Treatment of dural arteriovenous fistula using ethylene vinyl alcohol (onyx) arterial embolization as the primary modality: short-term results

Onyx as an adjunctive embolic material for transvenous embolization of cavernous sinus dural arteriovenous fistula after coiling

BACKGROUND

Transvenous coil embolization (TVCE) is a common and effective treatment for cavernous sinus dural arteriovenous fistulas (CSDAVFs). However, some patients may experience residual fistulas or worsening visual symptoms after the procedure. This study aimed to compare the effectiveness of transvenous coil and Onyx embolization (TVCOE) with TVCE in treating CSDAVFs.

METHODS

The study included 207 patients with 222 CSDAVFs referred for TVCE, all of whom had complete angiographic follow-up over 9 years. Ninety patients (mean age, 65.3 years) with 97 CSDAVFs underwent TVCOE after coiling. Clinical data, angioarchitecture, and outcomes were retrospectively assessed and compared to 125 CSDAVFs treated with TVCE.

RESULTS

Key reasons for selecting TVCOE included improvement in immediate complete obliteration of CSDAVFs (n = 47, 48.5%), presence of cranial nerve palsy (n = 26, 26.8%), residual fistula with persistent pial venous reflux (n = 22, 22.7%), and redirection of fistula flow to pial venous reflux (n = 2, 2.1%). The average volume of Onyx used in TVCOE was 1.7 mL per CSDAVF. The mean coil lengths for TVCOE and TVCE were 143 and 228 cm, respectively, with a statistically significant difference ( p < 0.05). Immediate digital subtraction angiography showed complete obliteration or nearly complete obliteration of CSDAVFs in TVCOE and TVCE at rates of 97.9% and 76.8%, respectively, indicating statistical significance in immediate complete obliteration ( p < 0.05). Transient hemodynamic instability occurred in 81 (90.0%) patients due to Onyx toxicity, and one patient (1.1%) experienced hemorrhagic complications during TVCOE.

CONCLUSION

The use of a small volume of Onyx as an adjunctive embolic material in TVCOE resulted in reduced coil use and improved immediate complete obliteration. This technique is viable for patients with pial venous reflux. Aside from the transient hemodynamic instability, periprocedural complications and follow-up angiographic outcomes did not show significant differences between the two groups.

Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas Cognard Type V With Direct Drainage Into the Perimedullary Veins: Case Report and Literature Review

BACKGROUND AND IMPORTANCE

Cognard type V fistula (CVF) is a rare type of dural arteriovenous fistula characterized by spinal perimedullary venous drainage. Owing to the lack of pathognomonic findings, misdiagnosis is common. Patients often undergo multiple spinal angiograms negative for spinal vascular malformations. Digital subtraction angiography is the gold standard diagnostic tool. The preferred treatment option is endovascular management with embolization through a transarterial, transvenous, or combined approach. Other options include open surgery, stereotactic radiosurgery, or a combination of both.

CLINICAL PRESENTATION

The patient from case # 1 presented with progressive weakness and hypoesthesia in the bilateral lower extremities, with urinary and bowel incontinence. The DSA identified a CVF fed by the meningohypophyseal trunk and a draining perimedullary vein. Embolization with 0.1 ccs of Onyx-18 was performed with complete fistula occlusion. The patient from case # 2 developed bilateral lower extremity weakness, diffuse numbness, and urinary incontinence. The DSA showed a CVF fed by tributaries from the ascending pharyngeal artery and posterior meningeal artery branches of the V3 segment, draining into a perimedullary vein. Embolization with 0.3 cc of Onyx-18 was performed with 100% occlusion of the fistula. A 1-year follow-up angiogram confirmed complete fistula occlusion. Both patients consented to the procedure.

CONCLUSION

Even if a patient only presents symptoms of myelopathy, CVF should be considered. Herein, we present 2 cases of CVF with direct drainage into the perimedullary veins which presented exclusively with myelopathy syndrome and describe treatment with trasarterial embolization with Onyx.

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.

Combined transarterial and transvenous embolization of anterior cranial fossa dural arteriovenous fistula

Background

Excessive glue injection into the drainage vein in patients with dural arteriovenous fistula (dAVF) can result in venous obstruction. We performed transarterial embolization (TAE) combined with transvenous embolization (TVE) with coils to prevent the glue from migrating into the normal cortical veins.

Case Description

A 57-year-old man was pointed out to have a Borden Type III anterior cranial fossa dAVF during a check-up for putaminal hemorrhage. Because a left frontal normal cortical vein drained into the pathological drainage vein, excessive glue injection into the drainage vein may have caused venous obstruction. We performed TVE with coils at the foot of the draining vein to prevent excessive migration of glue into the drainer, followed by TAE with glue. With this technique, complete obliteration of the shunt without venous ischemia was obtained.

Conclusion

The combined treatment of TAE and TVE is effective in preventing venous ischemia caused by unintended migration of glue cast into the drainage vein.

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

Objective

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

Case Presentation

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

Conclusion

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

Long-term stability of Onyx: is there any indication for repeated angiography after dural arteriovenous fistula embolization?

OBJECTIVE

The natural course of dural arteriovenous fistulas (DAVFs) is unfavorable. Transarterial embolization with Onyx is currently the therapeutic method of choice, although the long-term stability of Onyx has been questioned. The literature reports a significant difference in the recurrence rate after complete DAVF occlusion and lacks larger series with long-term follow-up. The authors present the largest series to date with a long-term follow-up to determine the stability of Onyx, prospectively comparing magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) as follow-up diagnostic methods.

METHODS

Demographics, clinical symptomatology, length of follow-up, diagnostic methods, and angiographic findings of DAVFs were recorded and retrospectively evaluated in 112 patients. A prospective group of 15 patients with more than 5 years of follow-up after complete DAVF occlusion was established. All 15 patients in the prospective group underwent a clinical examination and MRA; 10 of these patients also underwent DSA. The recurrences and the correlation between the two diagnostic methods were evaluated.

RESULTS

Among the 112 patients, 71 were men and 41 were women, with an average age of 60 years. Intracranial hemorrhage (40%) was the most common clinical presentation of DAVF. At the last follow-up, 73% of the patients experienced clinical improvement, 21% remained unchanged, and 6% worsened. Overall, 87.5% of the DAVFs were occluded entirely with endovascular treatment, and 93% of the DAVFs were classified as cured at the last follow-up (i.e., completely embolized DAVFs and DAVFs that thrombosed spontaneously or after Gamma Knife surgery). Two recurrences of DAVFs were recorded in the entire series. Both were first diagnosed by MRA and confirmed with DSA. The mean follow-up was 27.7 months. In the prospective group, a small asymptomatic recurrence was diagnosed. The mean follow-up of the prospective group was 96 months.

CONCLUSIONS

Onyx is a stable embolic material, although recurrence of seemingly completely occluded DAVFs may develop because of postembolization hemodynamic changes that accentuate primarily graphically absent residual fistula. These residuals can be diagnosed with MRA at follow-up. The authors' data suggest that MRA could be sufficient as the follow-up diagnostic method after complete DAVF occlusion with Onyx. However, larger prospective studies on this topic are needed.

Onyx embolization for dural arteriovenous fistulas: a multi-institutional study

BACKGROUND

Although the liquid embolic agent, Onyx, is often the preferred embolic treatment for cerebral dural arteriovenous fistulas (DAVFs), there have only been a limited number of single-center studies to evaluate its performance.

OBJECTIVE

To carry out a multicenter study to determine the predictors of complications, obliteration, and functional outcomes associated with primary Onyx embolization of DAVFs.

METHODS

From the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR) database, we identified patients who were treated for DAVF with Onyx-only embolization as the primary treatment between 2000 and 2013. Obliteration rate after initial embolization was determined based on the final angiographic run. Factors predictive of complete obliteration, complications, and functional independence were evaluated with multivariate logistic regression models.

RESULTS

A total 146 patients with DAVFs were primarily embolized with Onyx. Mean follow-up was 29 months (range 0-129 months). Complete obliteration was achieved in 80 (55%) patients after initial embolization. Major cerebral complications occurred in six patients (4.1%). At last follow-up, 84% patients were functionally independent. Presence of flow symptoms, age over 65, presence of an occipital artery feeder, and preprocedural home anticoagulation use were predictive of non-obliteration. The transverse-sigmoid sinus junction location was associated with fewer complications, whereas the tentorial location was predictive of poor functional outcomes.

CONCLUSIONS

In this multicenter study, we report satisfactory performance of Onyx as a primary DAVF embolic agent. The tentorium remains a more challenging location for DAVF embolization, whereas DAVFs located at the transverse-sigmoid sinus junction are associated with fewer complications.

Treatment of Recurrent Aneurysm of the Internal Carotid Artery-poster Communicating Artery Using the Marathon Microcatheter: A Case Report

Objective

We report the case of an aneurysm of the recurrent internal carotid artery (ICA)-posterior communicating artery (PCoA) treated using a liquid embolic delivery microcatheter (MC; Marathon).

Case Presentation

A 66-year-old female previously presented with subarachnoid hemorrhage, which had been treated using coil embolization for a ruptured ICA-PCoA aneurysm. She was referred to our hospital because the aneurysm recurred 13 years after treatment. Angiography revealed a de novo lobulated aneurysm at the ICA-PCoA bifurcation with a relatively thickened PCoA branching from the neck of the aneurysm. We performed coil embolization after stent placement with the Neuroform Atlas in the range of the ICA terminus and the PCoA. However, the coils were unequally distributed and it was necessary to navigate the MC to the aneurysm within the stent through the PCoA. We successfully approached the aneurysm using the Marathon. We additionally inserted six ED coils into the aneurysm and achieved favorable embolization.

Conclusion

The Marathon is useful for passage of a stent deployed in a small-caliber artery.

Delayed Fragmentation and Distal Embolization of Retained Microcatheter Causing Lower Limb Ischemia: Case Report and Review of the Literature

BACKGROUND

Endovascular microcatheter adherence and retention is an uncommon complication during brain arteriovenous malformation (AVM) embolization with glue or ethylene-vinyl alcohol copolymer that has previously reported, although there are sparse reports of symptomatic complications thereafter.

CASE DESCRIPTION

We present a unique complication 6 years after initial embolization of a cerebral AVM. The patient presented with acute lower limb insufficiency with computed tomography angiogram revealing fragmentation of the microcatheter and associated popliteal aneurysm. The patient underwent an emergency grafting and removal of the retained fragment and recovered without deficit postoperatively.

CONCLUSIONS

Fragmentation over retained microcatheters remains a concern that may be worth monitoring in the long term, although there are no recommendations for timing.

Endovascular treatment of the cavernous sinus dural arteriovenous fistula: current status and considerations

A cavernous sinus dural arteriovenous fistula (CS-DAVF) is an abnormal arteriovenous communication involving the dura mater within or near the CS wall. The dural arteries from the internal carotid artery and external carotid artery supply the CS-DAVF, and the superior ophthalmic vein (SOV) and inferior petrous sinus (IPS) are frequent venous drainers. In CS-DAVF cases, high-risk lesions require treatment. Endovascular treatment (EVT) has been the first-line option for CS-DAVFs. To our knowledge, a review of the EVT of CS-DAVFs is lacking. Therefore, in this paper, we review the available literature on this issue. In addition, some illustrative cases are also provided to more concisely expound the EVT of CS-DAVFs. According to the recent literature, transvenous embolization via the IPS is considered the most effective method for EVT of CS-DAVFs. In addition, the transorbital approach is another reasonable choice. Other venous approaches can also be tried. Because of the low cure rate, transarterial embolization for CS-DAVFs is limited to only highly selected patients. In the EVT of CS-DAVFs, various agents have been used, including coil, Onyx, and n-butyl cyanoacrylate, with coil being the preferred one. In addition, when EVT cannot obliterate the CS-DAVF, stereotactic radiotherapy may be considered. In general, despite various complications, EVT is a feasible and effective method to manage CS-DAVFs by way of various access routes and can yield a good prognosis.

Successfully disposal of an acute MCA occlusion by Onyx during AVM embolism

Purpose: To report a rare complication that Onyx gel blocked the MCA trunk and branches unexpectedly during AVM embolism and our strategy to rescue. Material and methods: A 16 years old otherwise healthy girl hold a left side Spetzler - Martin grade III fronto-temporal AVM, during embolization, the L-MCA and its branches were blocked by Onyx completely, the patient was transferred to the operating room to extract the Onyx gel immediately. Result: After totally 10 arterotomies, all the Onyx gel were removed. 8 hours after occlusion, all arteries were then seen to pulsate. Conclusion: Iatrogenic MCA full-length acute occlusion is a rare and severe complication during AVM embolism. Carefully identify the feeding arteries, micro-catheter angiography before Onyx gel injection and balloon-assisted embolism could probably prevent it. Surgical operation to extract onyx gel and re-canalize MCA was recommended, AVM should be resect if possible.

Coil-Protected Technique for Liquid Embolization in Neurovascular Malformations

OBJECTIVE

To evaluate the safety and efficacy of the coil-protected technique for liquid embolization in neurovascular malformations.

MATERIALS AND METHODS

Twenty-two patients who underwent coil-protected liquid embolization for symptomatic cranial (n = 13) and spinal (n = 9) arteriovenous fistula (AVF) or arteriovenous malformations (AVMs) were identified. A total of 36 target feeder vessels were embolized with N-butyl cyanoacrylate and/or Onyx (Medtronic). This technique was used to promote delivery of a sufficient amount of liquid embolic agent into the target shunt or nidus in cases where tortuous feeding arteries preclude a microcatheter wedging techniqu and/or to prevent reflux of the liquid embolic agent in cases with a short safety margin. The procedure was considered technically successful if the target lesion was sufficiently filled with liquid embolic agent without unintentional reflux. Angiographic and clinical outcomes were retrospectively evaluated.

RESULTS

Technical success was achieved for all 36 target feeders. Post-embolization angiographies revealed complete occlusion in 16 patients and near-complete and partial occlusion in three patients each. There were no treatment-related complications. Of the six patients who showed near-complete or partial occlusion, five received additional treatments: two received stereotactic radiosurgery for cerebral AVM, two underwent surgical removal of cerebral AVM, and one underwent additional embolization by direct puncture for a mandibular AVM. Finally, all patients showed complete (n = 19) or near-complete (n = 3) occlusion of the target AVF or AVM on follow-up angiographies. The presenting neurological symptoms improved completely in 15 patients (68.2%) and partially in seven patients (31.8%).

CONCLUSION

The coil-protected technique is a safe and effective method for liquid embolization, especially in patients with various neurovascular shunts or malformations who could not be successfully treated with conventional techniques.

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.

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.

Onyx versus nBCA and coils in the treatment of intracranial dural arteriovenous fistulas

BACKGROUND AND PURPOSE

Intracranial dural arteriovenous fistulas (DAVFs) with cortical venous drainage have significant morbidity and mortality. Complete closure of these lesions is necessary to reduce these risks. The purpose of our study was to compare the outcome of DAVFs treated with Onyx versus those treated with n-Butyl Cyanoacrylate (nBCA) and coil embolization in a case-control study. Compared with nBCA and coil embolization, we hypothesized that Onyx embolization for DAVF is safer and has a higher chance of complete obliteration, with no need for post-embolization surgery for the DAVF.

MATERIALS AND METHODS

From 1998 to 2015, 29 patients who had DAVFs were treated with endovascular embolization. Of these, 24 patients had imaging available for analysis. Successful closure rates, complications, and procedure time were compared between the embolization techniques.

RESULTS

The chance of not requiring post-embolization surgery with Onyx (81.8%) was significantly higher (p = 0.005) than with nBCA (22.22%). The complication rate with Onyx (9.1%) tended to be lower compared with that of nBCA (22.22%; p = 0.37). Procedural time was not significantly different between Onyx (mean 267 minutes) and nBCA (mean 288 minutes) (p = 0.59). The odds ratio of a DAVF being treated with Onyx and then requiring no follow-up surgery was 17.5 (95% CI 1.97-155.4).

CONCLUSION

Our case-control study suggests that Onyx embolization is superior to nBCA and coil embolization in completely obliterating DAVFs, with higher odds of no post-embolization surgery. We also found that Onyx is safe for embolization of DAVFs, with no associated neurological mortality and morbidity.

Spinal Dural Arteriovenous Fistula: Imaging Features and Its Mimics

Spinal dural arteriovenous fistula (SDAVF) is the most common spinal vascular malformation, however it is still rare and underdiagnosed. Magnetic resonance imaging findings such as spinal cord edema and dilated and tortuous perimedullary veins play a pivotal role in the confirmation of the diagnosis. However, spinal angiography remains the gold standard in the diagnosis of SDAVF. Classic angiographic findings of SDAVF are early filling of radicular veins, delayed venous return, and an extensive network of dilated perimedullary venous plexus. A series of angiograms of SDAVF at different locations along the spinal column, and mimics of serpentine perimedullary venous plexus on MR images, are demonstrated. Thorough knowledge of SDAVF aids correct diagnosis and prevents irreversible complications.

Arterial Onyx Embolisation of Intracranial DAVFs with Cortical Venous Drainage

Purpose:

To present our experience with the endovascular management of intracranial dural arteriovenous fistulas with direct cortical venous drainage by trans-arterial embolisation using Onyx.

Materials & Methods:

Between January 2004 and April 2008, 12 consecutive high grade intracranial dural arteriovenous fistulas (Cognard type III (eight patients) or IV (three patients)) were treated by trans-arterial embolisation with Onyx. The majority of cases were treated by Onyx embolisation alone. One case had additional embolisation with n-butyl-2-cyanoacrylate at the same session. Imaging follow-up was obtained in all but one patient (mean 3.6 months).

Results:

Nine patients had a technical success at the end of the embolisation procedure with complete angiographic exclusion of the fistula. Two patients had a small residual fistula at the end of embolisation, one of which had residual mild cortical venous drainage. Both were stable at follow-up angiography. One patient had a residual fistula supplied by the ophthalmic artery, which was thought to be unsafe to embolise and was sent for surgery, which was curative. In one patient the microcatheter ruptured, with a fragment of the distal microcatheter left in the occipital artery. No clinical complications were observed in this series at clinical follow-up (mean 3.3 months). Two patients were noted to have significant radiation dose.

Conclusion:

Endovascular management of intracranial dural arteriovenous fistulas with direct venous cortical drainage by trans-arterial Onyx embolisation is a safe and effective treatment according to our experience. Fluoroscopy times and radiation dose may be a concern.

Issues in the diagnosis and management of the papilledema shunt

BACKGROUND

Dural arteriovenous fistulas (DAVFs) that shunt blood into the transverse or superior sagittal venous sinuses cause papilledema by raising intracranial pressure ("the papilledema shunt"). Such fistulas pose unique diagnostic and therapeutic challenges.

METHODS

Case report and literature review.

RESULTS

In a patient presenting with papilledema, non-invasive brain vascular imaging disclosed subtle signs of a DAVF. Digital angiography delineated the DAVF and revealed cortical venous reflux. After three transarterial embolizations with ethylene vinyl alcohol, the DAVF was closed and papilledema resolved.

CONCLUSIONS

The imaging features of a DAVF that cause papilledema may be subtle on non-invasive vascular imaging. If overlooked, and lumbar puncture is performed, there is a substantial risk of brain herniation. Cortical venous reflux, which may be relatively common in these DAVFs, impels the need for endovascular closure. The transvenous route, often employed for closing cavernous sinus DAVFs, should be avoided because of the dangers of dural venous sinus thrombosis.

The usefulness of subcutaneous infiltration of epinephrine-containing lidocaine for curative transarterial embolization of dural arteriovenous fistula. A technical note

Recently, transarterial embolization (TAE) with liquid embolic materials has been recognized as one of the curative therapeutic options for non-sinus type dural arteriovenous fistula (d-AVF). To prevent glue fragmentation and incomplete obliteration, flow reduction of transosseous high-flow feeders is one of the key points of this therapy. However, flow reduction of transosseous feeders is sometimes difficult with previously reported techniques such as particle embolization, manual compression, or proximal balloon occlusion. This report introduces a new technique to reduce the flow of transosseous feeders using epinephrine-containing lidocaine, and describes a case of intracranial d-AVF successfully treated with this technique. The usefulness and efficacy of the technique are discussed.

Embolization of spinal dural arteriovenous fistula via the retrocorporeal artery: case report

BACKGROUND AND IMPORTANCE

The goal of spinal dural arteriovenous fistula (DAVF) treatment is to permanently occlude the proximal draining vein and the fistula itself, which can be achieved by open surgery or endovascular treatment. The endovascular approach is currently the primary treatment, but it requires the presence of an access as close to the site of the fistula as possible. This case illustrates that the retrocorporeal artery may be an alternative option in case of previous embolization failure with proximal occlusion of the radicular arteries.

CLINICAL PRESENTATION

A 54-year-old man presented with an 18-month history of progressive paraparesis secondary to right L2 spinal DAVF. The first endovascular treatment failed to achieve occlusion of the fistula via the ipsilateral L2 and L3 radicular arteries. Given the proximal occlusion of these feeders during the first embolization, the dilated retrocorporeal arteries were approached via the contralateral L2 and L3 radicular arteries. Complete occlusion of the fistula was achieved with Onyx in a single session with progressive improvement of preoperative neurological deficit.

CONCLUSION

The retrocorporeal artery may provide a safe alternative approach to spinal DAVFs in cases in which a conventional endovascular approach failed, thus avoiding invasive surgical treatment.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Safety of retained microcatheters: an evaluation of radiofrequency heating in endovascular microcatheters with nitinol, tungsten, and polyetheretherketone braiding at 1.5 T and 3 T

BACKGROUND

The use of ethylene-vinyl alcohol copolymer for liquid embolization of cranial vascular lesions has resulted in microcatheter fragments entrapped in patients following endovascular procedures. Undergoing subsequent diagnostic MRI examinations poses a safety concern due to the possibility of radiofrequency heating of the metallic braid incorporated into the microcatheter. Heating of nitinol, tungsten, and polyetheretherketone (PEEK) braided microcatheters was assessed and compared using a phantom model.

METHODS

Microcatheters coupled with fluoroptic temperature probes were embedded in a polyacrylamide gel within a head and torso phantom. Experiments were performed at 1.5 T and 3 T, analyzing the effects of different catheter immersion lengths, specific absorption rate (SAR) levels, short clinical scans, long clinical scans, and microcatheter fragment lengths.

RESULTS

The maximal increase in temperature for the nitinol braided microcatheter during a 15 min scan was 3.06°C using the T1 fast spin echo sequence at 1.5 T and 0.45°C using the balanced steady state free precession sequence at 3 T. The same scans for fragment lengths of 9, 18, 36, and 72 cm produced maximal temperature rises of 0.68, 0.80, 1.70, and 1.07°C at 1.5 T, respectively. The temperature changes at 3 T for these fragment lengths were 0.66, 0.83, 1.07, and 0.72°C, respectively. The tungsten and PEEK braided microcatheters did not demonstrate heating.

CONCLUSIONS

Substantial heating of nitinol braided microcatheters occurred and was a function of SAR level and geometric considerations. SAR and time limitations on MR scanning are proposed for patients with this microcatheter entrapped in their vasculature. In contrast, tungsten and PEEK braided microcatheters showed potential safe use in MRI.

Percutaneous treatment of subarachnoid-pleural fistula with Onyx

Subarachnoid-pleural fistula is a well-described complication after anterior surgery for thoracic disc herniation, but is difficult to treat by means of traditional chest and lumbar drains due to interference by positive ventilation pressures that may keep the fistula open and prevent proper closure. Current treatment strategies include surgical repair, which is technically challenging, and noninvasive positive pressure ventilation, which can take several weeks to be effective. In this report, the authors describe a novel treatment for subarachnoid-pleural fistula using percutaneous obliteration with Onyx.

Surgery for removal of a T7–8 disc herniation associated with ossification of the posterior longitudinal ligament was performed in a 56-year-old woman via an anterior transthoracic transpleural approach. Ten days after surgery, she presented with diplopia due to a subarachnoid-pleural fistula that was confirmed by CT myelography. Percutaneous injection of Onyx was performed under local anesthesia. Postprocedure CT showed complete obliteration of the fistula with no adverse events. A CT scan obtained 1 month later showed complete resolution of the pleural effusion. Neurological examination at 3 months postsurgery was normal. Clinical and radiological follow-up at 1 year showed complete recovery and no sign of fistula recurrence. Percutaneous treatment for subarachnoid-pleural fistula is an easy, safe, and effective strategy and can therefore be proposed as a first-line option for this challenging complication.

Surgical management of dural arteriovenous fistulas of the transverse-sigmoid sinus in 42 patients

A retrospective study was performed to analyse a prospectively collected database from a single surgeon (M.K.M.) of transverse-sigmoid sinus dural arteriovenous fistulas (DAVF) between 1991 and August 2011. During the study period, 144 patients with 160 DAVF were managed. Sixty-five of the DAVF were located in the transverse-sigmoid sinus and 42 were treated with surgery, or embolisation and surgery. All patients who underwent surgery were symptomatic with retrograde cortical venous drainage. The average follow-up period was 18months (range, 2-82months). Total elimination of the DAVF was achieved in all instances, including two patients (5%) who required further surgery after postoperative cerebral angiography showed that some venous drainage had persisted after the first operation. There was no new permanent neurological deficit or mortality attributable to surgery. Our institutional experience shows that in selected patients with transverse-sigmoid sinus DAVF, the involved sinus can be surgically resected with a high success rate and it is as safe as many alternative options. We suggest that this definitive treatment option should be offered to patients, and the outcome should be compared to other treatment modalities.

Continued Concern About Parent Vessel Steno-Occlusive Progression With Onyx HD-500 and the Utility of Quantitative Magnetic Resonance Imaging in Serial Assessment

BACKGROUND:

Onyx HD-500 is a liquid embolic used to treat intracranial aneurysms.

OBJECTIVE:

To determine the incidence of parent vessel stenosis and the management strategy for these patients.

METHODS:

Medical records of patients treated with Onyx HD-500 between 2008 and 2011 were retrospectively reviewed. Clinical and radiographic evaluations were assessed. Quantitative magnetic resonance angiography and NOVA (VasSol, Chicago, Illinois) images were reviewed for patients in whom these examinations were acquired.

RESULTS:

Seventeen patients underwent treatment of unruptured internal carotid artery aneurysms. Three patients (17.6%) developed visual symptoms after the procedure: 2 permanent and 1 transient. Four patients (23.5%) developed delayed internal carotid artery stenosis at the 6- to 8-month follow-up angiography, despite a standard antiplatelet regimen with confirmed sensitivities to aspirin and clopidogrel. Quantitative magnetic resonance angiography was obtained in all patients with stenosis to guide treatment. One patient progressed to complete but asymptomatic internal carotid artery occlusion. The second and third patients had asymptomatic stenosis of 40% and 70%, respectively, both of which resolved on follow-up angiography. The fourth patient developed critical stenosis distal to the aneurysm neck. Quantitative magnetic resonance angiography demonstrated adequate flow in the first 3 patients and decreased flow in the fourth patient, necessitating angioplasty and stenting. Prolonged dual antiplatelet regimens were continued in 2 of the 4 patients, 1 with progression of stenosis and 1 with improvement of stenosis.

CONCLUSION:

We observed a higher rate of parent vessel steno-occlusive progression after aneurysm embolization with Onyx HD-500 than reported in the literature, despite overall low morbidity. Quantitative vessel flow imaging was useful in subsequent medical management and decision making to perform therapeutic angioplasty/stenting to preserve flow.

Recurrence of "cured" dural arteriovenous fistulas after Onyx embolization

Endovascular embolization with Onyx has been increasingly used to treat intracranial and spinal dural arteriovenous fistulas (DAVFs). Several case series have been published in recent years reporting high DAVF cure rates with this technique. Although it is seldom reported, DAVF recurrence may occur despite initial "cure." The authors present 3 separate cases of a recurrent DAVF after successful transarterial Onyx embolization. Despite adequate Onyx penetration into the fistula and draining vein, these cases demonstrate that DAVF recanalization may reappear with filling from previous or newly recruited arterial feeders. Other published reports of DAVF recurrence are examined, and potential contributory factors are discussed. These cases highlight the need for awareness of this possible phenomenon and suggest that follow-up angiography should be considered in patients treated with catheter embolization.

WITHDRAWN: Onyx embolization of high flow spontaneous cervical vertebral arteriovenous fistula

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Onyx embolization of high-flow spontaneous cervical vertebral arteriovenous fistula

BACKGROUND AND IMPORTANCE

High-flow spontaneous vertebral arteriovenous shunts in patients with fibromuscular disease (FMD) are rare. Onyx embolization of the recipient veins with shunt disconnection and preservation of the affected vertebral artery in a patient with FMD has not been reported.

CLINICAL PRESENTATION

A 59-year-old female presented with progressive dizziness, pre-syncopal episodes, and tinnitus. Catheter-based angiography identified features of fibromuscular dysplasia and a high-flow right cervical vertebral artery arteriovenous shunt. Onyx embolization of the principle draining veins was performed with initial detachable coil placement. Complete disconnection of the shunt was achieved without sacrifice of the parent vertebral artery.

CONCLUSION

Spontaneous high-flow vertebral arteriovenous shunts can be successfully occluded with Onyx/detachable coil embolization of the principle recipient veins.

Pontine venous congestion due to dural arteriovenous fistula of the cavernous sinus: Case report and review of the literature

Background:

We report herein a case of cavernous sinus (CS)-dural arteriovenous fistula (DAVF) with brainstem venous congestion that was successfully treated by transarterial embolization, followed by radiotherapy.

Case Description:

An 80-year-old woman presented with right eye chemosis and left hemiparesis. T2-weighted magnetic resonance imaging showed hyperintensity of the pons. Diagnostic cerebral angiography demonstrated CS-DAVF draining into the right superior orbital vein and petrosal vein, and fed by bilateral internal and external carotid arteries. Transarterial embolization was performed and followed by radiotherapy, resulting in resolution of the pontine lesion and neurological and ophthalmological symptoms within 5 months.

Conclusions:

We also review the literature regarding therapy for CS-DAVF with brainstem venous congestion. Once CS-DAVF with venous congestion of the brainstem has been definitively diagnosed, immediate therapy is warranted. Treatment with transarterial embolization followed by radiation may be an important option for elderly patients when transvenous or transarterial embolization is not an option.

Vascular disorders--magnetic resonance angiography: brain vessels

Magnetic resonance angiography (MRA) of the brain obtained at 3 T imaging has made a significant clinical impact. MRA benefits from acquisition at higher magnetic field strength because of higher available signal-to-noise ratio and improved relative background suppression due to magnetic field strength-related T1 lengthening. Parallel imaging techniques are ideally suited for high-field MRA. Many of the developments that have made 3 T MRA of the brain successful can be regarded as enabling technologies that are essential for further development of 7 T MRA, which brings additional challenges.

Endovascular treatment of tentorial dural arteriovenous fistulae

Tentorial dural arteriovenous fistula (DAVF) is a rare vascular disease, which accounts for less than 4% of all cases of intracranial DAVF. Because of the high risk of intracranial hemorrhage, patients with tentorial DAVF need aggressive treatment. Management approaches are still controversial, and endovascular treatment has emerged as an effective alternative. In the current work, we describe our experience with the endovascular approach in the treatment of these deep and complex DAVF of the tentorium. Eight patients were treated between January 2006 and July 2009. Six patients (75%) presented with intracranial hemorrhage related to the DAVF rupture. Four patients (50%) had subarachnoid bleeding and two had intraparenchymal hematoma. Endovascular treatment was performed via the transarterial route alone in five cases (62.5%), by the transvenous approach in two cases (25.0%) and in a combined procedure using both arterial and venous routes in one patient (12.5%). Complete obliteration of the fistula was achieved in all cases. The outcome at 15 months was favorable (modified Rankin scale 0-3) in seven (87.5%) patients. Complete cure of the lesion was confirmed in these cases. This paper reports on the effectiveness of endovascular treatment in tentorial DAVF management. The choice of the venous versus the arterial approach is determined by regarding different anatomical dispositions.

Transarterial treatment with Onyx of intracranial dural arteriovenous fistula with cortical drainage in 17 patients

BACKGROUND AND PURPOSE

Intracranial DAVFs with cortical venous drainage have a high tendency to bleed. Complete closure of these lesions is essential to prevent clinically deleterious events. We describe our experience using Onyx in an arterial approach for treatment of DAVFs in 17 patients.

MATERIALS AND METHODS

Between 2006 and 2010, we used Onyx for performing transarterial embolization in 17 patients with intracranial DAVFs and cortical venous drainage. Clinical assessment was performed before and after every treatment at discharge and at follow-up. Fourteen patients underwent follow-up MR imaging and MRA, 8 of them also underwent follow-up diagnostic angiography.

RESULTS

Fifteen patients (88%) underwent 1 procedure. Complete obliteration by embolization with Onyx was achieved in 16 patients (94% acute obliteration). The mean amount of Onyx injected was 2.3 mL (range, 0.4-4.8 mL). The sole technical complication was an embolus to a branch of the MCA, which was resolved by intra-arterial tPA injection. A clinical complication of transient trochlear nerve palsy in the same patient due to mass effect of Onyx resolved spontaneously within 3 months.

CONCLUSIONS

Intra-arterial embolization of cranial DAVFs with cortical venous drainage by using Onyx results in a high rate of complete obliteration (94%) with low morbidity (6%). Follow-up DSA in 8 patients revealed no evidence of reopening.

A case of intraosseous dural arteriovenous fistulas involving diploic vein treated with transarterial onyx embolization

Intracranial dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous connections that lie within the dura. Intraosseous DAVFs involving diploic venous system are extremely rare. A 46-year-old woman presented with headache and right pulsatile tinnitus for three weeks. The tinnitus started after yelling. Digital subtraction angiography revealed DAVF within the basal portion of right parietal bone along the middle meningeal artery (MMA) groove. The fistula was fed by frontal branch of right MMA and drained into right transverse sigmoid sinus junction through dilated middle meningeal vein. The intraosseous DAVF involving diploic vein was successfully obliterated with Onyx embolization via transarterial route.

Acute respiratory distress syndrome after onyx embolization of arteriovenous malformation

Purpose. We report a case of a 60-year-old male who underwent sequential Onyx embolizations of a cerebral arteriovenous malformation (AVM) which we implicate as the most likely etiology of subsequent acute respiratory distress syndrome (ARDS). Methods. Case report and literature review. Results. Shortly after the second Onyx embolization procedure, the patient declined from respiratory failure secondary to pulmonary edema. Clinical entities typically responsible for pulmonary edema including cardiac failure, renal failure, iatrogenic volume overload, negative-pressure pulmonary edema, and infectious etiologies were evaluated and excluded. The patient required mechanical ventilatory support for several days, delaying operative resection. The patient met clinical and radiographic criteria for ARDS. After excluding other etiologies of ARDS, we postulate that ARDS developed as a result of Onyx administration. The Onyx copolymer is dissolved in dimethyl sulfoxide (DMSO), a solvent excreted through the lungs and has been implicated in transient pulmonary side effects. Additionally, a direct toxic effect of the Onyx copolymer is postulated. Conclusion. Onyx embolization and DMSO toxicity are implicated as the etiology of ARDS given the lack of other inciting factors and the close temporal relationship. A strong physiologic rationale provides further support. Clinicians should consider this uncommon but important complication.

Intraoperative angiography for cranial dural arteriovenous fistula

BACKGROUND AND PURPOSE

IA is a valuable adjunct during surgery for a variety of neurovascular diseases; however, there are no reported series describing IA for DAVFs. This study was undertaken to evaluate the safety and efficacy of IA for DAVFs.

MATERIALS AND METHODS

A retrospective review of DAVF surgical cases during a 20-year period was conducted, and cases with IA were evaluated. Clinical details, surgical and angiographic findings, and postoperative outcomes were reviewed. The incidence of residual fistula on IAs, the utility of the surgical procedure, and the incidence of false-negative findings on IA were also determined.

RESULTS

IA was performed in 29 patients (31 DAVFs) for DAVFs. The distribution of the fistulas was the following: transverse-sigmoid (n = 9), tentorial (n = 6), torcular (n = 3), cavernous sinus (n = 4), SSS (n = 4), foramen magnum (n = 3), and temporal-middle fossa (n = 2). Twelve patients had undergone prior embolization, while 6 patients had unsuccessful embolization procedures. Thirty-eight surgeries were performed for DAVF in 29 patients, and IA was performed in 34 surgeries. Forty-four angiographic procedures were performed in the 34 surgeries. Nine patients underwent multiple angiographies. In 11 patients (37.9%), IA revealed residual fistula after the surgeon determined that no lesion remained. This led to further exploration at the same sitting in 10 patients, while in 1 patient, further surgery was performed at a later date. False-negative findings on IA occurred in 3 patients (10.7%).

CONCLUSIONS

IA is an important adjunct in surgery for DAVF. In this series, it resulted in further surgical treatment in 37.9% of patients. However, there was a 10% false-negative rate, which justified subsequent postoperative angiography.

Microsurgery can cure most intracranial dural arteriovenous fistulae of the sinus and non-sinus type

There is consensus that intracranial dural arteriovenous fistulae (dAVF) with direct (non-sinus-type) or indirect (sinus-type) retrograde filling of a leptomeningeal vein should be treated due to the high risk of neurological deficits and hemorrhage. No consensus exists on treatment modality (surgery and/or embolization) and, if surgery is performed, on the best surgical strategy. This series aims to evaluate the role of surgery in the management of aggressive dAVFs. Forty-two patients underwent surgery. Opening and packing the sinus with thrombogenic material was performed in 9 of the 12 sinus-type dAVFs. In two sinus-type fistulae of the cavernous sinus and 1 of the torcular, microsurgery was used as prerequisite for subsequent embolization by providing access to the sinus. In the 30 non-sinus-type dAVFs, surgery consisted of interruption of the draining vein at the intradural entry point. In 41 patients undergoing 43 operations, elimination of the dAVF was achieved (97.6%). In one case, a minimal venous drainage persisted after surgery. The transient surgical morbidity was 11.9% (n = 5) and the permanent surgical morbidity 7.1% (n = 3). Our surgical strategy was to focus on the arterialized leptomeningeal vein in the non-sinus-type and on the arterialized sinus segment in the sinus-type dAVFs allowing us to obliterate all but one dAVF with a low morbidity rate. We therefore propose that microsurgery should be considered early in the treatment of both types of aggressive dAVFs. In selected cases of cavernous sinus dAVFs, the role of microsurgery is reduced to that of an adjunct to endovascular therapy.

A prospective, multicenter, randomized trial of the Onyx liquid embolic system and N-butyl cyanoacrylate embolization of cerebral arteriovenous malformations

Object

The Onyx liquid embolic system (Onyx) was approved in the European Union in 1999 for embolization of lesions in the intracranial and peripheral vasculature, including brain arteriovenous malformations (AVMs) and hypervascular tumors. In 2001 a prospective, equivalence, multicenter, randomized controlled trial was initiated to support a submission for FDA approval. The objective of this study was to verify the safety and efficacy of Onyx compared with N-butyl cyanoacrylate (NBCA) for the presurgical treatment of brain AVMs.

Methods

One hundred seventeen patients with brain AVMs were treated with either Onyx (54 patients) or NBCA (63 patients) for presurgical endovascular embolization between May 2001 and April 2003. The primary end point was technical success in achieving ≥ 50% reduction in AVM volume. Secondary end points were operative blood loss and resection time. All adverse events (AEs) were reported and assigned a relationship to the Onyx or NBCA system, treatment, disease, surgery, or other/unknown. The Data Safety Monitoring Board adjudicated AEs, and a blinded, independent core lab assessed volume measurements. Patients were monitored through discharge after the final surgery or through a 3- and/or 12-month follow-up if resection had not been performed or was incomplete.

Results

The use of Onyx led to ≥ 50% AVM volume reduction in 96% of cases versus 85% for NBCA (p = not significant). The secondary end points of resection time and blood loss were similar. Serious AEs were also similar between the 2 treatment groups.

Conclusions

Onyx is equivalent to NBCA in safety and efficacy as a preoperative embolic agent in reducing brain AVM volume by at least 50%.

Embolization of cranial dural arteriovenous fistulae with ONYX: Indications, techniques, and outcomes

OBJECTIVES

The purpose of this study was to establish the role of the liquid embolic agent, ONYX, in the treatment of cranial dural arteriovenous fistulae (DAVFs) and to redefine the indications, techniques and outcomes of treatment with ONYX.

MATERIALS AND METHODS

This is a retrospective study of 25 DAVF patients who underwent endovascular treatment with ONYX between February 2006 and July 2008. All patients of DAVF presenting in this period were treated with ONYX.

RESULTS

Anatomic cure (i.e., complete angiographic closure of the fistula) was achieved in a single session and through a single arterial pedicle injection in 21 out of 25 patients (cure rate of 84%). Out of four patients with residual fistulae, one achieved cure that was evident on a control angiogram obtained at 3 months while three had no vascular access for further embolization and so were referred for radiosurgery. There was only one recurrence seen in angiograms obtained at the end of one year and this patient was re-embolized successfully with ONYX. Complications were seen in two patients.

CONCLUSION

ONYX embolization of DAVFs has revolutionized the endovascular treatment of DAVFs, achieving high cure rates in a single session with minimal complications. Transarterial ONYX embolization should be the first option for all locations, except cavernous DAVFs.

Endovascular Treatment of Intracranial Dural Arteriovenous Fistulae Using Onyx: a Case Series

Objective:

An endovascular approach is often the first-line treatment of dural arteriovenous fistulae (DAVFs). Information on the use of Onyx (ev3 Neurovascular, Irvine, CA) for treating DAVFs, however, is limited. Therefore, we present our early experience, technical considerations, and complications associated with the use of Onyx for DAVF embolization.

Methods:

Twenty-eight patients with 29 DAVFs treated with Onyx embolization were included in this analysis. Hospital records, operative reports, and angiograms were reviewed and analyzed.

Results:

Forty Onyx procedures, including 39 transarterial and 1 transvenous approaches, were performed. Fifty-one external carotid artery branches, 8 posterior meningeal artery branches, and 3 internal carotid artery branches were used for Onyx embolization. Branches of the middle meningeal artery were embolized 32 times, and the occipital artery was embolized 15 times. Twenty-one fistulae (72%) were cured angiographically with endovascular therapy. Transarterial embolization via the middle meningeal artery cured 12 DAVFs (41%). Four complications (9.7%) were recorded, including 3 transient (7.3%) and 1 permanent neurological deficits (2.4%). Follow-up imaging, which was available for 8 fistulae with angiographic cures, showed no evidence of recurrence.

Conclusion:

Transarterial Onyx embolization of external carotid artery branches, particularly the middle meningeal artery, offers a high likelihood of cure. This technique provides a safe and effective method of embolization with few side effects and complications. However, long-term follow-up is needed to establish its efficacy.

Use of onyx in the management of tentorial dural arteriovenous fistulae

OBJECTIVE

Tentorial dural arteriovenous fistula (DAVF) is an uncommon disease with a poor natural history. Management of tentorial DAVF remains controversial. This study reports the technique and results of transarterial embolization using Onyx (Micro Therapeutics Inc., Irvine, CA) in the treatment of a series of 14 patients with tentorial DAVFs.

METHODS

We retrospectively reviewed the clinical and radiological data of 14 patients with tentorial DAVFs who were treated by transarterial embolization using Onyx at Shanghai Changhai Hospital between 2005 and 2008.

RESULTS

Twelve patients presented with subarachnoid or intraventricular hemorrhage. Complete cure was achieved in 11 patients after 1 procedure and in 1 patient after 2 procedures. Incomplete cure was obtained in the other 2 patients. One patient experienced vessel perforation; another had microcatheter retention. All of the patients recovered well, except 1 patient who died of severe infection caused by ventricular drainage. Clinical follow-up showed no rebleeding or worsening. Follow-up angiography in 8 patients with total occlusion demonstrated no recurrence.

CONCLUSION

These results suggest that transarterial embolization using Onyx is feasible and effective for the management of tentorial DAVFs.

Histopathological changes in brain arteriovenous malformations after embolization using Onyx or N-butyl cyanoacrylate

Object

The aim of this study was to analyze the histopathological changes in a consecutive series of 32 patients with brain arteriovenous malformations that were resected after undergoing endovascular embolization (22 using Onyx and 10 using N-butyl cyanoacrylate [NBCA]).

Methods

Selections from fixed paraffin-embedded specimens were stained for histological examination with H & E and Verhoeff-van Gieson stain. Lipid dye Oil Red O was used to stain vessel specimens that were embolized using NBCA. Specimens were evaluated for the presence of embolic agent, inflammation, angionecrosis, and evidence of recanalization. These results were correlated with the time interval between the bleeding, embolization, and resection.

Results

The smallest vessel occluded by the embolic agent was 5 μm in the Onyx group and 20 μm in the NBCA group. There was evidence of vascular or perivascular inflammation in 20 (90.9%) of 22 and 9 (90%) of 10 specimens after Onyx and NBCA embolization, respectively. Chronic foreign-body giant cells were observed in 12 (54.5%) of 22 specimens after Onyx embolization, but were absent in specimens after NBCA embolization. Angionecrosis of the embolized vessel was observed in 13 (59.1%) of 22 specimens and in 4 (40%) of 10 specimens after Onyx and NBCA embolization, respectively. There was evidence of recanalization in Onyx embolized vessels in 4 (18.2%) of 22 specimens, and there was no evidence of recanalization after NBCA embolization.

Conclusions

Onyx penetrates much smaller vessels than NBCA. Inflammation occurs with both embolic agents at equal frequency. Evidence of chronic foreign-body giant cells and recanalization after Onyx embolization shows a long-standing reaction to Onyx and raises questions about the permanence of occlusion after Onyx embolization.

Balloon-assisted transarterial embolization of intracranial dural arteriovenous fistulas

OBJECT

The authors report their preliminary experience using a balloon-assisted technique (BAT) in the transarterial embolization of intracranial dural arteriovenous fistulas (DAVFs).

METHODS

The authors reviewed the prospectively collected data obtained in 7 consecutive patients with DAVFs in whom embolization was achieved using transarterially injected Onyx with either the venous or arterial BAT. Procedures were performed at the Division of Interventional Neuroradiology at the University of California at Los Angeles Medical Center between September 2005 and January 2008.

RESULTS

Three patients presented with cortical venous reflux and 4 did not. Three patients underwent transarterial Onyx-based embolization combined with transvenous balloon protection; the balloon was inflated in the transverse sinus in 2 of these patients and in the superior sagittal sinus in the third. One of them underwent an additional transarterial Onyx embolization with arterial BAT, whereas 4 other patients were treated with arterial BAT alone. The occipital artery was temporarily occluded with the balloon in 4 of these cases, whereas in the fifth, the authors used temporary balloon occlusion of the middle meningeal artery. Angiograms obtained immediately after embolization demonstrated complete or near-complete obliteration of the fistula in 6 patients and partial occlusion in 1 patient. There were no immediate or postprocedural complications. Two patients who presented with intracranial hemorrhage never suffered a second hemorrhage, and all other patients experienced either complete resolution or significant improvement of their symptoms.

CONCLUSIONS

The BAT provides a new complementary method in the transarterial embolization of DAVFs that are not amenable to transvenous embolization. The venous BAT protects the patency of critical venous pathways, whereas the arterial BAT provides better control of the Onyx-based embolization.

Combined surgical/endovascular treatment of a complex dural arteriovenous fistula in 21-month-old. Technical note

The treatment of intracranial dural arteriovenous fistulas (AVF) has progressed considerably over the past few decades. With the introduction of new embolic materials and refinement of endovascular techniques, lesions that in the past may have required extensive surgery, or were considered untreatable, have increasingly become curable. Despite improvements in technology, not every condition is amenable to an endovascular treatment, including those patients with preexisting vascular abnormalities that preclude an endovascular approach. In these cases, the patient may be left with suboptimal treatment options with higher associated risks. The authors here report on the treatment of a dural AVF in a pediatric patient in whom prior procedures rendered his cerebrovascular anatomy unnavigable using traditional endovascular techniques. To circumvent these vascular abnormalities the patient underwent combined surgical/endovascular treatment that included surgical exposure and cannulation of the cervical carotid artery, as well as simultaneous femoral artery access, with subsequent successful transarterial embolization of the dural AVF.