Embolization of intracranial dural arteriovenous fistulas with Onyx-18

Aneurysm of the Artery of Wollschlaeger and Wollschlaeger

The Artery of Wollschlaeger and Wollschlaeger (AWW) is a non-eloquent, tentorial branch of the superior cerebellar artery (SCA). Coursing posteriorly from an intradural origin, the AWW passes through the ambient cistern and supplies the medial tentorium. Due to its small diameter, the AWW is often only identified in the context of secondary dilation from pathologies such as dural arteriovenous fistulas (DAVF). Herein, we report the first case, to our knowledge, of an aneurysm of the AWW associated with a posterior fossa DAVF Swift identification and diagnosis followed by cautious treatment of both the aneurysm and fistula were critical to avert rupture and optimize outcomes, avoiding potential hemorrhagic complications.

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

BACKGROUND

The purpose of this study was to evaluate the technical efficacy and safety of transvenous Onyx embolization for dural arteriovenous fistulas (DAVFs) with concomitant transvenous balloon protection of the venous sinus when transarterial route failed or was not feasible.

METHODS

Between September 2010 and December 2016, thirty-six patients presenting with intracranial DAVFs underwent transvenous balloon-assisted Onyx embolization. The technical efficacy, treatment-related complications, and angiographic and clinical outcomes were reviewed from our prospectively maintained DAVF database.

RESULTS

According to the Cognard Classification, 11 patients presented with clinically symptomatic Cognard type I; 11 cases with Cognard type IIa; 10 cases with Cognard type IIb; and 4 cases with Cognard type IIa+b. Complete angiographic occlusion of the DAVFs at the latest follow-up (mean 18 months after transvenous embolization) was achieved in 28 patients (77.8%), near-complete angiographic occlusion with minimal residual fistula in 5 patients (13.9%) and significant flow reduction of the DAVF in 2 patients (5.6%) and residual fistula for further treatment in 1 (2.8%) patient. Total clinical cure or remission of the pretreatment symptoms was achieved in 31 patients (31/36, 86.1%; 26 and 5 cases respectively). Affected venous sinus was preserved in 28 patients, intentionally occluded in 7 patients and gradually occluded in 1 patient. There were no immediate or long-term persistent complications after treatment.

CONCLUSIONS

Transvenous Onyx embolization of dural arteriovenous fistulas with combined transvenous balloon protection of the venous sinus is safe and effective in achieving high occlusion rate, low embolization-related complications and satisfactory clinical outcomes.

Intracranial Dural Arteriovenous Fistulas with Cortical Venous Drainage: Radiosurgery as an Effective Alternative Treatment

OBJECTIVE

To evaluate the clinical and radiological outcome of Gamma Knife radiosurgery (GKS) in treatment of intracranial dural arteriovenous fistula (DAVF) with cortical venous drainage (CVD) and compare it with the outcome of endovascular therapy.

METHODS

Patients who underwent GKS or endovascular therapy for intracranial DAVF with CVD over 10 years (January 2007 to December 2016) at the All India Institute of Medical Sciences, New Delhi, were included. Demographics, clinical presentation, imaging details, and follow-up clinical status were reviewed retrospectively. Clinical follow-up was conducted once every 6 months. Radiological follow-up using digital subtraction angiography was performed at a mean 24 months after intervention. Patients with clinical follow-up of <1 year were excluded from the study.

RESULTS

The study included 35 patients (26 in embolization group and 9 in GKS group) who had intracranial DAVF with CVD were included in the study. Clinical improvement was seen in 77.78% of the patients who received GKS and 57.7% of the patients who underwent embolization (P = 0.431). Complete obliteration of DAVF was seen in 55.56% of the patients in the GKS group and 57.7% of the patients in the embolization group (P = 1). GKS was at least as effective as embolization in terms of clinical and radiological outcome in treatment of intracranial DAVF with CVD.

CONCLUSIONS

Contrary to popular perception, GKS should be considered as an effective first-line treatment alternative of intracranial DAVF with CVD.

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

Context

Endovascular therapy is currently the most common treatment approach for intracranial dural arteriovenous fistula (DAVF), followed by microsurgery. Gamma Knife radiosurgery (GKS) is usually reserved as the last modality of treatment of intracranial DAVF.

Aim

To evaluate the clinical and radiological outcome of GKS in the treatment of DAVF without CVD.

Subjects and Methods

This series includes patients who underwent GKS for intracranial DAVF without CVD over 10 years (Jan 2007 to Dec 2016) in All India Institute of Medical Sciences, New Delhi. Their demographic profile, clinical presentation, imaging details, GKS details, and follow-up clinical status were obtained retrospectively. Clinical follow-up, along with radiological assessment using MRI every 6 months was done after GKS. DSA was performed once MRI strongly suggested obliteration of DAVF. Patients who had a clinical follow-up of less than 1 year were excluded from the study.

Results

5 patients (4 males and 1 female) who had DAVF without CVD were included the study. The mean age was 44.8 years. All patients had complete obliteration of fistula on digital subtraction angiography (DSA) at a mean duration of 24 months post GKS. All patients had complete resolution of symptoms at the last follow-up.

Conclusions

Gamma Knife surgery is the most effective and the safest treatment modality for dealing with DAVFs without CVD. Instead of reserving it as the last resort for patients with DAVF without CVD, it should be considered as the gold standard treatment for DAVFs without CVD.

Outcomes After Onyx Embolization as Primary Treatment for Cranial Dural Arteriovenous Fistula in the Past Decade

RATIONALE AND OBJECTIVES

This retrospective single-center study aims to evaluate endovascular therapy (EVT) of cranial dural arteriovenous fistulas (dAVF) with ethylene vinyl alcohol (EVOH) copolymer (Onyx) regarding occlusion rates, complications, and recurrences.

MATERIAL AND METHODS

From January 2008 to April 2018, 75 patients with dAVF (41 men, 34 women; mean age 56 years) underwent EVT with the nonadhesive liquid embolic agent as primary treatment. Patient records and angiograms were reviewed for demographic data, symptoms, fistula type and size, number of EVTs, amount of embolic material, occlusion rates, and recurrences.

RESULTS

Seventy-five patients with dAVFs were primarily embolized with EVOH in 96 EVTs. According to the Merland-Cognard classification the majority of dAVFs treated were type 4 (42.7%), followed by type 2a (18.7%), type 2a+b (17.3%), type 1 (8%), type 2b (5.3%), type 3 (5.3%), and type 5 (2.7%). Complete occlusion (CO) of the dAVF was achieved in 45/75 (60%) of cases after a single EVT and in 58 (77%) patients after one or several EVTs. Seven patients (9%) required additional surgical therapy for CO. Successful treatment was achieved for 70/75 (93%) patients including 10 (13%) patients with residual dAVFs type 1-2a. Recurrence after CO occurred in one (1.3%) patient and four (5.3%) patients remained refractory to therapy with dAVFs type > 2a. Procedure-related permanent morbidity occurred in 4/75 (5.3%) patients.

CONCLUSION

For more than a decade transarterial EVOH embolization has established as the first-line treatment for cranial dAVFs with high cure rates and low rates of complications and recurrences. Additional neurosurgical therapy is rarely required for curative treatment.

Embolization of cranial dural arteriovenous fistulas in the liquid embolic era: A Sydney experience

Endovascular management of dural arteriovenous fistulas has become a mainstay of treatment. In particular, modern techniques have allowed greater fistula penetration and likelihood of complete obliteration. However, the efficacy of newer agents has not been quantified outside of predominantly small case reports and case series. Furthermore, the Australian experience with fistula embolization has yet to be reported in the literature. To this aim, we performed a retrospective review of our endovascular management of a large cohort of cranial dural arteriovenous fistulas in the liquid embolic era. This retrospective case series included ninety-six consecutive patients of any Cognard grade, treated between 2005 and 2016. Liquid embolic agents were used exclusively in eighty-three cases. The overall complete obliteration rate was 89.6% with a residual fistula rate of 2%, and complication rate of 8.3%. This Sydney, Australia cohort demonstrates excellent treatment effect and safety outcomes and thus supports the primary treatment of this condition by endovascular means.

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

PURPOSE

This 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 METHODS

Eleven 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.

RESULTS

Forty-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.

CONCLUSION

Four-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.

Delayed dural arteriovenous fistula after microvascular decompression for hemifacial spasm

Dural arteriovenous fistula (AVF) is very rare, acquired lesion that may present with intracranial hemorrhage or neurological deficits. The etiology is not completely understood but dural AVF often has been associated with thrombosis of the involved dural sinuses. To our knowledge, this is the first well documented intracranial hemorrhage case caused by dural AVF following microvascular decompression for hemifacial spasm. A 49-year-old male patient had left microvascular decompression of anterior inferior cerebellar artery via retrosigmoid suboccipital craniotomy. The patient was in good condition without any residual spasm or surgery-related complications. However, after 10 months, he suffered sudden onset of amnesia and dysarthria. Computed tomography and magnetic resonance imaging revealed the presence of dural AVF around the left transverse-sigmoid sinus. The dural AVF was treated with Onyx® (ev3) embolization. At the one-year follow up visit, there were no evidence of recurrence and morbidity related to dural AVF and its treatment. This case confirms that the acquired etiology of dural AVF may be associated with retrosigmoid suboccipital craniotomy for hemifacial spasm, even though it is an extremely consequence of this procedure.

Arteriovenous malformation in the brain: a theoretical study explaining the behavior of liquid embolic agents during endovascular treatment

There is no theoretical study on blood flow in brain arteriovenous malformation (AVM). We present a numerical theory on AVM and liquid embolic agent AVM embolization. Darcy's law was used to compute flow relations for brain AVMs. Maag's formula was used to explain the diffuse patterns of N-butyl-2-cyanoacrylate (NBCA) and ethylene-vinyl alcohol copolymer (EVOH) in brain AVMs. According to Darcy's law, the instantaneous blood flow rate through an AVM is directly proportional to the pressure drop between two places in the AVM and indirectly proportional to the distance between them. The greater the pressure gradient (through the AVM), the greater the discharge rate, and the discharge rate of blood will often differ through different AVM (or even through the same AVM, in a different direction) even if the same pressure gradient exists in both cases. Subsequent to Darcy's initial discovery, Maag found that the radius of NBCA or EVOH diffusion is inversely proportional to their viscosity. Darcy's Law and Maag's formula could be used to analyze flow patterns of brain AVM and liquid embolic agent behavior in AVM near ideal.

Characteristics and long-term outcome of 251 patients with dural arteriovenous fistulas in a defined population

OBJECT

Management of dural arteriovenous fistulas (DAVFs) has changed during the last decades due to increased knowledge of their pathophysiology and natural history as well as advances in treatment modalities. The authors describe the characteristics and long-term outcome of a large consecutive series of patients with DAVFs.

METHODS

Altogether 251 patients with 261 DAVFs were treated in 2 of the 5 neurosurgery departments at Helsinki and Kuopio University Hospitals between 1944 and 2006. Clinical data and radiological examinations were reviewed to assess patients' overall long-term clinical outcome.

RESULTS

The detection rate of DAVFs increased markedly in the 1970s and again in the 1990s when digital subtraction angiography was introduced. The incidence of DAVFs in a defined southern Finnish population was 0.51 per 100,000 individuals per year, which represents 32% of all the brain arteriovenous malformations. In the early part of the series, DAVFs were treated by proximal ligation of the feeding arteries. Later, most of the patients underwent preoperative embolization and subsequent craniotomy, and since 2000 stereotactic radiosurgery has been increasingly used in the treatment of DAVFs. Fifty-nine percent of the 261 fistulas were totally occluded. Treatment-related major complications were seen in 21 patients.

CONCLUSIONS

The advances in diagnostic methods (digital subtraction angiography, CT, and MRI) increased the detection rate of DAVFs, and as treatment modalities developed, the results of treatment and outcome of patients markedly improved with the introduction of endovascular techniques and stereotactic radiosurgery. Microsurgery is of limited use in DAVFs resistant to other treatment modalities.

The limitations and risks of transarterial Onyx injections in the treatment of grade I and II DAVFs

BACKGROUND AND OBJECTIVE

Embolization of grade III-V intracranial DAVFs using Onyx is feasible with promising results, indicating stability at the time of mid-term follow-up. This article is to evaluate the role of transarterial Onyx embolization in the treatment of grade I and II intracranial dural arteriovenous fistulas (DAVFs), including its limitations and risks.

METHODS

We retrospectively studied consecutive 26 patients (8 women and 18 men) treated for an grade I and II intracranial DAVF since 2006 in whom a transarterial approach was attempted with Onyx-18 embolization. There were 18 transverse-sigmoid sinus, 4 cavernous sinus, 2 superior sagittal sinus, 1 inferior petrosal sinus and 1 intradiploic fistulas. Five fistulas were Type I, 8 were Type IIa, and 13 were Type IIa+b, according to the Cognard classification. The mean clinical follow-up period was 15.6 months.

RESULTS

Anatomic cure was proven in 13 patients (50%) and clinical cure was obtained in 17 cases (65.4%). These 13 cures were achieved after a single procedure. All these 13 patients underwent a follow-up angiography, which has confirmed the complete cure. Partial occlusion was obtained in 13 patients. Complications were as follows: 2 cardiac Onyx migration, 2 reflexive bradyarrythmia, 1 transient visual hallucination, 2 transient fifth nerve palsies and 1 permanent seventh nerve palsy in inferior petrosal sinus DAVF.

CONCLUSIONS

Based on this experience, grade I and II intracranial DAVFs may be treated with transarterial Onyx embolization to reduce the shunted blood flow and to facilitate subsequent transvenous embolization or surgery.

Venous anastomotic circle, multiple varices and oculomotor palsy--a rare coincidence

Oculomotor nerve palsy due to a venous varix arising from flow anomalies caused by a dural arteriovenous fistula (AVF) is a rare phenomenon. We report a case of surgical third nerve palsy with a rare underlying AVF as the cause and discuss in detail the patho-anatomy and its significance. A tentorial dural AVF mimicking the arterial circle was found with multiple varix formation causing compressive oculomotor palsy. This was treated successfully with Onyx™ injection with a satisfactory angiographic result and complete resolution of symptoms.

Isolated hypoglossal nerve palsy due to endovascular treatment of a dural arteriovenous fistula with Onyx-18

We describe a patient with dural arteriovenous fistula (DAVF) treated with Onyx-18 who developed isolated hypoglossal nerve palsy. This is the first case of isolated hypoglossal nerve palsy caused by Onyx-18 embolization. This complication suggests that over embolization with Onyx-18 in the treatment of hypoglossal canal DAVFs should be avoided, and transvenous embolization may be safer. Furthermore, prednisolone therapy should be carried out in the prophase of nerve palsy.

Transarterial and transvenous embolization for cavernous sinus dural arteriovenous fistulae

We report on the safety and efficacy of trans-arterial and transvenous Onyx embolization in the treatment of dural arteriovenous fistulae (DAVFs) of the cavernous sinus. We reviewed the findings from a retrospectively database for 22 patients with cavernous sinus DAVFs who were treated with either transarterial Onyx embolization alone (n = 8) or transarterial and transvenous Onyx embolization (n = 14) over a four year period. The mean follow-up period after endovascular treatment was 21.6 months (range 3-42 mths). Total number of embolizations was 27 for 22 patients. Two patients were treated transvenously after transarterial embolization. All 22 patients (100%) experienced improvement of their clinical symptoms. All 22 patients (100%) experienced total obliteration of their DAVFs, as documented by angiography performed at a mean follow-up of 5.8 months after the last treatment. No patient experienced a recurrence of symptoms after angiography showed DAVF obliteration. One patient exhibited temporary deterioration of ocular symptoms secondary to venous hypertension after near total obliteration; one had transient V cranial nerve deficit related to transarterial embolization, and two patients exhibited transient III and VI cranial nerve weakness related to transvenous embolization. Two patients experienced recurrent symptoms after incomplete transarterial embolization and underwent transvenous embolization at three and four months. Both patients achieved clinical and angiographic cures. Transarterial and transvenous embolization with Onyx, whenever possible, proved to be a safe and effective management for patients with cavernous sinus DAVFs.

Transverse-sigmoid sinus dural arteriovenous fistulae

Transverse-sigmoid sinus dural arteriovenous fistulae are abnormal arteriovenous communications within the dural wall of the transverse-sigmoid sinuses. They present with a variety of clinical features, ranging from benign bruits to intracranial hemorrhage and neurologic deficits. The presentation and natural history of these fistulae are largely determined by the pattern of venous drainage. Knowledge of natural history and careful study of the angioarchitecture by angiography is therefore mandatory for correct management of these lesions. In this review, anatomy and pathology, principles of management, and the various factors that influence treatment decisions are discussed, with a focus on endovascular therapy. Indications for endovascular treatment, therapeutic goals, approaches, and techniques are reviewed. The role of surgical treatment is also briefly discussed.

Transvenous embolization of cavernous sinus dural arteriovenous fistulas using detachable coils and Glubran 2 acrylic glue via the inferior petrosal sinus approach

OBJECTIVES

To describe the technique, efficacy, and safety of transvenous embolisation (TVE) of cavernous sinus arteriovenous fistulas (CSDAVFs) via the inferior petrosal sinus (IPS) with detachable coils and acrylic glue.

METHODS

Spontaneous unilateral CSDAVFs were confirmed by cerebral angiography in eight patients, with angiographic patency of the ipsilateral IPS in three and angiographic non-visualisation of the ipsilateral IPS in five. There were two patients with complete occlusion of the ipsilateral internal jugular vein (IJV). TVE with detachable coils and acrylic glue were performed through a femoral vein and an IPS approach.

RESULTS

TVE viaipsilateral IPS was successfully performed in all eight patients in our group. The number of detachable coils for each patient ranged from 2 to 8 (mean, 5.0). Angiography immediately after TVE showed complete occlusion of the CSCAVFs in seven patients and nearly complete occlusion in one. Complete recovery of clinical symptoms was achieved in all eight patients. No recurrence of clinical symptoms was observed at follow-up.

CONCLUSIONS

Transvenous embolisation via an IPS approach is a highly efficient and safe treatment for CSDAVFs. Embolisation with a combination of coils and acrylic glue may help to achieve complete occlusion of fistulas with fewer coils.