Management strategies for anterior cranial fossa (ethmoidal) dural arteriovenous fistulas with an emphasis on endovascular treatment

Transpalpebral/Blepharoplasty Incision and Supraorbital Craniotomy for the Treatment of Ethmoidal Dural Arteriovenous Fistulas: A Case Series

BACKGROUND AND OBJECTIVES

Inherent complex angioarchitecture associated with ethmoidal dural arteriovenous fistulas (dAVFs) can make endovascular treatment methods challenging. Many surgical approaches are accompanied by unfavorable cosmetic results such as facial scarring. Blepharoplasty incision of the eyelid offers a minimal, well-hidden scar compared with other incision sites while offering the surgeon optimal visualization of pathogenic structures. This case series aims to report an initial assessment of the safety and efficacy of supraorbital craniotomy by blepharoplasty transpalpebral (eyelid) incision for surgical disconnection of ethmoidal dAVFs.

METHODS

Retrospective chart review was conducted for all patients who underwent blepharoplasty incision and craniotomy for disconnection of ethmoidal dAVFs at our institution between October 2011 and February 2023. Patient charts and follow-up imaging were reviewed to report clinical and angiographic outcomes as well as periprocedural and follow-up complications.

RESULTS

Complete obliteration and disconnection of ethmoidal dAVF was achieved in all 6 (100%) patients as confirmed by intraoperative angiogram with no resulting morbidity or mortality. Periprocedural complications included one case of transient nasal cerebrospinal fluid leak that was self-limiting and resolved before discharge without intervention.

CONCLUSION

Surgical treatment for ethmoidal dAVFs, specifically by transpalpebral incision and supraorbital craniotomy, is a safe and effective treatment option and affords the surgeon greater access to the floor of the anterior fossa when necessary. In addition, blepharoplasty incision addressed patient concerns for facial scarring compared with other incision sites by creating a more well-hidden, minimal scar in the natural folds of the eyelid for patients with an eyelid crease.

Treatment of Ethmoidal Dural Arteriovenous Fistulae Using Supraorbital Keyhole Subfrontal Approach

Due to a unique cortical venous drainage pattern without sinus drainage, ethmoidal dural arteriovenous fistula (DAVF) are uncommon cerebral vascular lesions that carry a high risk of brain bleeding and neurologic deficit. Surgical intervention has been found to have a lower complication rate and a more satisfactory obliteration rate than endovascular treatment among the various DAVF treatment options. The supraorbital keyhole subfrontal approach is one of the least invasive and appropriate surgical techniques for addressing the anterior fossa vascular lesion in eDAVFs. We describe two men, ages 60 and 71, who underwent this surgical intervention to treat asymptomatic Cognard type IV eDAVFs. Complete obliteration with a detached fistulous point and skeletonization was accomplished with the aid of intraoperative neuronavigation. Thus, we suggest that a suitable surgical method for the treatment of eDAVFs would be to use a supraorbital keyhole subfrontal approach.

Transvenous retrograde pressure cooker technique for embolization of an ethmoidal dural arteriovenous fistula

SummaryEthmoidal dural arteriovenous fistulas (DAVFs) are rare lesions, accounting for approximately 10% of intracranial DAVFs.1 2 As ethmoidal DAVFs commonly demonstrate cortical venous drainage, treatment is always warranted.2-6 Endovascular transvenous embolization has been increasingly reported as an effective and safe treatment for ethmoidal DAVFs, and since occlusion of the central retinal artery and resulting blindness are not a concern, it has an advantage over transarterial embolization.3-6 To ensure curative embolization, we adopted the transvenous retrograde pressure cooker technique (RPCT), creating a plug with n-butyl cyanoacrylate (NBCA) in the draining vein to allow a more comprehensive and efficient injection of Onyx (Medtronic, MN) while avoiding excessive reflux.7 8 In this technical video (video 1), we report the first case using the transvenous RPCT for successful Onyx embolization of an ethmoidal DAVF, with emphasis on the technical nuances of the RPCT and important tips to avoid periprocedural complications. neurintsurg;16/7/742/V1F1V1Video 1 Video demonstrating Onyx embolization of an ethmoidal dural arteriovenous fistula using the transvenous retrograde pressure cooker technique.

Transarterial embolization for anterior cranial fossa dural arteriovenous fistulas: a retrospective single-center study

BACKGROUND

Clip ligation of anterior cranial fossa (ACF) dural arteriovenous fistulas (DAVFs) is the traditionally accepted first-line treatment. Endovascular treatment for ACF DAVFs may achieve good outcomes as endovascular techniques advance. Here we report the clinical and angiographic outcomes in patients with ACF DAVFs who underwent transarterial embolization (TAE) as first-line treatment.

METHODS

Over a 20-year period, 87.0% (40/46) of patients received TAE as first-line treatment. The clinical presentation, angiographic features, treatment strategy, and clinical and angiographic outcomes are described in this article.

RESULTS

Forty patients underwent TAE as first-line treatment. There were 36 men and 4 women, with a mean age of 55.6 (55.6±7.4) years. A total of 64 embolization attempts were performed. The middle meningeal artery (66.7%, 12/18) and the ophthalmic artery (54.2%, 13/24) were the most frequently used arterial access routes for complete embolization. The second option was the sphenopalatine artery (46.7%, 7/15). Complications, that is, retinal ischemia, occurred in one patient (2.5%). The total immediate complete occlusion rate for TAE was 82.5% (33/40). Two patients needed surgery for incomplete embolization. When followed up (90%, 36/40), one patient (2.8%, 1/36) reported worsening symptoms due to retinal ischemia following TAE. Although fewer than 50% of the patients received digital subtraction angiography follow-up, there were no recurrences.

CONCLUSIONS

We show that TAE is safe and effective in the treatment of ACF DAVFs in this study of 40 patients, making it a viable alternative to surgical ligation and transvenous embolization. More research is needed to compare these various treatment modalities.

Feasibility, safety, and efficacy of endovascular treatment of anterior cranial fossa dural arteriovenous fistulas: a systematic review and meta-analysis with a subanalysis for Onyx

Dural Arteriovenous Fistulas (dAVFs) of the anterior cranial fossa (ACF) are uncommon but carry a high risk of hemorrhage and pose substantial treatment challenges. Recent advancements in endovascular treatment (EVT), including the introduction of novel liquid embolic agents, have markedly bolstered EVT's role in managing ACF-dAVFs, with notable series published in the last five years. We aimed to assess the feasibility, safety, and efficacy of EVT for ACF-dAVFs. We searched Medline, Scopus, Web of Science, and Cochrane Library databases following PRISMA guidelines. Eligible studies included those with ≥ 5 patients undergoing embolization of ACF-dAVFs, detailing both angiographic and clinical outcomes. We used single proportion analysis with 95% confidence intervals under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Publication bias was assessed by funnel-plot analysis and Egger's test. Outcomes included complete occlusion following embolization, unsuccessful endovascular embolization attempts, incomplete occlusion following embolization, symptom resolution or clinical improvement following embolization, recurrence; procedure-related complications, morbidity, and mortality. Additionally, a subanalysis for studies exclusively utilizing Onyx™ embolic system was done. Eighteen studies comprising 231 ACF-dAVF were included. Unsuccessful endovascular embolization attempts rate was 2%. Complete occlusion rate was 85%, with 4% of complications. Incomplete occlusion rate was 10%. Successfully embolized patients experienced either symptom resolution or clinical improvement in 94% of cases. Morbidity and mortality rates were 1% and 0%, respectively. Onyx subanalyses showed an overall rate of 0% for unsuccessful attempts, 95% for complete occlusion, and 5% for incomplete occlusion. Symptom resolution or clinical improvement was 98% and recurrence rate was 0%. EVT for ACF-dAVF is highly feasible, effective, and safe, with a low rate of complications, morbidity, and mortality. The subanalyses focusing on Onyx embolizations revealed superior efficacy and safety outcomes compared to the findings of the primary analyses involving all included studies.

Surgical considerations and techniques using intraoperative indocyanine green angiography for ethmoidal dural arteriovenous fistula

OBJECTIVE

This study aims to investigate the efficacy of microsurgery with intraoperative indocyanine green (ICG) angiography as a treatment approach for ethmoidal dural arteriovenous fistula (DAVF).

METHODS

Between January 2010 and July 2021, our institution encountered a total of eight cases of ethmoidal DAVF. In each of these cases, microsurgical treatment was undertaken utilizing a bilateral sub-frontal interhemispheric approach, with the aid of intraoperative ICG angiography.

RESULTS

ICG angiography identified bilateral venous drainage with single dominance in four cases (50%) of ethmoidal DAVF, a finding that eluded detection during preoperative transfemoral cerebral angiography (TFCA). The application of microsurgical treatment, in conjunction with intraoperative ICG angiography, resulted in consistently positive clinical outcomes for all patients, as evaluated using the Glasgow Outcome Scale (GOS) at the 6-month postoperative follow-up assessment; six patients showed GOS score of 5, while the remaining two patients attained a GOS score of 4.

CONCLUSIONS

The use of intraoperative ICG angiography enabled accurate identification of both dominant and non-dominant venous drainage patterns, ensuring complete disconnection of the fistula and reducing the risk of recurrence.

Transvenous embolization of noncavernous dural arteriovenous fistulas (dAVFs): A systematic review and meta-analysis

BACKGROUND

Intracranial dural arteriovenous fistulas (dAVFs) are abnormal connections between arteries and veins within the dura mater. Various treatment modalities, such as surgical ligation, endovascular intervention, and radiosurgery, aim to close the fistulous connection. Although transvenous embolization (TVE) is the preferred method for carotid-cavernous fistulas, its description and outcomes for noncavernous dAVFs vary. This has prompted a systematic review and meta-analysis to comprehensively assess the effectiveness of TVE in treating noncavernous dAVFs, addressing variations in outcomes and techniques.

METHODS

We searched PubMed and Embase, spanning from the earliest records to December 2022, to identify pertinent English-language articles detailing the utilization of TVE. We focused on specific procedural details, outcomes, and complications in patients older than 18 years. The data collected and analyzed comprised the sample size, number of fistulas, publication specifics, presenting symptoms, fistula grades, and pooled rates of embolizations, outcomes, follow-up information, and complications.

RESULTS

From a total of 565 screened articles, 15 retrospective articles encompassing 166 patients spanning across seven countries met the inclusion criteria. Their Newcastle-Ottawa scores ranged from 6 to 8. Intraprocedural complication rate was 10% (95% confidence interval [CI] = 5.9-17.1) and in-hospital postprocedural complication rate was 5.4% (95% CI = 2.8-10.6). Prevalence of in-hospital mortality was 5.5% (95% CI = 2.9-10.6). Complication rate during follow-up was 8.6% (95% CI = 4.7-15.7) with fistula rupture occurring in 5.5% (95% CI = 2.6-11.6) of patients. Complete obliteration rate at final angiographic follow-up was 94.9% (95% CI = 90.3-99.9). Symptoms improved in 95% (95% CI = 89.8-100) of patients at final follow-up.

CONCLUSION

To our knowledge, we present the first meta-analysis assessing obliteration rates, outcomes, and complications of TVE for dAVFs. Our analysis highlights the higher (>90%) complete obliteration rates. Large prospective multicenter studies are needed to better define the utility of TVE for noncavernous dAVFs.

Simultaneous bilateral application of the Scepter mini balloon microcatheter for occlusion of ethmoidal dural arteriovenous fistulas

Ethmoidal dural arteriovenous fistulas are a rare entity accounting for 10 % of all dAVFs.3-6 Haemorrhage occurs in up to 91 % of cases, which is a particularly high risk and warrants therapeutic intervention.8-9 Endovascular treatment for these fistulas using the conventional detachable microcatheter technique is associated with certain limitations and risks; 8.3 % rate of incomplete obliteration and an 8.3 % rate of complications. Complications include reflux of liquid embolic agent, posterior ischaemic optic neuropathy, acute visual loss, and small subdural haematoma secondary to a micro-perforation.8,10-12 We present our recent experience with the Scepter Mini Balloon Microcatheter for the endovascular treatment of ethmoidal dural arteriovenous fistulas in 3 patients, involving bilateral simultaneous inflation of the balloon. It demonstrates a novel application of this technology with good outcomes. It supports the use of this microcatheter in treating ethmoidal dural arteriovenous fistulas endovascularly, either as a first-line option or as an adjunct to surgery.

Copolymer liquid embolization of dural arteriovenous fistulas: A 20-year single-center experience

BACKGROUND AND PURPOSE

Dural arteriovenous fistulas (DAVFs) with cortical venous drainage (CVD) carry significant risks of cerebral ischemia and intracranial hemorrhage. Endovascular treatment (EVT) using Onyx, a copolymer-based liquid embolic material, has become the preferred approach. However, the optimal treatment strategy for anterior cranial fossa DAVFs remains debated.

METHODS

This retrospective study analyzed outcomes of EVT for DAVFs in a single center from 2002 to 2023. Patient data including demographics, clinical status, angiographic findings, embolization techniques, and outcomes were recorded. The results of the anterior fossa malformations were analyzed separately afterward.

RESULTS

A total of 195 DAVFs were included in the study. The most common presenting symptom was hemorrhage (41%), most fistulas were located in the transverse and sigmoid sinus region (48%), and the majority of DAVFs had direct CVD (78%). Transarterial embolization with Onyx was the preferred treatment strategy in majority of cases (92%). Overall, 94% of patients showed improvement or stability on the modified Rankin Scale. Two patients died due to rebleeding after partial DAVF embolization. Onyx demonstrated higher immediate complete occlusion rate compared to other embolic materials (88% vs. 35%). Overall, 91% of fistulas were closed at the last follow-up. Ten anterior fossa DAVFs were treated, resulting in clinical improvement and complete occlusion in all cases.

CONCLUSION

Based on the results of our study, we believe that a cure of DAVFs, including those in the anterior fossa, can be achieved in more than 90% of cases through transarterial Onyx embolization, given long-term clinical experience.

Intracranial Non-Sinus-Type Dural Arteriovenous Fistulas Could Be Curable by Transarterial Embolization or Transvenous Embolization with Liquid Embolic Material

Objective

Recently, the occlusion rate of transarterial embolization (TAE) for intracranial non-sinus-type dural arteriovenous fistulas (NSDAVFs) has improved after ONYX was introduced. Additionally, when TAE for NSDAVF is unsuccessful, transvenous embolization (TVE) has become available as an alternative treatment. We investigated the factor for the favorable occlusion rate of endovascular treatment for NSDAVF at our institutions.

Methods

Two hundred and twenty-seven patients with intracranial dural arteriovenous fistulas (DAVFs) were treated at our institutions between September 2014 and October 2022. The patients diagnosed with NSDAVF in all DAVFs who underwent endovascular treatment were included. The clinical characteristics, angiographical outcomes, and clinical outcomes of patients who underwent endovascular treatment were evaluated.

Results

Thirty-eight patients had intracranial NSDAVF (tentorial: 23 cases, parasagittal-convexity: 7, anterior cranial fossa: 6, middle cranial fossa: 2). Our participants' mean age was 64.8 ± 11.3 years, and 31 (81.6%) of them were males. Patients' symptoms were as follows: asymptomatic (24), hemorrhage (10), tinnitus (3), and trigeminal neuralgia (1). TAE and TVE were performed on 35 and 3 patients, respectively. The rate of immediate angiographical occlusion was 84.2% (32/38). The follow-up angiographical occlusion rate in 6 months was 88.5% (31/35). Complications occurred in three cases. There was no morbidity or mortality after 30 days.

Conclusion

TAE using the combination of the new microcatheter and microguidewire and TVE in the case of difficult or failed TAE for NSDAVF could achieve high success rates and safety.

Endovascular treatment of anterior cranial base dural arteriovenous fistulas as a first-line approach: a multicenter study

OBJECTIVE

Anterior cranial fossa dural arteriovenous fistulas (DAVFs) have been almost exclusively considered as surgical lesions. However, new advances in endovascular technology have made the endovascular treatment (EVT) of ethmoidal DAVFs feasible. The aim of this study was to report the clinical and angiographic outcomes of patients harboring DAVFs of the anterior cranial fossa who had undergone EVT as a first-line approach.

METHODS

This was a retrospective study of a consecutive series of patients harboring anterior cranial base DAVFs who had undergone EVT as a first-line approach at four institutions. Angiographic follow-up was performed at 6 months. Immediate and late serious clinical events were assessed during follow-up, including death and stroke. Special emphasis was given to visual status before and after the treatment.

RESULTS

Between 2008 and 2020, 37 patients with ethmoidal DAVFs were admitted to the participating centers. In 2 patients, EVT was not attempted; therefore, 35 patients underwent EVT as a first-line procedure. An isolated transarterial approach was performed in 19 (54.3%) patients. The transvenous approach was performed exclusively in 12 (34.3%) patients, and combined access was used in 4 (11.4%) patients. The most frequently used arterial access route was the ophthalmic artery in 82.6% of the patients. Immediately, complete angiographic occlusion was achieved in 31 (91.2%) of 34 patients whose treatment was accomplished. Six-month control angiography revealed that 30 (88.2%) DAVFs were totally occluded. Complications occurred in 3 (8.8%) patients, including 1 (2.9%) patient who had central retinal artery occlusion. No significant difference in complications or occlusion rates was noted between the transarterial and transvenous approaches.

CONCLUSIONS

Most anterior cranial base DAVFs can be successfully treated via an endovascular approach. Neurological and visual complications are rare, even if the ophthalmic artery is used as the primary access route. Efforts should be focused on prospectively comparing the results of EVT and surgical management.

Anterior cranial fossa osseous arteriovenous fistula of the crista galli with bone erosion: patient series

BACKGROUND

Although an anterior cranial fossa dural arteriovenous fistula (ACFdAVF) is thought to have a fistula on the dura near the olfactory groove, the detailed angioarchitecture remains unreported.

OBSERVATIONS

In case 1, a 65-year-old man was found to have an asymptomatic ACFAVF. His computed tomography angiography (CTA)-maximum intensity projection (MIP) showed the shunt point in the crista galli (CG), with the intradural drainer penetrating the destroyed bone of the CG. In case 2, a 78-year-old man had a past history of intracerebral hemorrhage and was found to have an ACFAVF. The rotational angiography (RA)-MIP showed the intraosseous fistula in the CG with the drainer passing through a tiny bone defect of the CG. In case 3, a 35-year-old man was investigated for epilepsy. The RA-MIP showed an osseous arteriovenous fistula (AVF) in the anterior cranial base, with the drainer penetrating the skull osteolytic site. In case 4, a 73-year-old woman was found to have an asymptomatic ACFAVF. Her RA-MIP showed the osseous AVF with the drainer penetrating the CG with bone erosion.

LESSSONS

All patients were diagnosed with anterior cranial fossa osseous AVF rather than dAVF, with bone erosion in the CG. These findings should be noted at the time of diagnosis and treatment.

Endovascular Management of Intracranial Dural AVFs: Transvenous Approach

In this third review article on the endovascular management of intracranial dural AVFs, we discuss transvenous embolization approaches. Transvenous embolization is increasingly popular and now the first-line approach for ventral dural AVFs involving the cavernous sinus and hypoglossal canal. In addition, transvenous embolization is increasingly used in lateral epidural dural AVFs in high-risk locations such as the petrous and ethmoid regions. The advantage of transvenous embolization in these locations is the ability to retrogradely embolize the draining vein and fistula while reducing the risk of ischemic cranial neuropathy or brain parenchymal infarction commonly feared from a transarterial approach. By means of coils ± ethylene-vinyl alcohol copolymer, transvenous embolization can achieve angiographic cure rates of 80%-90% in ventral locations. Potential complications include transient cranial neuropathy, neurologic deterioration due to venous outflow obstruction, and perforation while navigating pial veins. Transvenous embolization should be considered when dural AVFs arise in proximity to the vasa nervosum or extracranial-intracranial anastomoses.

Micro-balloon-assisted embolization of anterior cranial fossa dural arteriovenous fistula via a trans-ophthalmic approach — a technical report and case series

Purpose

Dural arteriovenous fistulas (dAVF) account for approximately 10–15% of all intracranial arteriovenous abnormalities. dAVFs carry a significant risk of mortality, particularly in cases of acute hemorrhage, of up to 10%. A small proportion of these dAVFs are found in the anterior cranial fossa (ACF), of which the rate of hemorrhage can be as high as up to 91%. The Scepter Mini (SM) is the smallest dual-lumen micro-balloon (MB) available for neurointerventional practice. It consists of a 2.8 French outer diameter, with a 2.2 mm × 9 mm semi-compliant balloon providing a working length of 165 cm. The SM is navigated with a 0.008-inch wire making it a particularly attractive tool accessible to the pedicles normally reached with liquid embolization micro-catheters.

Methods

Five consecutive patients over a 1-year period between 2020 and 2021 were evaluated and treated for ACF dAVF using a liquid embolization approach using the SM balloon. All patients were treated using ethylene–vinyl alcohol copolymer (EVOH), of which Squid 18 and/or Squid 12 were the chosen viscosities. Control angiograms were performed for all patients post-embolization.

Results

All patients demonstrated complete occlusion of the ACF dAVF on immediate post-treatment angiography. No immediate complications were encountered; particularly, there were no reports of visual field deficit in any of the patients.

Conclusion

The MB is a valuable adjunctive tool that can enhance the safety and efficacy of trans-ophthalmic embolization of ACF dAVFs, providing additional protection to the retinal and posterior ciliary arteries against unwanted reflux of liquid embolic agent.

Foramen Caecum Vein Involved in Dural Arteriovenous Fistula Fed by Sphenopalatine Arteries: A Case Report

Anterior cranial fossa (ACF) dural arteriovenous fistulas (ACF DAVFs) are an infrequent subtype of cranial DAVFs that are usually fed by the anterior ethmoidal artery (AEA) and ophthalmic artery (OA) branches. Due to the lack of dural venous sinus in the ACF, they directly drain into cortical veins, resulting in high bleeding tendency. For this reason, ACF DAVFs have to be treated regardless of whether they are symptomatic or not. A 74-year-old man, with hypertension history, came to our attention because of ear pain, dizziness, and impaired hearing for 2 months. No other pathological conditions have been found in his medical history. The patient underwent brain magnetic resonance imaging (MRI) scan and subsequently second level diagnostic investigations with digital subtraction angiography (DSA), showing a foramen caecum (FC) patency and a persistent, enlarged, arterialized FC vein (FCV) involved in an incidental ACF DAVF (Cognard IV), fed mainly by sphenopalatine arteries (SPAs) branches bilaterally. The patient underwent open surgery performed by small high frontal craniotomy with DAVFs complete closure and without any complications. To the best of our knowledge, this is the first case ever described of FCV persistence with involvement in an intracranial vascular malformation. It has been managed by surgical intervention that can be considered, despite the large skin incision, a minimally invasive approach with an excellent cosmetic result and minimal risk of complications.

Intracranial Hemorrhage from Dural Arteriovenous Fistulas: What Can We Find with CT Angiography?

(1) Background: Dural arteriovenous fistulas (DAVF) represent a rare acquired intracranial vascular malformation, with a variety of clinical signs and symptoms, which make their diagnosis difficult. Intracranial hemorrhage is one of the most serious clinical manifestations. In this paper the authors’ goal was to verify the accuracy and utility of contrast-enhanced brain CT angiography (CTA) for the identification and the characterization of dural arteriovenous fistulas (DAVFs) in patients who presented with brain hemorrhage compared to 3D digital subtraction angiography (3D DSA); (2) a retrospective study of 26 patients with DAVFs who presented with intracranial hemorrhage to our institution was performed. The information reviewed included clinical presentation, location and size of hemorrhage, brain CTA and 3D DSA findings; (3) results: 61% (16/26) of DAVFs were identified by CTA. The vast majority of patients were male (69%, 18/26) and the most common presenting symptom was sudden onset headache. All DAVFs had cortical venous drainage and about one-third were associated with a venous varix. The most common location was tentorial (73%, 19/26); (4) conclusions: CTA can represent a valid alternative diagnostic method to 3D DSA for the study of DAVF in the initial and preliminary diagnostic approach, especially in emergency situations. In fact, it represents a fast, inexpensive, non-invasive and above all, easily accessible and available diagnostic technique, unlike DSA or MRI, allowing to provide information necessary for the identification, classification and treatment planning of DAVFs.

Anterior interhemispheric approach for anterior fossa dural arteriovenous fistulas

Anterior fossa dural arteriovenous fistulas (AF-DAVF) usually display a cortical venous drainage and are therefore at risk for rupture. Microsurgery is traditionally considered in many centers as the first-line treatment since endovascular treatment (EVT) entails a lower cure rate and significant ophthalmic risks. The anterior interhemispheric approach (AIA), originally described by Mayfrank in 1996, seems to offer the effectiveness of microsurgery while limiting the risks related to subfrontal craniotomy. The objective of this study was to analyze the surgical outcomes of patients who underwent this surgical approach for the treatment of AF-DAVF. We hereby describe our 10 years' experience of patients treated for an AF-DAVF with this technique in our institution and retrospectively analyzed our results. In addition, we describe our operative technique and its specificities. Eleven patients with AF-DAVF were included in our study. The definitive cure of the fistula was confirmed in all cases with postoperative cerebral angiography. All patients had a good neurological outcome and no major complication occurred. Brain retractors were never used during surgery, the frontal sinus was never opened neither, and anosmia was never observed after surgery. Anterior interhemispheric approach seems to be safe and effective to treat AF-DAVF with lower risks than other surgical approaches. This technique could be more widely considered when facing such midline vascular lesion.

Mixed Pial-Dural Arteriovenous Malformation in the Anterior Cranial Fossa Mimicking Dural Arteriovenous Fistula

Mixed pial-dural arteriovenous malformation (MpdAVM) and dural arteriovenous fistula (dAVF) are rare entities in the anterior cranial fossa (ACF). As dural-pial vascular anastomosis can exist near the cribriform plate, MpdAVM with a small nidus, which cannot be apparently identified, can be logically indistinguishable from dAVF in ACF. A 71-year-old man was referred for evaluation of possible intracranial vascular malformation. Cerebral angiography revealed an arteriovenous shunt in the ACF. The lesion was fed by the bilateral ethmoidal arteries and right orbitofrontal artery, draining through the bilateral cortical veins to the superior sagittal sinus. As a nidus was not detected, dAVF was suspected. Venous interruption was planned with direct surgery. Intraoperatively, an arterial aggregation was observed in the right frontal lobe. The arterial aggregation seemed to be connected to the interrupted drainer in the right ACF. The arterial aggregation was removed and pathologically diagnosed as arteriovenous malformation. Postoperatively, intracerebral hemorrhage was confirmed, and postoperative cerebral angiography confirmed the resolved arteriovenous shunt. The intracranial hemorrhage was possibly due to the timing gap between drainer interruption and removal of the nidus. MpdAVM with a small nidus in the ACF can mimic dAVF. Clinicians must be aware that an unremoved nidus of MpdAVM may postoperatively result in fatal intracranial hemorrhage.

Transarterial embolization through the infraorbital artery of the ethmoidal dural arteriovenous fistula causing recurrent epistaxis: illustrative case

BACKGROUND

This report describes an ethmoidal dural arteriovenous fistula (DAVF) presenting with the unusual symptom of recurrent epistaxis and successfully treated with selective transarterial embolization through the infraorbital artery (IOA), which is the first time this route was used to the best of the authors’ knowledge, and reviews the literature focusing on the anatomical consideration of ethmoidal DAVFs causing epistaxis and its treatment approaches.

OBSERVATIONS

A 70-year-old man experienced recurrent intractable epistaxis that bled like a faucet turned on. Cerebral angiography revealed an ethmoidal DAVF supplied by the left anterior ethmoidal artery, both sphenopalatine arteries, both IOAs, and the right angular artery, which drained directly into the frontal cortical veins with a tortuous arterialized ectasia. Microaneurysms around the fistulous location where multiple feeding arteries converge were demonstrated and considered the likely source of the epistaxis. The fistula was completely occluded using transarterial Onyx embolization through the IOA, a branch of the internal maxillary artery. No further epistaxis appeared.

LESSONS

Although extremely rare, ethmoidal DAVFs should be included in the differential diagnosis of recurrent epistaxis. Ethmoidal DAVFs with bleeding sources in the ethmoid sinus and nasal cavity may cause epistaxis. It is important to properly diagnose and treat ethmoidal DAVFs presenting with epistaxis on the basis of a comprehensive anatomical understanding of extensive extracranial-extracranial and extracranial-intracranial anastomoses.

Efficacy and safety of embolization of dural arteriovenous fistulas via the ophthalmic artery

INTRODUCTION

Dural arteriovenous fistulae (DAVF) are vascular lesions with arteriovenous shunting that may be treated with surgical obliteration or endovascular embolization. Some DAVF, such as anterior cranial fossa DAVF (AC-DAVF) derive their arterial supply from ophthalmic artery branches in nearly all cases, and trans-arterial embolization carries a risk of vision loss. We determined the efficacy and safety of trans-ophthalmic artery embolization of DAVF.

MATERIALS AND METHODS

We performed a retrospective cohort study of all patients with DAVF treated by trans-ophthalmic artery embolization from 2012 to 2020. Primary outcome was angiographic cure of the DAVF. Secondary outcomes included vision loss, visual impairment, orbital cranial nerve injury, stroke, modified Rankin Scale at 90-days, and mortality.

RESULTS

12 patients met inclusion criteria (9 males; 3 females). 10 patients had AC-DAVF. Patient age was 59.7  ±  9.5 (mean ± SD) years. Patients presented with intracranial hemorrhage (4 patients), headache (4 patients), amaurosis fugax (1 patients), or were incidentally discovered (2 patients). DAVF Cognard grades were: II (1 patient), III (6 patients), and IV (5 patients). DAVF were embolized with Onyx (10 patients), nBCA glue (1 patient), and a combination of coils and Onyx (1 patient). DAVF cure was achieved in 11 patients (92%). No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision attributed to posterior ischemic optic neuropathy. 90-day mRS was 0 (10 patients) and 1 (2 patients).

CONCLUSIONS

Trans-ophthalmic artery embolization is an effective and safe treatment for DAVF.

Transnasal flow reduction in endovascular treatment for anterior cranial fossa dural arteriovenous fistula

Transarterial embolization (TAE) is a useful option for anterior cranial fossa–dural arteriovenous fistula (ACF–dAVF) as endovascular devices have progressed. Liquid agents are usually injected via a microcatheter positioned just proximal to the shunt pouch beyond the ophthalmic artery; however, high blood flow from the internal maxillary artery (IMA) often impedes penetration of embolic materials into the shunt pouch. Therefore, reducing blood flow from the IMA before embolization can increase the success rate. In the present case, to reduce blood flow from branches of the IMA, we inserted surgical gauze infiltrated with xylocaine and epinephrine into bilateral nasal cavities. Using this method, we achieved curative TAE with minimal damage to the nasal mucosa. Transnasal flow reduction is an easy, effective and minimally invasive method. This method should be considered in the endovascular treatment of ACF–dAVF, especially in patients with high blood flow from theIMA.

Endovascular treatment of anterior cranial fossa dural arteriovenous fistula: a multicenter series

PURPOSE

We report a multicenter experience using endovascular embolization as the first line approach for treatment of anterior cranial fossa (ACF) dural arteriovenous fistula (DAVF).

METHODS

All patients with DAVFs located in the anterior cranial fossa who were treated with endovascular technique as a first line approach were included. Demographics, clinical presentation, angioarchitecture, strategy, complications, immediate angiographic, and follow-up results were included in the analysis.

RESULTS

Twenty-three patients met the inclusion criteria (18 male and 5 female). Age ranged from 14 to 79 years (mean 53 years). Twelve patients presented with hemorrhage. Twenty-eight endovascular procedures were performed. The overall immediate angiographic cure rate after endovascular treatment was 82.6% (19/23 patients). The angiographic cure rate of the transvenous strategy was significantly superior to the transarterial strategy (p ≤ 0.001). There was 1 complication in 28 total procedures (3.6%). Angiographic follow-up was available in 21 out of the 23 patients with a mean of 25 months (range 2 to 108 months). In these 21 patients, the DAVF was completely cured in 20 (95%). At last follow-up, all patients had a modified Rankin scale (mRS) 0 to 2.

CONCLUSION

Our experience suggests that endovascular treatment for ACF DAVFs has an acceptable safety profile with high rates of complete occlusion, particularly with transvenous approach. Whenever possible, transvenous approach should be preferred over transarterial approach as first line strategy.

Anterior Cranial Fossa Dural Arteriovenous Fistulae - Angioarchitecture and Intervention

PURPOSE

Anterior cranial fossa (ACF) dural arteriovenous fistulae (DAVF) are rare, unique, and ominous. While surgical disconnection is considered as the favored management option, endovascular treatment has lately gained importance. We present a single institution experience of seven cases.

METHOD

A retrospective analysis was performed on the institutional patient database. Features analyzed were demographic details, symptoms, angioarchitecture, treatment course, angiographic results, procedural complications, and follow-up.

RESULTS

This study included seven patients. The age at presentation ranged from 5-67 years. Clinical symptomatology was as intracranial hemorrhage in 4 patients and headache, chemosis and seizures in one patient each. The fistulae were paramedian at the ACF base. All DAVFs were Cognard type 4. The arterial feeders were from the anterior ethmoidal branches of the ophthalmic artery in all cases (bilateral in n = 5), frontal branches of the middle meningeal artery (MMA) (n = 6), and multiple ECA branches. The arterial route was the choice for access. Complete fistula obliteration was achieved in all but one patient. A traversed vein underwent rupture in one patient. One patient suffered postsurgical hemorrhage. No clinical or angiographic recurrence was noted.

CONCLUSION

The DAVFs of the ACF are inherently high-grade lesions. Transorbital ECA-ICA branch anastomoses may be recruited as feeders. They may be best managed by multidisciplinary means personalized on an angioarchitectural basis. Endovascular embolization is safe and efficacious when performed through a navigable feeder from the frontal division of the MMA, which according to our interpretation is in anastomosis with the anterior falcine branch of the anterior ethmoidal artery.

Results of 1940 embolizations for dural arteriovenous fistulas: Japanese Registry of Neuroendovascular Therapy (JR-NET3)

OBJECTIVE

Embolization is the most common treatment for dural arteriovenous fistulas (dAVFs). A retrospective, multicenter observational study was conducted in Japan to clarify the nature, frequency, and risk factors for complications of dAVF embolization.

METHODS

Patient data were derived from the Japanese Registry of Neuroendovascular Therapy 3 (JR-NET3). A total of 40,169 procedures were registered in JR-NET3, including 2121 procedures (5.28%) in which dAVFs were treated with embolization. After data extraction, the authors analyzed complication details and risk factors in 1940 procedures performed in 1458 patients with cranial dAVFs treated with successful or attempted embolization.

RESULTS

Transarterial embolization (TAE) alone was performed in 858 cases (44%), and transvenous embolization (TVE) alone was performed in 910 cases (47%). Both TAE and TVE were performed in one session in 172 cases (9%). Complications occurred in 149 cases (7.7%). Thirty-day morbidity and mortality occurred in 55 cases (2.8%) and 16 cases (0.8%), respectively. Non-sinus-type locations, radical embolization as the strategy, procedure done at a hospital that performed dAVF embolization in fewer than 10 cases during the study period, and emergency procedures were independent risk factors for overall complications.

CONCLUSIONS

Complication rates of dAVF embolization in Japan were acceptable. For better results, the risk factors identified in this study should be considered in treatment decisions.

Anterior Cranial Fossa Dural Arteriovenous Fistula with Pial Arterial Supply

Anterior cranial fossa (ACF) dural arteriovenous fistulas (DAVFs) are mainly fed by the ethmoidal arteries and sometimes have pial arterial feeders. DAVFs with pial arterial supply in ACF are extremely rare because most of the reported cases of DAVFs with pial arterial supply are located at the transverse sigmoid sinus and tentorium. A 68-year-old male presented with dizziness. Angiography showed cortical venous reflex (CVR) through an ACF DAVF fed by both bilateral ethmoidal arteries and by the right orbitofrontal artery as a pial feeder. The ethmoidal feeders were disconnected by craniotomy. The pial arterial feeder from the anterior cerebral artery was not found during surgery, and disconnection of the draining vein was not performed. CVR showed a significant reduction after the surgery. After 2 years of follow-up, angiography revealed an increased shunt flow from the pial feeder. Endovascular treatment using n-butyl-2-cyanoacrylate was performed, resulting in the complete occlusion of the fistula. DAVFs with pial supply are reported to carry a high risk of perioperative complications because of the restriction of the venous outflow and retrograde thrombosis of the pial artery. Endovascular pial feeder occlusion after surgical dural arterial feeder disconnection might achieve a safe and effective outcome. With close follow-up, the recurrence of increased shunt flow may be an appropriate timing for additional treatment. This rare condition may offer a new insight into the mechanisms of pial feeder development.

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

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

Endovascular treatment for dural arteriovenous fistulas in the petroclival region

Petroclival region dural arteriovenous fistulas (DAVFs) are rare and difficult lesions to manage. They often have very complex anatomical structures and can be further divided into the superior petrosal sinus, petrous apex, inferior petrosal sinus, upper clival, and upper clival epidural-osseous DAVFs. Most petroclival region DAVFs should be treated due to their high Cognard grades. Currently, endovascular treatment (EVT) has become the first-line therapeutic option for petroclival region DAVFs. But not all the petroclival region DAVFs could be cured with EVT. When the arterial feeders are large or the DAVF is adjacent to the venous sinus, the success rate may be higher. In petroclival region DAVFs, if EVT can be performed successfully, satisfactory outcome can be anticipated. However, there are some inadvertent complications, which include cranial nerve palsy, subsequent sinus thrombosis, and migration embolization of the internal carotid artery and vertebral artery. Currently, a review of the EVT of petroclival region DAVFs is lacking. In this article, we performed a review of the relevant literature on this issue. In addition, some illustrative cases would be provided to elaborate these specific entities.

Embryology and anatomical variations of the ophthalmic artery

PURPOSE

The ophthalmic artery (OA) has one of the most complex anatomy and the most fascinating embryological development.

METHODS

The complexity of the embryologic development of the OA resides in the implication of three different embryological systems: the carotid system, the stapedial system, and the ventral pharyngeal system.

RESULTS

This explains very well the numerous variations in origin of the OA and the importance of vascular anastomoses developed with branches of the external carotid artery and with the middle meningeal artery.

CONCLUSION

In this review, authors propose a comprehensive description of different hypotheses on the embryologic development of the OA and, in a second part, explain all anatomical variations and clinical implications of this artery.

Cranial dural arteriovenous shunts: selection of the ideal lesion for surgical occlusion according to the classification system

BACKGROUND

The types of cranial dural arteriovenous fistulae (cDAVFs) that constitute good surgical candidates are unclear despite the use of classifications. We aimed to compare the DES classification with other classification schemes in identifying "ideal lesions for surgery." The DES scheme is based on two features: the level of the shunt (BVS, bridging vein shunt; DSS, dural sinus shunt; ISS, isolated sinus shunt; EVS, emissary vein shunt) and the type of leptomeningeal venous reflux (LVR) (direct, exclusive, strained).

METHODS

In this observational cohort study, the angiographies of 20 consecutive patients treated over 1 year were analyzed retrospectively. We defined cDAVFs as ideal for surgery, if cure may be achieved by disconnecting the arterialized draining vein through a single craniotomy. To evaluate the performance of each classification scheme in identifying the "ideal lesion for surgery," we carried out a sensitivity analysis of the Borden, Cognard, and DES schemes.

RESULTS

Eight lesions were Borden type 3 and 1 type 2, and 11 type 1. According to Cognard, 2 lesions were type IV, 2 type III, 1 type IIa+b, 11 type I, and 4 lesions could not be clearly classified. According to the DES scheme, 8 lesions were DSS, 4 BVS, 3 ISS, and 5 EVS. All 4 lesions classified as BVS in the DES were ideal lesions for surgery (sensitivity, specificity, PPV, NPV 100%). Not all high-grade lesions according to Borden were good surgical candidates.

CONCLUSION

The DES scheme, as opposed to other classifications, facilitates the therapeutic decision-making especially for selecting candidates for surgery.

Anterior cranial fossa dural arteriovenous fistula: Transarterial embolization from the ophthalmic artery as first-line treatment

OBJECTIVE

To retrospectively review the outcome of patients with dural arteriovenous fistula of the anterior cranial fossa (afDAVF) treated by transarterial embolization.

MATERIAL AND METHODS

Six consecutive patients were referred to our hospital for afDAVF treatment. After a multidisciplinary discussion, they underwent endovascular embolization with Onyx injection through the ophthalmic artery. Their clinical presentation, management and outcomes were retrospectively assessed.

RESULTS

All interventions were performed with the liquid embolic agent Onyx through the transarterial route from the ophthalmic artery to access the fistulous point. All patients showed a good outcome with complete afDAVF obliteration.

CONCLUSION

This study demonstrates that afDAVFs can be safely and completely obliterated by transarterial embolization via the ophthalmic artery.

Current status of endovascular treatment for dural arteriovenous fistulae in the anterior cranial fossa: A systematic literature review

Anterior cranial fossa (ACF) dural arteriovenous fistulae (DAVFs) are rare, and a systematic review of the literature is lacking. Such a review is necessary, however, so a systematic PubMed search of related studies was performed. Twenty-four studies were identified, reporting on 48 patients, of whom 39 had definite age and sex information and 33 (84.6%, 33/39) were male. The afflicted patients were between 37 and 80 years old (mean 55.6). Among the 48 patients, 28 (58.3%, 28/48) primarily presented with intracranial hemorrhage, 47 (97.9%, 47/48) had feeding arteries from the anterior ethmoidal artery (AEA) of the ophthalmic artery (OA), and 40 (83.3%, 40/48) had bilateral feeding arteries. All of the cases had high-grade Cognard classifications (III-IV). Among the 48 patients, 43 (89.6%, 43/48) had drainage into the superior sagittal sinus (SSS). In addition, 36 (75%, 36/48) patients were treated via transarterial embolization (TAE). Of these patients, 28 (77.8%, 28/36) were managed via the AEA of the OA. Another 12 (25%, 12/48) patients were treated via transvenous embolization (TVE), 11 of whom (91.7%, 11/12) were treated with the trans-SSS approach. Complete angiographic cure was achieved in 44 (91.7%, 44/48) patients, with 4 (8.3%, 4/48) patients suffering from postprocedural complications. All 48 patients had clear descriptions of follow-up outcomes, with 45 (93.8%, 45/48) patients having a good outcome. Thus, when treating ACF DAVFs, endovascular treatment (EVT) can completely obliterate the fistula point and correct the venous shunting. EVT is therefore an effective treatment for ACF DAVF. Although many complications can occur, this approach achieves good outcomes in most cases.

Dural arteriovenous fistula mimicking temporal arteritis

INTRODUCTION

Dural arteriovenous fistula (dAVF) is a very rare disease characterized by an abnormal vascular communication between arteries and veins in dural mater. It frequently presents with intracranial haemorrhage. Common presenting symptoms are headache and seizures.

CASE REPORT

Here we report a case of dAVF in which the patient's symptoms mimic a temporal arteritis in a 23-year-old woman. She presented with painful mass at forehead for 9 months with frontotemporal headache. Magnetic resonance imaging demonstrated dural arteriovenous fistula.

CONCLUSION

Since both diseases have different prognosis but similar presentation, it is important to ensure that there is no dural arteriovenous fistula in patient with suspected temporal arteritis.

Recurrent epistaxis due to cribriform plate dural arteriovenous fistula: are they related? Should the treatment be from venous, pial or arterial side?

PURPOSE

Dural arteriovenous fistula (DAVF) of the anterior cranial fossa with cortical venous reflux is an aggressive neurovascular entity with a high rate of intracranial bleeding. Only two cases of anterior cranial fossa DAVF presenting with epistaxis alone have been reported. Endovascular approaches have emerged as the primary and safer treatment modality for most DAVFs. Certain fistulas are better treated with open surgical approaches and disconnection.

CASE DESCRIPTION

A 55 years old male presented with the history of multiple episodes of severe epistaxis. Cerebral angiography revealed an anterior cranial fossa DAVF of the cribriform plate with cortical venous reflux and a venous varix. The patient was successfully managed with a bifrontal craniotomy and disconnection from the arterial side.

CONCLUSION

Atypical or severe epistaxis may arise from a DAVF. Surgical arterial disconnection my be a curative treatment option.

Lessons to Be Remembered from a Dural Arteriovenous Fistula Mimicking Medulla and High Cervical Cord Glioma

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

Incidental ethmoidal dural arteriovenous fistula coexisting with a pituitary adenoma exacerbating post-transsphenoidal epistaxis

A 64 year-old man with pituitary adenoma developed massive epistaxis after an uneventful endoscopic transsphenoidal surgery. Angiography showed extravasation from the sphenopalatine artery, to which embolisation was performed. An incidentally coexisting ethmoidal dural arteriovenous fistula supplied by the ophthalmic artery aberrantly originated from the middle meningeal artery caused increased haemorrhage.

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

BACKGROUND

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.

METHOD

Between 1999 and 2015, 14 patients with anterior cranial fossa DAVFs were submitted to surgery in two neurosurgical departments; the mean age was 63 years 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.

RESULTS

One patient died 5 days 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.

CONCLUSIONS

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.

Surgical management of cerebral dural arteriovenous fistulae

Dural arteriovenous fistulae are high flow, low resistance intracranial vascular malformations defined by an aberrant connection between an artery and dural vein or sinus. Symptomatology and presentation are highly dependent on location, generally categorized as supratentorial, tentorial, or infratentorial, and consist primarily of sequelae secondary to local venous hypertension, insufficiency, and cortical venous reflux. Surgery is generally reserved for high risk or persistently symptomatic lesions that are unamenable or unresponsive to endovascular therapy. For surgical lesions, familiarity with skull base approaches, specific fistula anatomy, and technical nuances based on fistula location offer patients the best chance of a favorable outcome.

Endovascular management of intracranial dural arteriovenous fistulas

Dural arteriovenous fistulas are a heterogeneous group of lesions that comprise 10-15% of intracranial vascular malformations. The treatment strategy is devised after careful consideration of the arterial supply, venous drainage, clinical presentation, and risk of progression, hemorrhage, or neurologic decline. With recent advancements in endovascular technology, the majority of dural arteriovenous fistulas can be treated with either transarterial or transvenous embolization. Those that cannot be fully treated by endovascular means are approached with either adjuvant surgery or radiotherapy.

Embryological Consideration of Dural Arteriovenous Fistulas

The topographical distribution of dural arteriovenous fistulas (DAVFs) was analyzed based on the embryological anatomy of the dural membrane. Sixty-six consecutive cases of intracranial and spinal DAVFs were analyzed based on the angiography, and each shunt point was identified according to the embryological bony structures. The area of dural membranes was categorized into three different groups: a ventral group located on the endochondral bone (VE group), a dorsal group located on the membranous bone (DM group) and a falco-tentorial group (FT group) located in the falx cerebri, tentorium cerebelli, falx cerebelli, and diaphragm sellae. The FT group was designated when the dural membrane was formed only with the dura propria (meningeal layer of the dura mater) and not from the endosteal dura. Cavernous sinus, sigmoid sinus, and anterior condylar confluence was categorized to VE group, which had a female predominance, more benign clinical presentations, and a lower rate of cortical and spinal venous reflux. Transverse sinus, confluence, and superior sagittal sinus belonged to the DM group. Olfactory groove, falx, tent of the cerebellum, and nerve sleeve of spinal cord were categorized to the FT group, which presented later in life and which had a male predominance, more aggressive clinical presentations, and significant cortical and spinal venous reflux. The DAVFs was associated with the layers of the dural membrane characterized by the two different embryological bony structures. The FT group was formed only with the dura propria as an independent risk factor for aggressive clinical course and hemorrhage of DAVFs.

Clinical and Anatomic Insights From a Series of Ethmoidal Dural Arteriovenous Fistulas at Barrow Neurological Institute

BACKGROUND

Ethmoidal dural arteriovenous fistulas (dAVFs) have a malignant natural history and an anatomy that make endovascular therapy challenging. Their uniqueness begs for stratified analyses, but this has largely been precluded by their rarity. We sought to summarize the anatomic, presentation, treatment approaches, and clinical outcomes of patients with these lesions.

METHODS

We reviewed our prospectively maintained institutional database to identify patients diagnosed with ethmoidal dAVFs from January 1, 2000, to December 31, 2015. We evaluated demographic, presentation, angiographic, treatment, and follow-up data.

RESULTS

In total, 27 patients with ethmoidal dAVFs underwent endovascular and/or surgical treatment. Mean patient age was 62 years old and there was a male sex predilection (67% men; 2:1 male-female ratio). All dAVFs exhibited direct cortical venous drainage; venous ectasia was present in 59% of cases. Of the dAVFs, 30% drained posteriorly into the basal vein of Rosenthal or the sylvian veins. Embolization with casting of the draining vein was successful in 2 of 9 cases (22%), including 1 successful transvenous case. There were no clinical or permanent complications from embolization; specifically, no patients experienced visual loss after treatment. Surgical treatment with successful dAVF obliteration was carried out in 24 of 24 patients (100%). One patient declined surgical treatment after attempted endovascular embolization. There were no permanent complications after surgical treatment and no cases of wound infection or cerebrospinal fluid leakage.

CONCLUSIONS

Surgical disconnection remains the gold standard in the treatment of ethmoidal dAVFs. Embolization is a consideration for well-selected cases with favorable arterial or venous access anatomy.

Dural Arteriovenous Fistulae: Imaging and Management

Intracranial dural arteriovenous fistulae (DAVF) are pathologic arteriovenous shunts between meningeal arteries and dural venous sinuses or veins. They account for approximately 10% to 15% of all intracranial vascular malformations and are most common in middle-aged patients. DAVF are the most common vascular cause of pulsatile tinnitus. Digital subtraction angiography remains the gold standard for diagnosing these lesions. The pattern of venous drainage determines the type of DAVF and their risk for hemorrhage. Endovascular treatment has become a first-line option for their management. This article describes the natural history, clinical presentation, classification, imaging features, and management options of intracranial DAVF.

Embryological Consideration of Dural AVF

BACKGROUND

The distribution of intracranial dural AVFs (DAVFs) may be affected by the embryological bony structures that consist of membranous bone and endochondral bone.

METHODS

We retrospectively analyzed the distribution of the shunt points in 58 consecutive cases of DAVFs. Shunt points were identified with selective digital subtraction angiography, high-resolution cone beam computed tomography (CT), or three-dimensional rotation angiography. All the shunt points were plotted on the map of the skull base in relation to the topography of the endochondral bone and the membranous bone. If the shunt point was localized on the surface of endochondral bone, this was categorized as the endochondral bone group. If it was located on membranous bone, this was categorized as the membranous bone group. If the shunt point was independent from both bony structures, this was categorized as the independent group.

FINDINGS

In 55 of 58 cases, shunt points were identified angiographically. Three cases had multiple shunts. There were 33 shunt points (60 %) belonging to endochondral bone. In this group, 16 cases of sigmoid, 11 of carotid cavernous, 3 of petrosal apex, and 3 of sigmoid DAVF were observed. There were 12 shunt points (22 %) localized on membranous bone; in this group, there were nine cases of transverse sinus, two of superior sagittal sinus, and one case of confluence DAVF. There were ten shunt points (18 %) independent from these two bony structures: four cases of olfactory groove, four . of middle fossa, and two of hypoglossal canal DAVF.

CONCLUSIONS

There were correlations between the localization of shunt points of DAVFs and the topography of endochondral bone and the membranous bone. The histological difference of endochondral bone and membranous bone at the level of epidural space might cause the formation of DAVFs.

An Unusual Case of an Ethmoidal Arteriovenous Fistula Draining Into the Superior Ophthalmic Vein: Technical Case Report

BACKGROUND AND IMPORTANCE

Ethmoidal arteriovenous fistulae (AVF) are uncommon and are characterized by an aggressive clinical course. Typical venous drainage is into the frontal cortical veins. We present the case of a 76-year-old male patient who was found to have a right ethmoidal AVF draining directly into the superior ophthalmic vein (SOV), with no cavernous sinus involvement and an associated SOV aneurysm and was successfully treated using surgical cutdown of the SOV followed by endovascular embolization.

CLINICAL PRESENTATION

A 76-year-old man presented with chemosis, proptosis, and lid lag with occasional diplopia. Based on the clinical presentation, there was a suspicion of a carotid cavernous fistula. Cerebral angiography demonstrated a right ethmoidal to SOV fistula, without any involvement of the cavernous sinus, and a SOV aneurysm. Transarterial embolization of the fistula was attempted but was unsuccessful. An SOV approach was performed using SOV cutdown followed by endovascular embolization of the fistula from a transocular route using coils and Onyx embolic agent. There was complete obliteration of the fistula and associated venous aneurysm. The patient had a remarkable recovery.

CONCLUSION

In rare cases, ethmoidal AVFs can present with an unusual venous drainage. Clinical presentation may be similar to carotid cavernous fistulae, and proper identification of the lesion using an angiogram is essential to guide treatment. In cases in which other approaches fail to treat the fistula, direct surgical exposure of the SOV followed by embolization using coiling and Onyx may be successful in achieving AVF occlusion.

Visual Field Defect after Transfrontal Sinus Approach of Ethmoidal Dural Arteriovenous Fistulas (eDAVFs) : Experience and Complication of Transfrontal Sinus Approach

The approach to ethmoidal dural arteriovenous fistulas (eDAVFs) is usually via a pterional or a frontal craniotomy. However, the transfrontal sinus is a more direct route to the fistula. The aim of this report is to describe our experience and associated complications occurring as a result of flow diversion in the transfrontal sinus approach for eDAVFs. In this report, we discuss visual field defects occurring after a transfrontal sinus operation. This approach is most direct for surgical treatment of an eDAVF, enabling preservation of neural structures with minimal to no negative effects on the brain. Although the surgery was uneventful, the patient presented with a left side visual field defect. An ophthalmologic exam detected an arterial filling delay in the choroidal membrane and ischemic optic neuropathy was highly suspected. The patient is currently recovering under close observation with no special treatment. The transfrontal sinus approach provides the most direct and shortest route for eDAVFs, while minimizing intraoperative bleeding. However, complications, such as visual field defects may result from a sudden flow diversion or eyeball compression due to scalp traction.

Endovascular treatment of cribriform plate dural arteriovenous fistulas: technical difficulties and complications avoidance

OBJECTIVE

Cribriform plate dural arteriovenous fistula (dAVF) is a rare pathology, for which the treatment of choice used to be neurosurgery. Technological advances in micro-catheters and embolic agents permitted new endovascular alternatives.

METHODS

We included all patients treated endovascularly for a cribriform plate dAVF between 2008 and 2013. We retrospectively analysed data focusing on the type of treatment chosen.

RESULTS

Ten patients were treated by endovascular approach, with a need for an additional surgical exclusion of the fistula in two cases. Thirteen embolisation sessions were done. Embolisation of the fistula through an ethmoidal artery was the technique of choice; the catheterism of the ophthalmic artery was impossible in two cases and the embolic agent did not penetrate in four cases. The embolisation through the middle meningeal artery was successful in one case but the tortuosity of this artery prevented good penetration of the embolic agent. Venous approach was successful in all cases but was limited to fistulas with superficial venous drainage.

CONCLUSIONS

Endovascular treatment of cribriform plate dAVF is safe and effective. The embolisation through ethmoidal artery is the method of choice. Branches of the middle meningeal artery are tortuous and prevent the penetration of embolic agent. Venous approach is effective but is limited to cases of failure of the arterial approach.