vertigo and hearing loss. In the first case, the sinus occlusion involved the whole sigmoid sinus, whereas in the second case the occlusion was restricted to a parallel channel posteriorly to the proximal segment of the sigmoid sinus. Magnetic resonance imaging and ear, nose, and throat investigations failed to elucidate the cause and pathomechanism of these symptoms. No other complications occurred. Although the transvenous occlusion of the sigmoid sinus generally is a safe therapeutic option for the treatment of dural arteriovenous fistulae, inner ear dysfunction is still a possible complication. The combined analysis of the reported and our cases did not allow a plausible explanation of this complication and its pathomechanism remains obscure.

CT and MR imaging of non-cavernous cranial dural arteriovenous fistulas: Findings associated with cortical venous reflux

PurposeTo compare the conventional CT and MR findings of DAVFs in relation to the venous drainage pattern on digital subtraction angiography (DSA). Materials and MethodsCross-sectional imaging findings (CT and/or MR) in 92 patients were compared to the presence of cortical venous reflux (CVR) on DSA. ResultsImaging features significantly more prevalent in patients with CVR included: abnormally dilated and tortuous leptomeningeal vessels (92% vs. 4%, p<0.001) or medullary vessels (69% vs. 0%, p<0.001), venous ectasias (45% vs. 0%, p<0.001) and focal vasogenic edema (38% vs. 0%, p<0.001). The following findings trended towards association but did not reach the p value established following Bonferroni correction: dilated external carotid artery branches (71% vs. 38%, p=0.005), cluster of vessels surrounding dural venous sinus (50% vs. 19%, p=0.009), presence of hemorrhage (33 vs. 12%, p=0.040), and parenchymal enhancement (21% vs. 0%, p=0.030). ConclusionIn the appropriate clinical setting, recognition of ancillary signs presumably related to venous arterialization and congestion as well as arterial feeder hypertrophy should prompt DSA confirmation to identify DAVFs associated with CVR.

Four-dimensional computed tomography angiographic evaluation of cranial dural arteriovenous fistula before and after embolization

PurposeThis study aimed to evaluate the usefulness of four-dimensional CTA before and after embolization treatment with ONYX-18 in eleven patients with cranial dural arteriovenous fistulas, and to compare the results with those of the reference standard DSA. Patients and MethodsEleven patients with cranial dural arteriovenous fistulas detected on DSA underwent transarterial embolization with ONYX-18. Four-dimensional CTA was performed an average of 2 days before and 4 days after DSA. Four-dimensional CTA and DSA images were reviewed by two neuroradiologists for identification of feeding arteries and drainage veins and for determining treatment effects. Interobserver and intermodality agreement between four-dimensional CTA and DSA were assessed. ResultsForty-two feeding arteries were identified for 14 fistulas in the 11 patients. Of these, 36 (85.71%) were detected on four-dimensional CTA. After transarterial embolization, one patient got partly embolized, and the fistulas in the remaining 10 patients were completely occluded. The interobserver agreement for four-dimensional CTA and intermodality agreement between four-dimensional CTA and DSA were excellent (κ=1) for shunt location, identification of drainage veins, and fistula occlusion after treatment. ConclusionFour-dimensional CTA images are highly accurate when compared with DSA images both before and after transarterial embolization treatment. Four-dimensional CTA can be used for diagnosis as well as follow-up of cranial dural arteriovenous fistulas in clinical settings.

Endovascular Approach for Treatment of Frontal Dural Arteriovenous Fistula through the Ophthalmic Arteries using Glue: A Case Presentation with Review of Literature

A rare case of right frontal bleed in elderly gentleman secondary to anterior cranial fossa dural arteriovenous fistula was detected on computed tomography angiogram, and complete endovascular embolization was achieved through ophthalmic arteries using glue as embolic material. Successful endovascular treatment along with surgical evacuation of subdural hematoma resulted in excellent recovery of the patient. Quick in-and-out approach using flow directed microcatheters and fast embolizing potential of glue may allow for rapid, safe, and successful embolization of such fistulas. The rarity of the location and the transarterial glue embolization of the nidus by micro catheter through both ophthalmic arteries makes this an interesting case for discussion.

Cranial dural arteriovenous shunts. Part 3. Classification based on the leptomeningeal venous drainage.

The commonly used Borden and Cognard classification systems for the prediction of clinical behavior of cranial dural arteriovenous shunts focus on the venous drainage, particularly the presence of leptomeningeal venous drainage, and on the direction of flow, particularly the presence of retrograde flow. In addition, the latter includes ectasia and spinal drainage as criteria of two distinct grades. However, none of the above classifications (a) differentiates direct from exclusive leptomeningeal venous drainage, (b) considers cortical venous congestion as a factor potentially associated with an aggressive clinical course, and (c) anticipates ectasia in shunts with a mixed dural-cortical venous drainage (type 2). In this study, we analyzed the angiographic images of 107 consecutive patients having a cranial dural arteriovenous fistula with leptomeningeal venous drainage, based on a newly developed scheme. This scheme, symbolized with the acronym "DES," groups the dural shunts according to three factors: directness and exclusivity of leptomeningeal venous drainage and signs of venous strain. According to the combination of the three factors, eight different groups were distinguished. All analyzed cases could be assigned to one of these groups. Directness of leptomeningeal venous drainage expresses the exact site of the shunt (bridging vein vs sinus wall), whereas exclusivity expresses venous outlet restrictions. All bridging vein shunts had a direct leptomeningeal venous drainage. Almost all bridging vein shunts and all "isolated" sinus shunts had an exclusive leptomeningeal venous drainage. Venous strain, manifested as ectasia and/or congestion, denotes the decompensation of the cerebral venous system due to the shunt reflux. The comparison of the presented concept with the currently used classifications highlighted the advantages of the former and the weaknesses of the latter.

Cranial dural arteriovenous shunts. Part 1. Anatomy and embryology of the bridging and emissary veins.

We reviewed the anatomy and embryology of the bridging and emissary veins aiming to elucidate aspects related to the cranial dural arteriovenous fistulae. Data from relevant articles on the anatomy and embryology of the bridging and emissary veins were identified using one electronic database, supplemented by data from selected reference texts. Persisting fetal pial-arachnoidal veins correspond to the adult bridging veins. Relevant embryologic descriptions are based on the classic scheme of five divisions of the brain (telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon). Variation in their exact position and the number of bridging veins is the rule and certain locations, particularly that of the anterior cranial fossa and lower posterior cranial fossa are often neglected in prior descriptions. The distal segment of a bridging vein is part of the dural system and can be primarily involved in cranial dural arteriovenous lesions by constituting the actual site of the shunt. The veins in the lamina cribriformis exhibit a bridging-emissary vein pattern similar to the spinal configuration. The emissary veins connect the dural venous system with the extracranial venous system and are often involved in dural arteriovenous lesions. Cranial dural shunts may develop in three distinct areas of the cranial venous system: the dural sinuses and their interfaces with bridging veins and emissary veins. The exact site of the lesion may dictate the arterial feeders and original venous drainage pattern.

Cranial dural arteriovenous shunts. Part 4. Clinical presentation of the shunts with leptomeningeal venous drainage.

Cranial dural arteriovenous fistulae have been classified into high- and low-risk lesions mainly based on the pattern of venous drainage. Those with leptomeningeal venous drainage carry a higher risk of an aggressive clinical presentation. Recently, it has been proposed that the clinical presentation should be considered as an additional independent factor determining the clinical course of these lesions. However, dural shunts with leptomeningeal venous drainage include a very wide spectrum of inhomogeneous lesions. In the current study, we correlated the clinical presentation of 107 consecutive patients harboring cranial dural arteriovenous shunts with leptomeningeal venous drainage, with their distinct anatomic and angiographic features categorized into eight groups based on the "DES" (Directness and Exclusivity of leptomeningeal venous drainage and features of venous Strain) concept. We found that among these groups, there are significant angioarchitectural differences, which are reflected by considerable differences in clinical presentation. Leptomeningeal venous drainage of dural sinus shunts that is neither direct nor exclusive and without venous strain manifested only benign symptoms (aggressive presentation 0%). On the other end of the spectrum, the bridging vein shunts with direct and exclusive leptomeningeal venous drainage and venous strain are expected to present aggressive symptoms almost always and most likely with bleeding (aggressive presentation 91.5%). Important aspects of the above correlations are discussed. Therefore, the consideration of leptomeningeal venous drainage alone, for prediction of the clinical presentation of these shunts appears insufficient. Angiographic analysis based on the above concept, offers the possibility to distinguish the higher- from the lower-risk types of leptomeningeal venous drainage. In this context, consideration of the clinical presentation as an additional independent factor for the prediction of their clinical course seems superfluous and possibly misleading. Topography is connected to the clinical presentation of the dural shunts inasmuch as the former determines the venous anatomy and the angioarchitectural features of the lesions.

Cranial dural arteriovenous shunts. Part 2. The shunts of the bridging veins and leptomeningeal venous drainage.

Leptomeningeal venous drainage of cranial dural arteriovenous fistulae is the most important determinant of adverse clinical course. Factors that predispose to its occurrence have not been adequately addressed in the literature. In the present study, we investigated the relation of shunt location to the development of leptomeningeal venous drainage, with regard to the bridging veins. Angiographic data of 211 consecutive patients with cranial dural arteriovenous fistulae treated over 19 years were analyzed. Dural shunts with leptomeningeal venous drainage were found in 107 patients; of these, 71 patients had pure leptomeningeal venous drainage (Borden type 3). The angioarchitecture of the shunt, including pattern of arterial feeders, relation with the bridging veins, primary venous drainage, and venous outflow restrictions were recorded. After analysis of the 71 Borden type 3 shunts with exclusive leptomeningeal venous drainage, three patterns emerged. The commonest was the fistula engaging a bridging vein that had lost its connection to the parent sinus into which it previously drained; it was characterized by an arterial network of feeders converging onto the wall of a bridging vein, with leptomeningeal venous reflux. The other patterns were those of "isolated" sinus segment characterized by arterial feeders converging on to the wall of the dural sinus with leptomeningeal venous reflux following the opacification of the sinus and fistulae in the vicinity of the cribriform plate with two subtypes. The main angioarchitectural features of the 36 Borden type 2 shunts with mixed sinusal-cortical venous drainage were the presence of a diffuse arterial network of vessels converging onto a site in the wall of the dural sinus, with leptomeningeal venous reflux following the opacification of the sinus. In this group, four exceptions were noticed with arterial feeders converging onto a bridging vein and having a mixed venous drainage to the cortical venous system and the sinuses. We concluded that the exact location of the shunt with regard to the bridging veins is a key factor in the development of leptomeningeal venous drainage. Cranial dural arteriovenous fistulae (CDAVFs) of either Borden type 2 or 3 do not constitute a homogeneous group. The great majority of these shunts present thrombotic phenomena.

Transarterial onyx embolization of cranial dural arteriovenous fistulas: long-term follow-up.

Endovascular therapy with liquid embolic agents is a common treatment strategy for cranial dural arteriovenous fistulas. This study evaluated the long-term effectiveness of transarterial Onyx as the single embolic agent for curative embolization of noncavernous cranial dural arteriovenous fistulas. We performed a retrospective review of 40 consecutive patients with 41 cranial dural arteriovenous fistulas treated between March 2006 and June 2012 by using transarterial Onyx embolization with intent to cure. The mean age was 57 years; one-third presented with intracranial hemorrhage. Most (85%) had cortical venous drainage. Once angiographic cure was achieved, long-term treatment effectiveness was assessed with DSA and clinical follow-up. Forty-nine embolization sessions were performed; 85% of cranial dural arteriovenous fistulas were treated in a single session. The immediate angiographic cure rate was 95%. The permanent neurologic complication rate was 2% (mild facial palsy). Thirty-five of the 38 patients with initial cure underwent short-term follow-up DSA (median, 4 months). The short-term recurrence rate was only 6% (2/35). All patients with occlusion at short-term DSA undergoing long-term DSA (median, 28 months) had durable occlusion. No patient with long-term clinical follow-up (total, 117 patient-years; median, 45 months) experienced hemorrhage. Transarterial embolization with Onyx as the single embolic agent results in durable long-term cure of noncavernous cranial dural arteriovenous fistulas. Recurrence rates are low on short-term follow-up, and all patients with angiographic occlusion on short-term DSA follow-up have experienced a durable long-term cure. Thus, angiographic cure should be defined at short-term follow-up angiography instead of at the end of the final embolization session. Finally, long-term DSA follow-up may not be necessary if occlusion is demonstrated on short-term angiographic follow-up.

Aneurysmal Dilatation of Anterior Cranial Fossa Dural Arteriovenous Fistula: Three Cases

Aneurysmal dilatation of anterior cranial fossa dural arteriovenous fistula is a rare malformation with a unique and complex angio-architecture profile. Clinical manifestations, diagnosis and treatment management of three patients with the malformation were retrospectively analyzed. Preoperative examinations revealed all three patients suffered from aneurysmal dilatation; two of them were treated with surgical clipping of the fistula as well as removing of the aneurysm, and cured; one patient died of delayed surgical operation and other complications in two weeks. MRI examination could be used for early diagnosis and cerebral angiography could further confirm the diagnosis. To achieve a favorable outcome for patients the malformation has to be treated as early as possible by surgery or interventional therapy. doi: http://dx.doi.org/10.4021/jnr230e

MR Selective Flow-Tracking Cartography: A Postprocessing Procedure Applied to Four-dimensional Flow MR Imaging for Complete Characterization of Cranial Dural Arteriovenous Fistulas

To assess the feasibility of a selective flow-tracking cartographic procedure applied to four-dimensional (4D) flow imaging and to demonstrate its usefulness in the characterization of dural arteriovenous fistulas (DAVFs). Institutional review board approval was obtained, and all patients provided written informed consent. Eight patients (nine DAVFs) underwent 3.0-T magnetic resonance (MR) imaging and digital subtraction angiography (DSA). Imaging examinations were performed within 24 hours of each other. 4D flow MR imaging was performed by using a 4D radial phase-contrast vastly undersampled isotropic projection reconstruction pulse sequence with an isotropic spatial resolution of 0.86 mm (5 minutes 35 seconds). Two radiologists independently reviewed images from MR flow-tracking cartography and reported the location of arterial feeder vessels and the venous drainage type and classified DAVFs according to the risk of rupture (Cognard classification). These results were compared with those at DSA. Quadratic weighted κ statistics with their 95% confidence intervals (CIs) were used to test intermodality agreement in the identification of arterial feeder vessels, draining veins, and Cognard classification. Interreader agreement for shunt location on MR images was perfect (κ = 1), with good-to-excellent interreader agreement for arterial feeder vessel identification (κ = 0.97; 95% CI = 0.92, 1.0), and matched in all cases with shunt location defined at DSA. There was good-to-excellent agreement between MR cartography and DSA in the definition of the main feeding arteries (κ = 0.92; 95% CI = 0.83, 1.0), presence of retrograde flow in dural sinuses (κ = 1), presence of retrograde cortical venous drainage (κ = 1), presence of venous ectasia (κ = 1), and final Cognard classification of DAVFs (κ = 1, standard error = 0.35). MR selective flow-tracking cartography enabled the noninvasive characterization of cranial DAVFs.

MR Selective Flow-Tracking Cartography: A Postprocessing Procedure Applied to Four-dimensional Flow MR Imaging for Complete Characterization of Cranial Dural Arteriovenous Fistulas

Purpose To assess the feasibility of a selective flow-tracking cartographic procedure applied to four-dimensional (4D) flow imaging and to demonstrate its usefulness in the characterization of dural arteriovenous fistulas (DAVFs). Materials and Methods Institutional review board approval was obtained, and all patients provided written informed consent. Eight patients (nine DAVFs) underwent 3.0-T magnetic resonance (MR) imaging and digital subtraction angiography (DSA). Imaging examinations were performed within 24 hours of each other. 4D flow MR imaging was performed by using a 4D radial phase-contrast vastly undersampled isotropic projection reconstruction pulse sequence with an isotropic spatial resolution of 0.86 mm (5 minutes 35 seconds). Two radiologists independently reviewed images from MR flow-tracking cartography and reported the location of arterial feeder vessels and the venous drainage type and classified DAVFs according to the risk of rupture (Cognard classification). These results were compared with those at DSA. Quadratic weighted κ statistics with their 95% confidence intervals (CIs) were used to test intermodality agreement in the identification of arterial feeder vessels, draining veins, and Cognard classification. Results Interreader agreement for shunt location on MR images was perfect (κ = 1), with good-to-excellent interreader agreement for arterial feeder vessel identification (κ = 0.97; 95% CI = 0.92, 1.0), and matched in all cases with shunt location defined at DSA. There was good-to-excellent agreement between MR cartography and DSA in the definition of the main feeding arteries (κ = 0.92; 95% CI = 0.83, 1.0), presence of retrograde flow in dural sinuses (κ = 1), presence of retrograde cortical venous drainage (κ = 1), presence of venous ectasia (κ = 1), and final Cognard classification of DAVFs (κ = 1, standard error = 0.35). Conclusion MR selective flow-tracking cartography enabled the noninvasive characterization of cranial DAVFs. © RSNA, 2013 Online supplemental material is available for this article.

Endovascular treatment of 170 consecutive cranial dural arteriovenous fistulae: results and complications

This study aims to evaluate a single-center experience with endovascular treatment of cranial dural arterievenous fistulae (CDAVF). The clinical and radiological records of 170 consecutive patients harboring a CDAVF and treated endovascularly in a 16-year period were reviewed. A variety of data related to demographics, features of the lesion, treatment, outcome, and follow-up were analyzed with emphasis to the results and complications. Half of the lesions had cortical venous drainage (CVD) in the initial angiographic investigation, whereas 26% had exclusively CVD. Sixty-seven percent of our patients presented with benign symptoms and 33% with aggressive symptoms. In 60.5% of the patients with benign lesion (without CVD), an anatomic cure in the immediate postinterventional angiogram without complication or permanent morbidity was achieved, whereas 69% of the patients with aggressive lesions (with CVD) had an anatomic cure in the postinterventional final angiogram with all permanent-morbidity cases belonging to this group. The average of endovascular operation sessions per patient was 1.2. In a mean follow-up period of 2.8years, the overall complete occlusion rate was 85.5% (78% for the benign group and 89.5% for the aggressive group) and clinical cure and/or improvement rate of 93%. The operative mortality was zero, and permanent neurologic morbidity was 2.3%. In 73% of our cases, N-butyl cyanoacrylate (NBCA) was used as the only or main embolic material. Endovascular embolization is the treatment of choice for CDAVF. High rates of good anatomical and clinical results, associated with very low operative complication rate can be achieved with few embolization sessions. Although mastering of a permanent embolic material is important, the therapeutic strategy should be individulized and not material based.

Onyx is associated with poor venous penetration in the treatment of spinal dural arteriovenous fistulas

Background and purposeThe use of Onyx has become the mainstream for the treatment of cranial dural arteriovenous fistulas (AVFs) and arteriovenous malformations, but the reported success for type I spinal...