Congenital Arteriovenous Fistula in a Nine-Year-Old Child: A Case Report.

Congenital external carotid-jugular fistula is a rare condition caused by altered embryologic development of the vasculature. It is usually treated with surgery or endovascular embolization; controversy exists on the best therapeutic approach and the specific endovascular technique. We report a case of a complex congenital fistula between the external carotid and jugular veins treated with a combined trans-arterial dual microcatheter coiling technique followed by n-BCA (n-butyl cyanoacrylate) glue embolization. After performing a balloon occlusion test to localize the exact fistulous point, dual microcatheter coiling allowed flow reduction and proper packing without balloon assistance. Due to the superficial location of the fistula, the use of n-BCA glue embolization glue guaranteed complete occlusion, avoiding the skin discoloration that Onyx, the standard embolic agent used in fistulas, might cause. This combined endovascular technique provides a safe and simple strategy to optimize efficacy and aesthetic outcomes in a young child with a congenital carotid-jugular fistula.

Subarachnoid Hemorrhage of Unknown Cause after Transvenous Embolization of Transverse Sigmoid Sinus Dural Arteriovenous Fistula Followed by Transarterial Embolization: A Case Report.

Objective: Dural arteriovenous fistula (dAVF) is generally treated by endovascular therapy, but transarterial embolization (TAE) carries the risk of potential complications, including distal migration of embolic material, brain infarction, and venous congestion. Intracranial hemorrhage is infrequent but remains a considerable concern. Case Presentation: A man in the seventh decade presented with left hemiparesis. Brain MRI revealed right corona radiata infarction and incidentally identified a left transverse sigmoid sinus dAVF. Under a diagnosis of Borden type III and Cognard type IIb, an endovascular treatment plan was initiated. After an unsuccessful attempt at transvenous embolization, TAE with Onyx (Medtronic, Minneapolis, MN, USA) successfully resolved the dAVF. However, immediate post-treatment CT revealed subarachnoid hemorrhage, leading to decompressive craniotomy. Follow-up DSA showed no residual shunts, and the cause of the bleeding remained unknown. Conclusion: Despite the unknown cause of bleeding, a thorough evaluation of preoperative hemodynamics and diligent postoperative examination is crucial in managing dAVF cases. Further pathological investigations are needed to gain a comprehensive understanding of such occurrences.

Onyx prevents the bleeding of ruptured aneurysms during interventional embolization.

Endovascular treatment has been acknowledged as an effective treatment for intracranial aneurysms, showcasing favorable clinical outcomes and providing robust protection against rebleeding and rupture. Notably, during the endovascular procedure, significant complications include intraprocedural aneurysmal rupture (IAR) induced by microcatheters, microguidewires, or spring coils, along with thromboembolic events, significantly escalating patient mortality and disability. Current approaches against for IARs involve various strategies such as heparin reversal, compression of the common carotid artery or upstream soft guidewire to mitigate blood flow, management of intracranial pressure and blood pressure, and balloon-assisted or unassisted rapid dense embolization of the aneurysm. Nevertheless, these measures may prove insufficient in halting hemorrhage, especially in scenarios where additional coils cannot be added for dense embolization due to inherent limitations. In this context, we introduce a novel strategy for the prompt, safe, and effective cessation of aneurysm bleeding, which involves injecting an appropriate quantity of Onyx into the aneurysm through a microcatheter while safeguarded by an aneurysm-carrying arterial braided stent. Initially, we attempted dense embolization by filling multiple coils. However, in cases where continued coil filling proved unfeasible or failed to sufficiently prevent contrast agent extravasation, we opted for Onyx injection into the aneurysm. Utilizing Onyx effectively prevented further blood extravasation without adversely impacting the aneurysm-carrying artery or distal vessels, leading to favorable prognoses for all patients. This article delineates our embolization strategy, highlighting the efficacy and safety of Onyx injection as an alternative or complementary measure in managing complications arising from endovascular coil embolization.

Posterior short ciliary arteries ischemia following embolization of anterior ethmoid artery to treat dural arteriovenous fistulas: a case report.

BACKGROUND: The Onyx™ Liquid Embolic System is a non-adhesive liquid embolic agent, which has been proved by the US FDA for embolization of lesions in the peripheral and neurovasculature since 2005. We reported a case of ischemic optic neuropathy after using Onyx-18 to embolize the anterior ethmoid arteries that feeding dural arteriovenous fistulas (DAVF). CASE PRESENTATION: A 57-year-old Asian male presented with anterior cranial fossa DAVF underwent embolotherapy by delivering Onyx-18 through a microcatheter into the anterior ethmoid arteries under angiography guidance. The interventional procedure was successful and no clear evidence was found pointing to untargeted occlusive embolus. But after the surgery the patient experienced delayed painless vision loss in the right eye (RE). The fundoscopy showed unilateral papilledema with pale optic disc in RE, accompanied by significant edema and thickening in the retinal nerve fiber layer (RNFL) of macula. The fundus fluorescence angiography showed that most of the optic disc in RE had postponed or absent fluorescence filling. Visual evoked potential (VEP) confirmed that the amplitude of the P100 component was decreased in RE without significant prolongation of the latency. The patient was diagnosed with anterior ischemic optic neuropathy, but immediate pulse steroid therapy failed to rescue his vision. CONCLUSION: Preoperative evaluation of the patient's hemodynamic status and fundus examination are essential for assessing the risk of ischemic ocular complications, and the non-adhesive liquid embolic agent Onyx-18 should be used cautiously during endovascular embolization of intracranial artery.

Making Neuroendovascular Therapy for Cerebrovascular Disease Using Distal/Trans-radial Artery Access Safer.

Neuroendovascular therapy using distal/trans-radial artery access (d/TRA) has attracted attention as a less invasive procedure. We have selected dTRA or TRA in all cases of carotid artery stenting (CAS). In recent years, TRA has been actively selected for mechanical thrombectomy for acute ischaemic stroke (MT for AIS) and Onyx embolisation for arteriovenous malformations. We compared the patient background, surgical strategy, perioperative complications, and outcome in 41 patients who underwent CAS in the first period (Apr 2017-Feb 2019) and 12 patients in the second period (Apr 2020-Feb 2022) avoiding trans-femoral artery access (TFA) as possible. We compared the patient background, surgical strategy, perioperative complications, and outcome in 46 patients who underwent MT for AIS via TFA from Apr 2022 to Dec 2022 as the first period and five patients who underwent MT for AIS via TRA from Jan 2023 to Sep 2023 as the second period. Concerning CAS, the second period included significantly more symptomatic cases, with a higher rate of edaravone use to prevent hyperperfusion and a significantly smaller sheath diameter. In the second period, CAS was performed in severe conditions; nevertheless, there was no significant difference between the two groups in terms of either the ratio of cases detected by postoperative diffusion-weighted imaging positive or the ratio of cases with puncture site-related complications (PSCs). Concerning MT for AIS, there were no significant differences between the two groups with the patient backgrounds. The percentage of effective reperfusion, time from puncture to recanalisation, and outcome in the second period were all non-inferior to those in the first period when conventional MT for AIS was performed. Even though we introduced d/TRA in patients with cognitive decline and inability to remain at rest during the perioperative period, we completely avoided PSCs via d/TRA. In particular, cerebral hyperperfusion syndrome after CAS and ischaemia-reperfusion injury or re-occlusion after MT were rare but critical perioperative complications, and near-infrared spectroscopy (NIRS) may be used to monitor these problems. We introduced intensive evaluation by NIRS if we had time to spare.

Bailout using NBCA for incomplete onyx embolization of tentorial dural arteriovenous fistula.

Transarterial embolization using Onyx (Medtronic, Irvine, CA, USA) results in a high cure rate for complete obliteration of dural arteriovenous fistulas. However, incomplete obliteration occurs in some cases. Reports on the use of bailout therapy in such cases are limited. A 79-year-old man was diagnosed with Borden type III tentorial dural arteriovenous fistulas during a check-up for a headache. We first performed transarterial embolization with Onyx from a tentorial artery, but the fistula was not completely obliterated. We then performed an additional transarterial embolization with n-butyl-2-cyanoacrylate from the same artery in a single session, and the fistula was successfully bailed out, resulting in complete obliteration. Combining different liquid embolic materials, Onyx and n-butyl-2-cyanoacrylate, is an effective strategy for achieving complete obliteration in incomplete transarterial embolization treatment of dural arteriovenous fistulas.

A novel approach to addressing intercavernous sinus bleeding: Preoperative onyx embolization in the endoscopic endonasal approach for craniopharyngioma resection.

Background: Hemorrhage originating from the intercavernous sinuses during transsphenoidal approaches for skull base injury is a common occurrence, but it can be easily controlled. However, in specific cases, it may necessitate suspending the surgery or result in hemodynamic instability. Case Description: We present the case of a 7-year-old female patient who underwent transsphenoidal endoscopic endonasal for craniopharyngioma resection. The patient's parents gave consent for the procedure. During the procedure, significant intraoperative bleeding occurred, which was necessary to stop the resection. After the surgery, cerebral angiography was performed, which identified a prominent anterior intercavernous venous sinus as the source of the bleeding. A successful embolization using onyx was performed, leading to a satisfactory postoperative recovery without any complications. The patient then underwent a second surgical intervention for the resection of the craniopharyngioma through an endoscopic endonasal transsphenoidal approach. This procedure achieved a complete resection of the lesion without complications, and the patient experienced an adequate postoperative recovery. Conclusion: The objective of this case is to describe a previously unreported technique involving onyx embolization for controlling prominent bleeding from the intercavernous sinus and as a presurgical embolization method to reduce the risk of bleeding during endoscopic endonasal surgery for resection of a craniopharyngioma.

Percutaneous preoperative embolization with onyx in the management of a carotid body tumor: A case report.

Carotid body tumors (CBTs) are rare, hypervascular neuroendocrine neoplasms that can lead to significant complications during surgical resection due to the high risk of bleeding. We present the case of a 64-year-old male with a palpable neck mass on the left side, diagnosed as a CBT through imaging studies. Given the tumor's increasing size and rich vascularization, percutaneous preoperative embolization with Onyx under ultrasound and angiographic guide, was performed to minimize intraoperative complications. Forty-eight hours later, the tumor was surgically resected with minimal blood loss and no injury to cranial nerves or the carotid bifurcation.

1-Year outcomes of Resolute Onyx Zotarolimus-Eluting Stent for symptomatic intracranial atherosclerotic disease: A multicenter propensity score-matched comparison with stenting versus aggressive medical management for preventing recurrent stroke in intracranial stenosis trial.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is one of the most prevalent causes of stroke across the world. Endovascular treatment has gained prominence but remains a challenge with unfavorable results. Recent literature has demonstrated that the Resolute Onyx Zotarolimus-Eluting Stent (RO-ZES) is a technically safe option with low complication rates along with 30-day outcomes associated with intracranial stent placement for ICAD with RO-ZES compared to results from the Stenting Versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial. Here, we aim to compare outcomes at one year with the SAMMPRIS trial with a multicenter longitudinal study. MATERIALS AND METHODS: Prospectively maintained databases across seven stroke centers were analyzed for adult patients undergoing RO-ZES placement for ICAD between January 2019 and May 2023. The primary endpoint was composite of one-year stroke, ICH, and/or death. These data were propensity score matched using age, sex, hypertension, diabetes mellitus, smoking status, and impacted vessel for comparison between RO-ZES and the SAMMPRIS percutaneous angioplasty and stenting groups (S-PTAS). RESULTS: A total of 104 patients were included, mean age ± SD: 64.9 ± 10.9 years, 25.5% female. Propensity score match analysis of the 104 patients with S-PTAS demonstrated one-year stroke, ICH, and/or death rate of 11.5% in the RO-ZES group and 28.1% in the S-PTAS group (odds ratio 4.17, 95% CI 2.06-8.96, p = 0.001). CONCLUSION: The RO-ZES system demonstrates strong potential to reduce long-term complications at one year compared with the S-PTAS group. Further prospective multicenter studies are needed to corroborate and build upon these findings.

Evaluation of the Properties of 3D-Printed Onyx-Fiberglass Composites.

This study evaluated the properties of 3D-printed Onyx-fiberglass composites. These composites were 3D-printed with zero, one, two, three, and four layers of fiberglass. Ten samples of each configuration were printed for the tensile and flexural tests. The average tensile strength of the Onyx specimens was calculated to be 44.79 MPa, which increased linearly by approximately 20-25 MPa with each additional fiberglass layer. The elastic moduli calculated from the micromechanics models were compared with the experimental values obtained from the tensile tests. The experimental elastic modulus increased more significantly than the model prediction when more fiberglass layers were added. The flexural modulus of Onyx was 17.6 GPa, which increased with each additional fiberglass layer. This quantitative analysis of composites fabricated using 3D printing highlights their potential for commercialization and industrial applications.

Endovascular Embolization in a Rare Case of Left Basal Ganglia Large Arteriovenous Malformation with Hydrocephalus: A Case Report.

Brain arteriovenous malformation (AVM) is a rare congenital disorder affecting young adults with an incidence of 0.94 per 100,000 population. Intracranial digital subtraction angiography has to be done in all patients and grading of AVM is done as per Spetzler-Martin grading. We report a rare case of left basal ganglia large AVM treated by endovascular embolization. Our experience with endovascular embolization using Onyx is successful in the treatment of large brain AVM. Endovascular embolization with Onyx is safe and feasible in deeply located large AVMs of the brain. Our patient has postoperatively recovered completely without any neurological deficit.

Grouting technique-combining transvenous Onyx and coils for the embolization of complex non-cavernous intracranial dural arteriovenous fistulas.

Objective: Incomplete occlusion of cerebral dural arteriovenous fistula (DAVF) may lead to fistula recurrence and rebleeding, which may necessitate several embolizations and lead to worse clinical outcomes. Herein, we describe a grouting technique for endovascular embolization and its outcomes in a series of patients with complex intracranial DAVF. Methods: A total of 20 patients with aggressive type or symptomatic intracranial non-cavernous DAVF underwent endovascular transvenous embolization combining detachable coils and Onyx. Two microcatheters were positioned either in the distal segment of the involved sinus or near the draining veins. To achieve tight occlusion of the involved sinus, coils were carefully delivered through the first microcatheter, starting from the distal segment and then to the proximal segment. Next, Onyx was injected through the second microcatheter to reinforce and fill (grout) the interspace of coil mass and gradually refluxed to the mural channels and para-sinus cortical veins until the fistula was completely occluded. Results: Successful embolization was achieved in all 20 patients. The initial angiographic results revealed the achievement of complete occlusion in 19 patients (95%). At the postembolization follow-up, complete obliteration of the fistula was achieved in all patients (100%). No symptom or angiographic recurrence was observed at the 2- to 5-year follow-ups. No patient required additional embolization or stereotactic radiosurgery. Conclusion: The proposed grouting technique combining detachable coils and Onyx appears to be promising for the elimination of complex intracranial non-cavernous DAVFs.

Value of Dual Arterial Access for Improved Angiographic Control for Double-Lumen Arterial Balloon Onyx Embolization of Multifeeder Complex Cranial Dural Arteriovenous Fistulas: A Technical Nuance.

BACKGROUND: Here we describe our experience managing intracranial dural arteriovenous fistulas (DAVFs) via endovascular embolization using a transarterial embolization (TAE) technique with liquid embolic agents. We illustrate the technical nuance of using dual arterial access for angiographic control runs in complex DAVFs supplied by multiple feeders from 2 distinct arterial systems. METHODS: Retrospective analysis of intracranial DAVF embolization as a single treatment technique at our institution from 2013 to 2023. RESULTS: Twenty-three patients with intracranial DAVF who underwent endovascular treatment as their initial treatment were included. All embolizations were approached transarterially with Onyx (n = 19), n-butyl cyanoacrylate (n = 2), or a combination (n = 2). Twenty-two patients (96%) had angiographic evidence of complete fistula obliteration after initial embolization. Six DAVF TAEs were performed with dual arterial access for simultaneous embolic delivery and angiographic control intraoperatively. Two patients recanalized twice postprocedure, 1 of whom was found to have incidental new DAVF at follow-up. Median patient follow-up was 12 months (interquartile range, 6-36 months), with a median modified Rankin Scale score on discharge of 1 and a Glasgow Outcome Scale score at 3 months of 5. CONCLUSIONS: In this initial series of patients with DAVF managed by endovascular embolization, dual arterial access was feasible, safe, and effective in achieving fistula obliteration. Dual-arterial access conveniently provides simultaneous access for control angiography and embosylate delivery intraoperatively.

Evaluating the Potential of Preembolization Using Ethylene-Vinyl Alcohol (Onyx and Squid) in Carotid Body Tumor Paraganglioma.

OBJECTIVE: This study aims to evaluate the efficacy and safety of preoperative embolization, used 48 hours before surgery to reduce tumor size and surgical complications in carotid body paragangliomas. METHODS: This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis and Cochrane Handbook. A comprehensive literature search was performed in Medline, Embase, Web of Science, and Cochrane databases. The inclusion criteria were: 1) observational studies, 2) reporting on diagnosed carotid body paragangliomas, 3) undergoing preoperative embolization procedures, and 4) with ethylene-vinyl alcohol as an embolic agent. RESULTS: The study analyzed 106 patients, aged 18-79, using primarily Onyx 18 for embolization, with treatment intervals ranging from 24 hours to 2 weeks. Efficacy outcomes showed near-total devascularization in 67% of cases (95% confidence interval [CI]: 0.47-0.87; I² = 74%), subtotal devascularization in 33% (95% CI: 0.12-0.54; I² = 43%), and total devascularization in 97% (95% CI: 0.88-1.00; I² = 41%), indicating significant heterogeneity across outcomes. The mean estimated blood loss was 184.46 ml (95% CI: 116.72-252.20 ml). Postembolization complication rate was exceptionally low at 1% (95% CI: 0.00-0.06; I² = 0%). CONCLUSIONS: In conclusion, preoperative embolization of carotid body tumors achieved high rates of devascularization with minimal blood loss and a very low incidence of complications, highlighting its effectiveness and safety as a treatment strategy.

Bilhemia After Percutaneous Liver Tumor Core Biopsy With the Percutaneous Embolization of Bilio-venous Fistula With Coils and Onyx.

Bilhemia is a rare but potentially lethal condition representing abnormal communication and flow of bile into the bloodstream. We present a case of iatrogenic bilhemia after a percutaneous liver biopsy in a patient with cholangiocarcinoma. The bilio-venous fistula was visualized with percutaneous cholangiography and successfully embolized using coils and the liquid embolic agent Onyx. To our knowledge, this is the first report of using Onyx for the embolization of a bilio-venous fistula.

Technological optimization and fatigue evaluation of carbon reinforced polyamide 3D printed gears.

Nowadays, this is even more challenging while additive manufacturing technology is used for prototyping, as well as the production of gearing systems. Presented is an optimization and characterization of the additively manufactured (AM) gears made of carbon-reinforced polyamide material in correlation to conventional polymer gearings. Based on the obtained results, the fatigue life data for AM carbon-reinforced Polyamide gears is calculated and compared to traditionally produced Polyamide 66-based gears. Results show that the durability of AM-produced carbon-reinforced Polyamide gears can be compared to conventional-produced Polyamide 66-based gears. Furthermore, deduced that wear of the AM-reinforced Polyamide teeth, can be closely connected with the meshing temperature in correlation with fatigue.

Facial nerve palsy after ethylene vinyl alcohol arterial embolization of glomus tympanicum.

BACKGROUND & OBJECTIVE: Glomus tympanicum and jugulare tumors are highly vascular and are therefore commonly embolized before surgical resection to prevent intra-operative bleeding. We report a case of facial nerve paralysis after pre-operative embolization for a glomus tympanicum tumor with ethylene vinyl alcohol (EVOH also known as Onyx) embolic agent. We discuss the choice of embolic agent in relation to the risk of this complication and potential management strategies. METHODS: A 57F with right glomus tympanicum developed right facial nerve palsy immediately after embolization. She received 24 mg of dexamethasone over the course of 24 h immediately following her embolization, surgical facial nerve decompression concurrent with tumor resection, and a 10-day prednisone taper. Our main outcome measure was facial nerve function on follow-up physical examinations. RESULTS: The patient developed right facial paralysis (HB 6/6) after Onyx embolization of branches of the external carotid artery system, likely due to translocation of embolic agent into facial nerve vasa nervosa as seen on post-embolization CT. No immediate improvement was observed with high dose steroids and decompression, however over the next 6 months her facial nerve function began to improve (HB 3/6). CONCLUSIONS: Surgical excision is the standard of care for glomus jugulare and glomus tympanicum tumors. Due to their propensity to bleed, their arterial feeders (branches of the external carotid) are often embolized prior to surgery, however, facial nerve paralysis is a rare but serious complication. There is a possible relationship between the choice of embolic agent and this complication. Though facial palsy is of sufficient rarity that no standard treatment pathway exists, due to the impact on a patient's quality of life, we recommend aggressive therapy to salvage nerve function.

Intracranial hypertension secondary to unruptured pial arteriovenous malformation. Suitability of isolated endovascular treatment with ethylene vinyl alcohol/dimethyl sulfoxide (Onyx®). Case report and literature review.

A 36-year-old male presented to the Emergency Department with clinical symptoms of blurred vision of progressive onset of two years of evolution. The ophthalmological examination revealed the existence of bilateral papilledema. Using cranial computed tomography and magnetic resonance imaging, the presence of a right occipital pial arteriovenous malformation was certified. Arteriographically, pial arterial contributions dependent on the right middle cerebral artery and the right posterior cerebral artery were identified. Venous drainage was located at the level of the superior sagittal sinus. An associated right transverse sinus stenosis was also identified. The existence of secondary intracranial hypertension was corroborated by monitoring with an intracranial pressure sensor. An interventional procedure was carried out consisting of embolization of the arterial supplies of the lesion using Onyx®. The clinical-radiological findings after the procedure were favorable: the papilledema disappeared and complete exclusion of the malformation was achieved. A new intracranial pressure measurement showed resolution of intracranial hypertension. Subsequent regulated radiological controls showed complete exclusion of the malformation up to 5 years later.

Initial Experience with the Eclipse Double-Lumen Balloon Catheter for Embolization of Cranial Vascular Malformations.

BACKGROUND: Double lumen balloon catheters (DLBCs) have emerged as a potential alternative to single lumen balloon catheters for endovascular embolization of arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). This study describes our preliminary experience with the Eclipse 2L DLBC in treating AVMs and dAVFs. METHODS: Patients who underwent embolization of cranial dAVFs or AVMs at our institution from August 2021 to March 2024 were included. Spinal vascular malformations were excluded. Descriptive statistics were used to analyze procedural outcomes, technical nuances, and postoperative outcomes on follow-up. RESULTS: Twenty-five patients who underwent 38 embolization procedures (15 AVMs and 23 dAVFs) met criteria for inclusion in this study. The mean age of the cohort was 52.44 (standard deviation = 17.26), and 48% of the overall cohort (n = 13) was female. The average procedure times for AVMs and dAVFs were 80.4 minutes and 96.73 minutes, respectively. There was 1 instance of catheter entrapment. Two patients in the AVM cohort experienced mortality, and 1 experienced postoperative rupture. CONCLUSIONS: Our preliminary experience using the Eclipse 2L balloon catheter for Onyx embolization reported procedural outcomes comparable to other DLBCs despite relatively higher procedure times and radiation doses. Further long-term studies on its efficacy as primary modality in treating AVMs and dAVFs are encouraged.

Direct tumoral puncture embolization of onyx before endoscopic endonasal resection of a massive juvenile angiofibroma for a patient with Von Willebrand disease - A case report and review of literature.

INTRODUCTION: Standard treatment of a juvenile angiofibroma (JNA) is surgical resection, usually with an endoscopic endonasal surgery and a preoperative embolization. However, standard intra-arterial embolization may fail to completely devascularize tumors. A novel technique of direct intranasal intratumoral onyx embolization has been described. The aim of this study is to demonstrate the safety and the usefulness of this embolization technique on a pediatric case of JNA and to compare our results to previously reported cases. PRESENTATION OF CASE: A twelve-year-old patient suffering from Von Willebrand disease presented with a voluminous JNA with intracranial extension. Internal carotid artery (ICA) branches partially vascularized the tumor. The patient had two previous incomplete surgical resections, which were preceded by a standard embolization, due to massive perioperative bleeding. DISCUSSION: A direct intratumoral embolization of onyx safely allowed complete tumoral devascularization. Tumoral resection was then completed by an endonasal endoscopic approach. Surgery time was decreased (4,5 h versus 5,5 and 6,5 h) and blood loss were minimized (300 ml versus 1 l and 1,3 l). No complication occurred. Twelve articles previously reported this embolization technique. We present the first reported case of onyx embolization being used for a pediatric patient with a coagulation disorder and a voluminous tumor. CONCLUSION: A direct intratumoral onyx embolization allowed complete resection of a massive JNA, for a patient with Von Willebrand disease. Our data suggest that this technique is safe and may be instrumental for a JNA's resection, even if little vascularization comes from ICA branches.