Cerebral arteriovenous fistulas induced by dural arteriovenous shunts

Dural arteriovenous shunts and pial arteriovenous fistulas are uncommonly associated. Their etiology, pathogenesis, and natural history are still unclear and are likely different. We present three cases of high-flow dural arteriovenous shunts associated with pial arteriovenous fistulas and discuss their pathogenesis, anatomic association, and angioarchitecture. We propose that venous steal effect in the dural sinus secondary to the high-flow dural arteriovenous shunt induced the pial arteriovenous fistulas. Treatment of the high-flow dural arteriovenous shunts and the induced pial arteriovenous fistulas are discussed.     

Multiple dural arteriovenous fistulas of the cranium and spine

Dural arteriovenous fistulas are acquired lesions that usually involve the dura around the cavernous sinus. The transverse, sigmoid, and superior sagittal sinuses may be affected occasionally. With the exception of bilateral cavernous sinus dural arteriovenous fistulas, the simultaneous occurrence of dural arteriovenous fistulas at two locations is rare. Among 105 patients evaluated for dural arteriovenous fistulas, we identified seven patients with fistulas at two sites. The age of the patients ranged from 27 to 74 years. Presentation was related to hemorrhage in three patients, loss of vision in four, and a bruit and headaches in one. Patients were treated with combined surgical and endovascular techniques. All treated lesions were completely closed with no mortality or permanent morbidity. The presence of multiple fistulas must be considered in patients being evaluated for dural arteriovenous fistulas. Patients with multiple fistulas usually present with life-threatening hemorrhages or acute neurologic decline; the risk factor for hemorrhages, including those related to venous outflow obstruction, is high in patients with multiple dural arteriovenous fistulas.     

Diagnostik und Therapie duraler arteriovenöser Fisteln

Intradural arteriovenous fistulas can occur at any location within the dura mater. Patients can be clinically asymptomatic or show symptoms ranging from mild up to fatal hemorrhaging. Previously dural arteriovenous fistulas were often dealt with surgically via a variety of access routes. Since recent years there is now the possibility to close most dural arteriovenous fistulas by endovascular embolisation. In addition, stereotactic radiation therapy is available, which can also achieve good results especially in combination with surgery.     

Spinale durale arterioven?se Fisteln

Spinal dural arteriovenous fistulas are rare spinal vascular malformations which can cause progressive paraparesis and paraplegia if not treated. As symptoms are unspecific diagnosis is often delayed and clinical outcome is dependent on early therapy. While magnetic resonance imaging (MRI) is the first choice imaging procedure, selective spinal digital subtraction angiography is necessary to analyze the angioarchitecture and to plan the treatment. This article provides an overview on the epidemiology, etiology, clinical aspects and imaging features as well as therapeutic aspects of spinal dural arteriovenous fistulas. Knowledge of spinal vascular anatomy is the basis for understanding spinal dural arteriovenous fistulas.     

Embolization of dural arteriovenous fistulas with interlocking detachable coils.

Our clinical experience with interlocking detachable coils for the embolization of high-flow dural arteriovenous fistulas is reported. Interlocking detachable coils are useful for transarterial and transvenous embolizations of dural arteriovenous fistulas because (a) immediate coil detachment is possible, (b) the coils can be replaced easily, (c) detached coils rarely migrate, and (d) fewer interlocking detachable coils than conventional fiber coils are required for successful embolization.     

Endovascular treatment of dural arteriovenous fistula involving marginal sinus with emphasis on the routes of transvenous embolization

Introduction  

Dural arteriovenous fistulas involving marginal sinus are relatively rare. Transvenous embolization is a curative treatment of choice for them. Regional anatomy surrounding the marginal sinus comprises complex craniocervical bony structures and abundant venous interconnections. Therefore, dural arteriovenous fistulas involving marginal sinus may have various routes for a transvenous approach. The purpose of this article was to analyze endovascular treatment of marginal sinus dural arteriovenous fistulas with emphasis on the routes of transvenous embolization.     

经动脉途径应用Onyx栓塞治疗复杂硬脑膜动静脉瘘

目的：探讨经动脉途径应用Onyx栓塞治疗复杂硬脑膜动静脉瘘的可行性。方法：2006年6月-2009年10月应用Onyx经动脉途径栓塞治疗复杂硬脑膜动静脉瘘11例,回顾分析其临床资料及随访结果。结果：11例患者共经15次栓塞,栓塞结束时解剖治愈率81.8%（9/11）,治疗后神经功能缺失9%（1/11）,无致残及死亡。其中8例3-6个月接受DSA随访,1例复发。结论：经动脉途径应用Onyx栓塞治疗复杂硬脑膜动静脉瘘,可获得高的即时解剖治愈率而伴随的临床并发症发生机会低,因而是安全、可行的。     

Diagnosis of spinal dural arteriovenous fistula with multidetector row computed tomography: a case report

Spinal dural arteriovenous fistulas are a rare cause of myelopathy. Nonspecific symptoms may delay the diagnosis. Magnetic resonance imaging and spinal angiography are routinely used to establish the diagnosis. In our case abnormalities on magnetic resonance imaging only suggested spinal dural arteriovenous fistulas. Multidetector row computed tomography (MRCT) led to the diagnosis which was confirmed by angiography.     

Computed tomographic and digital subtraction angiography evaluation of ophthalmic-ethmoidal artery dural arteriovenous fistula

Ophthalmic-ethmoidal dural arteriovenous fistula (DAVFs) is a rare type of dural arteriovenous fistulas and usually presenting with spontaneous subarachnoid hemorrhage, subdural hemorrhage or ocular symptoms. We present a case of a 59-year old gentleman presenting with acute headache, vomiting and generalized weakness. CT study of the brain revealed a large left frontal hematoma and abnormal aneurysmal sac with dilated cortical vein, communicating with the superior sagittal sinus. Conventional angiography confirmed diagnosis of ruptured ophthalmic-ethmoidal DAVF, resulting in a frontal intra-axial hemorrhage. Anterior fossa DAVFs are extremely rare, difficult to diagnose and treat. CT angiography is initial method of diagnosis, but digital substruction angiography remains the gold standard of confirming dural fistulas.     

Double spinal dural arteriovenous fistulas

We present a patient with double spinal dural arteriovenous fistulas revealed by progressive myelopathy. Numerous dilated veins extending along the entire length of the spinal cord were found on MR imaging. Angiography showed a first spinal dural fistula at the level of T7 with descending venous drainage and a second spinal dural fistula at the level of T5 with ascending venous drainage. Both fistulas were cured by therapeutic embolization.     

Cerebrovascular malformations

The lesions to be considered in this course on cerebrovascular malformations are arteriovenous malformations of the brain, cavernous malformations, capillary telangiectasia and dural arteriovenous fistulas.     

Comparison of Time-Resolved and First-Pass Contrast-Enhanced MR Angiography in Pretherapeutic Evaluation of Spinal Dural Arteriovenous Fistulas

BACKGROUND AND PURPOSE:Different MRA techniques used to evaluate spinal dural arteriovenous fistulas offer unique advantages and limitations with regards to temporal and spatial resolution. The purpose of this study was to compare the efficacy and interobserver agreement of 2 commonly used contrast-enhanced spinal MRA techniques, multiphase time-resolved MRA and single-phase first-pass MRA, in assessment of spinal dural arteriovenous fistulas.MATERIALS AND METHODS:Retrospective review of 15 time-resolved and 31 first-pass MRA studies in patients with clinical suspicion of spinal dural arteriovenous fistula was performed by 2 independent, blinded observers. DSA was used as the reference standard to compare the diagnostic performance of the 2 techniques.RESULTS:There were 10 cases of spinal dural arteriovenous fistula in the time-resolved MRA group and 20 in the first-pass MRA group. Time-resolved MRA detected spinal dural arteriovenous fistulas with sensitivity and specificity of 100% and 80%, respectively, with 100% correct-level localization rate. First-pass MRA detected spinal dural arteriovenous fistulas with sensitivity and specificity of 100% and 82%, respectively, with 87% correct-level localization rate. Interobserver agreement for localization was excellent for both techniques; however, it was higher for time-resolved MRA. In 5 cases, the site of fistula was not included in the FOV, but a prominent intradural radicular vein was observed at the edge of the FOV.CONCLUSIONS:Multiphase time-resolved MRA and single-phase first-pass MRA were comparable in diagnosis and localization of spinal dural arteriovenous fistulas and demonstrated excellent interobserver agreement, though there were more instances of ambiguity in fistula localization on first-pass MRA.

Spinal dural arteriovenous fistulas (SDAVFs) represent an abnormal connection between a radiculomeningeal artery and a radicular vein, typically on the dural sleeve adjacent to the nerve root. The arterialized radicular vein causes regurgitation of blood flow to the perimedullary venous plexus, resulting in increased venous pressure and congestion.¹ Although SDAVFs are a treatable cause of myelopathy,² the diagnosis remains challenging because the clinical and conventional MR imaging features are nonspecific. As a result, misdiagnosis and delay in diagnosis are common, which may result in additional disability.³MRA is useful for confirming the diagnosis and for localizing SDAVFs to expedite DSA.^4,5 DSA is ultimately the “criterion standard” for diagnosis of this condition, but the number of injections and the time required to perform this study can be reduced with the knowledge of the level involved, provided by MRA. The contrast-enhanced spinal MRA techniques useful for evaluation of SDAVFs are broadly of 2 types: first-pass and time-resolved. These differ with regards to temporal and spatial resolution. The purpose of this study was to compare the efficacy and interobserver agreement of multiphase time-resolved MRA (TR-MRA) and single-phase first-pass MRA (FP-MRA) in assessment of SDAVFs.     

Surgical transvenous embolization of a cortically draining carotid cavernous fistula via a vein of the sylvian fissure.

Percutaneous transvenous embolization is one of the most effective treatments of intracranial dural arteriovenous fistulas (AVFs) involving the dural sinuses. We present a unique case of surgical transvenous embolization in a 48-year-old man with a dural AVF of the cavernous sinus who presented with intracerebral hematoma. The dural AVF drained only into the vein of the sylvian fissure on angiography. Transvenous embolization via the vein of the sylvian fissure during craniotomy obliterated the AVF completely.     

Transvenous embolization as the primary therapy for arteriovenous fistulas of the lateral and sigmoid sinuses.

PURPOSEWe report on the evolution in one institution from transarterial embolization for the treatment of dural arteriovenous fistulas of the lateral and sigmoid sinuses to the safer and more durable technique of transvenous endovascular therapy for the majority of these lesions.METHODSArterial, venous, and combined embolizations were performed for 24 fistulas of the lateral and sigmoid sinuses between August 1991 and December 1996. The patients were followed up clinically for 2 to 63 months, with a mean follow-up period of 30 months.RESULTSNine patients had arterial embolization without transvenous treatment: five of the nine had angiographic and clinical obliteration of their fistulas; two of the nine, with unusual lesions, required surgery; and the remaining two had recurrences and were not retreated. Seven patients had both arterial embolization and coil embolization (packing) of the dural sinuses, four after arterial embolization had failed to cure the lesions; in all seven, the fistulas were obliterated angiographically and clinically. Eight patients had only transvenous coil embolization of the dural sinuses; all eight were cured. One patient had minimal arterial embolization during the primary venous embolization procedure. Complications occurred in two patients, both related to arterial embolization with ethanol.CONCLUSIONOur experience suggests that arterial embolization of dural arteriovenous fistulas of the lateral and sigmoid sinuses is associated with a low cure rate and high rate of recurrence, whereas transvenous endovascular packing of the involved segment of the sinus results in a high cure rate that obviates arterial embolization or surgical excision in most cases.     

Changing Clinical and Therapeutic Trends in Tentorial Dural Arteriovenous Fistulas: A Systematic Review

BACKGROUND AND PURPOSE:Tentorial dural arteriovenous fistulas are characterized by a high hemorrhagic risk. We evaluated trends in outcomes and management of tentorial dural arteriovenous fistulas and performed a meta-analysis evaluating clinical and angiographic outcomes by treatment technique.MATERIALS AND METHODS:We performed a comprehensive literature search for studies on surgical and endovascular treatment of tentorial dural arteriovenous fistulas. We compared the proportion of patients undergoing endovascular, surgical, and combined endovascular/surgical management; the proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas; and proportion of patients with good neurologic outcome across 3 time periods: 1980–1995, 1996–2005, and 2006–2014. We performed a random-effects meta-analysis, evaluating the rates of occlusion, long-term good neurologic outcome, perioperative morbidity, and resolution of symptoms for the 3 treatment modalities.RESULTS:Twenty-nine studies with 274 patients were included. The proportion of patients treated with surgical treatment alone decreased from 38.7% to 20.4% between 1980–1995 and 2006–2014. The proportion of patients treated with endovascular therapy alone increased from 16.1% to 48.0%. The proportion of patients presenting with ruptured tentorial dural arteriovenous fistulas decreased from 64.4% to 43.6%. The rate of good neurologic outcome increased from 80.7% to 92.9%. Complete occlusion rates were highest for patients receiving multimodality treatment (84.0%; 95% CI, 72.0%–91.0%) and lowest for endovascular treatment (71.0%; 95% CI, 56.0%–83.0%; P < .01). Long-term good neurologic outcome was highest in the endovascular group (89.0%; 95% CI, 80.0%–95.0%) and lowest for the surgical group (73.0%; 95% CI, 51.0%–87.0%; P = .03).CONCLUSIONS:Patients with tentorial dural arteriovenous fistulas are increasingly presenting with unruptured lesions, being treated endovascularly, and experiencing higher rates of good neurologic outcomes. Endovascular treatment was associated with superior neurologic outcomes but lower occlusion rates.

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal direct shunts between the dural arteries and dural veins.¹ The shunt is located in the intracranial dura mater with venous drainage directed to the dural venous sinuses or cortical veins. Dural arteriovenous fistulas account for 10%–15% of all intracranial vascular shunts.^1,2 Tentorial dural arteriovenous fistulas (TDAVFs) constitute only 4% of DAVFs and are characterized by a high hemorrhagic risk. Because of this, these lesions are treated aggressively on diagnosis.^3–5Traditionally, surgical resection was the only treatment available for these lesions. However, endovascular embolization, either alone or in combination with surgery, is increasingly used.⁶ Stereotactic radiosurgery is also increasingly used as an adjunct to surgical and endovascular treatment.⁷ We performed a systematic review of the literature on surgical and endovascular treatment of TDAVFs from 1980 to 2014. The purpose of our study was the following: 1) to determine whether there was a shift from primarily surgical treatments to endovascular and multimodality treatment during this time period, 2) to determine whether the proportion of patients presenting with ruptured TDAVFs during this time period has changed, 3) to determine whether the rate of good neurologic outcome has changed, and 4) to evaluate clinical and angiographic outcomes in endovascular, surgical, and combined treatments by performing a random-effects meta-analysis.     

Transvenous embolization of a dural arteriovenous fistula of the cavernous sinus through the contralateral pterygoid plexus

We report a new transvenous endovascular route for treatment of dural arteriovenous fistulas of the cavernous sinus. The cavernous sinus was approached from the contralateral pterygoid plexus and embolization of a dural fistula was performed successfully with Guglielmi detachable coils. Received: 16 June 1997 Accepted: 6 August 1997     

Embolization of branches arising from the cavernous portion of the internal carotid artery

Seven patients with vascular disease (four with cavernous and two with transverse sinus dural fistulas and one with a facial arteriovenous malformation, all supplied primarily from cavernous branches of the internal carotid artery) underwent subselective catheterization and embolization. Ten branches were catheterized (seven meningohypophyseal trunks and three inferolateral trunks) and eight branches were embolized. The embolic agents were as follows: polyvinyl alcohol particles in five, hypertonic glucose in two, and liquid adhesive in one. All four cavernous sinus dural fistulas were occluded after embolization. In the two transverse sinus fistulas, the goal of embolization was to obliterate the tentorial supply prior to surgery. This goal was achieved in both cases. In the remaining patient, who had a large facial arteriovenous malformation and recurrent epistaxis, the embolization obliterated the cavernous supply to the nasal cavity and the patient remains hemorrhage-free. Despite one complication, which occurred in the first case when a thrombus formed and dislodged, resulting in an embolic stroke, this study shows that subselective catheterization and embolization can obliterate lesions of the branches arising from the cavernous internal carotid artery.     

Intraarterial digital subtraction angiography of spinal arteriovenous malformations

Intraarterial digital subtraction angiography (DSA) in two patients with spinal dural arteriovenous fistulas demonstrated the major feeding arteries and the venous drainage of the respective malformations. However, the dural component of the malformations--which distinguishes them from intradural malformations--could not be recognized, nor was normal cord vasculature demonstrated. In a patient with an intradural arteriovenous malformation (AVM), only major arterial feeders were demonstrated. Intraarterial DSA provides essential anatomic information with an increased margin of safety in spinal AVMs, but supplemental selective arteriography, conventional or digital, also is currently required.     

Dural arteriovenous fistula involving the posterior condylar canal

Although dural arteriovenous fistulas (DAVFs) occur in any structure that is covered by the dura mater, DAVFs at the posterior condylar canal have not been reported. We present a DAVF that involves the posterior condylar canal and drains into the posterior condylar vein and the occipital sinus, which was treated by selective transvenous embolization. Knowledge of venous anatomy of the craniocervical junction and careful assessment of the location of the arteriovenous fistula can contribute to successful treatment.     

Medial tentorial dural arteriovenous fistula: A rare cause of bithalamic oedema

A 39-year-old man was admitted after 1 week of headaches and cognitive changes. CT scan showed bithalamic hypodensities, corresponding to bithalamic vasogenic oedema. Punctuate hemorrhage was present, with foci of thalamic enhancement. CT angiography raised the suspicion of arteriovenous shunt. Digital subtraction angiography confirmed a medial falcotentorial dural arteriovenous fistula. Complete embolization was performed using liquid embolic agent. Although tentorial dural fistulas have already been described as a cause of bithalamic oedema and subacute dementia, they are not generally included in pathologies implied in this radiologic pattern.