Liquid Embolic Agent Onyx Research Articles

Strategies and outcomes of endovascular treatment of posterior inferior cerebellar artery aneurysms: a single center experience.

To explore safe and reliable strategies and outcomes of endovascular procedures in the treatment of posterior inferior cerebellar artery (PICA) aneurysms. Retrospectively reviewed and analyzed the cases of PICA aneurysms that undergone endovascular therapy from July 2017 through January 2022 in our neurosurgical center, as well as outcomes of long-term follow-up. Total 24 cases were enrolled. Majority of the PICA aneurysms (87.5%, 21/24) presented initially with subarachnoid hemorrhage (SAH) and only 3 cases were not ruptured when they were clinically diagnosed as PICA aneurysms. The patients were endovascularly given either aneurysm occlusion with selective coils (12 cases), embolization of aneurysms and parent arteries (7 cases: 3 cases with coils and 4 cases with Onyx liquid embolic agent), or stent-assisted coiling of the aneurysms (5 cases). One patient, who had comorbidity of intracranial hemorrhage and severe cerebral vasospasm, declined further post-surgery therapy, and discharged from the hospital with anticipation of poor outcome. The rest 23 patients were followed up for 3-24 months with a recurrence rate of 17.4% (4/23). Endovascular procedure of embolizing PICA aneurysms with selective coils or stent-assisted coils is feasible, safe, and reliable. Simplified embolization of the aneurysms or occlusion of the parent artery is recommended as the first choice for the ruptured and bleeding PICA aneurysms.

Onyx Liquid Embolic Agent: Basic Knowledge for Its Use in Interventional Neuroradiology

Onyx Liquid Embolic Agent: Basic Knowledge for Its Use in Interventional Neuroradiology

Letter to the Editor Regarding: “Endoscopic Contralateral Interhemispheric Transfalcine Keyhole Approach for Large Falcine Meningiomas”

A 39-year-old male presented to our institution after sustaining a gunshot wound to the face. He was initially unresponsive with bleeding from the nares bilaterally and was intubated for airway protection. A computed tomography angiogram of the head and neck demonstrated multiple foci of active extravasation in the left maxillary sinus. The patient was taken for emergent neuroendovascular intervention, during which a large, 6.1 mm × 6.4 mm pseudoaneurysm of the left pterygoid artery was discovered and embolized with Onyx liquid embolic agent, with subsequent complete obliteration of the pseudoaneurysm. Embolization immediately halted the bleeding. The patient was neurologically intact at his most recent follow-up appointment. This case demonstrates the importance of obtaining an emergent computed tomography angiography for patients with ballistic facial trauma and early involvement of endovascular neurosurgery for treatment of intractable sinonasal bleeding.

Pseudoaneurysm of the Pterygoid Artery After a Gunshot to the Face

A 39-year-old male presented to our institution after sustaining a gunshot wound to the face. He was initially unresponsive with bleeding from the nares bilaterally and was intubated for airway protection. A computed tomography angiogram of the head and neck demonstrated multiple foci of active extravasation in the left maxillary sinus. The patient was taken for emergent neuroendovascular intervention, during which a large, 6.1 mm× 6.4 mm pseudoaneurysm of the left pterygoid artery was discovered and embolized with Onyx liquid embolic agent, with subsequent complete obliteration of the pseudoaneurysm. Embolization immediately halted the bleeding. The patient was neurologically intact at his most recent follow-up appointment. This case demonstrates the importance of obtaining an emergent computed tomography angiography for patients with ballistic facial trauma and early involvement of endovascular neurosurgery for treatment of intractable sinonasal bleeding.

Surgical Ligation of Spinal CSF-Venous Fistulas after Transvenous Embolization in Patients with Spontaneous Intracranial Hypotension.

A spinal CSF-venous fistula is an increasingly recognized type of CSF leak that causes spontaneous intracranial hypotension. The detection of these fistulas requires specialized imaging such as digital subtraction myelography or dynamic CT myelography, and several treatment options are available. A novel treatment for these CSF-venous fistulas consisting of transvenous embolization with the liquid embolic agent Onyx has been described recently, but some patients require further treatment if embolization fails. The purpose of this study was to evaluate the safety and effectiveness of surgery following transvenous embolization. In a series of 6 consecutive patients who underwent surgical ligation of the fistula after endovascular embolization, there were no surgical complications. Postoperatively, complete resolution of symptoms was reported by 5 of the 6 patients, and brain MR imaging findings of spontaneous intracranial hypotension resolved in all patients. This study suggests that surgical ligation of spontaneous spinal CSF-venous fistulas after endovascular embolization is effective and safe.

Impact of Pre-operative Embolization With Onyx for Brain Arteriovenous Malformation Surgery.

ObjectiveTo clarify the safety and efficacy of pre-operative embolization using Onyx liquid embolic agent (Onyx; ev3) compared with N-butyl cyanoacrylate (NBCA; Cordis Neurovascular, Inc.) or coils in cerebral arteriovenous malformation (AVM) surgery.MethodsThis was a retrospective review of a prospectively collected clinical database of brain AVMs treated at our institute from January 2005 to March 2021. A total of 38 consecutive patients who underwent AVM resection after pre-operative embolization were included. Based on pre-operative embolization materials, the patients were divided into the pre-Onyx group (n = 16), in which NBCA or coils were used for embolization, and the Onyx group (n = 22). Patient characteristics and treatment results were compared between the two groups.ResultsPatient characteristics were comparable between the two groups in terms of age, sex, and rupture status. While the Spetzler–Martin grade was also similar between the two groups, the location of the AVM nidus in the eloquent area was slightly higher in patients in the Onyx group (72.7%) than in patients in the pre-Onyx group (43.8%) (P = 0.09). The embolization rate was higher in the pre-Onyx group (mean: 63.0%; range: 12.7–100%) than in the Onyx group (mean: 50.0%; range: 15.8–100%), but the difference was not statistically significant (P = 0.06). The time needed for surgical removal was shorter in the Onyx group (mean: 354.8 min; range: 144–884 min) than in the pre-Onyx group (mean: 457.9 min; range: 240–1,294 min); however, this difference was not statistically significant (P = 0.13). The amount of intraoperative bleeding was significantly lower in the Onyx group (mean: 129.8 ml; range: 20–540 mL) than in the pre-Onyx group (mean: 448.8 mL; range: 120–1,550 ml) (P = 0.0008). The surgical complication rates were comparable between the two groups (pre-Onyx group, 18.8%; Onyx group, 4.5%; P = 0.29).ConclusionsPre-operative embolization with Onyx can significantly reduce the amount of intraoperative bleeding in AVM resection and may contribute to safe AVM surgery.

Iterative Metal Artifact Reduction (iMAR) of the Non-adhesive Liquid Embolic Agent Onyx in Computed Tomography

BackgroundA drawback of Onyx, one of the most used embolic agents for endovascular embolization of intracranial arteriovenous malformations (AVM), is the generation of imaging artifacts (IA) in computed tomography (CT). Since these artifacts can represent an obstacle for the detection of periprocedural bleeding, this study investigated the effect of artifact reduction by an iterative metal artifact reduction (iMAR) software in CT in a brain phantom.MethodsTwo different in vitro models with two-dimensional tube and three-dimensional AVM-like configuration were filled with Onyx 18. The models were inserted into a brain imaging phantom and images with (n = 5) and without (n = 10) an experimental hemorrhage adjacent were acquired. Afterwards, the iMAR algorithm was applied for artifact reduction. The IAs of the original and the post-processed images were graded quantitatively and qualitatively. Moreover, qualitative definition of the experimental hemorrhage was investigated.ResultsComparing the IAs of the original and the post-processed CT images, quantitative and qualitative analysis showed a lower degree of IAs in the post-processed images, i.e. quantitative analysis: 2D tube model: 23.92 ± 8.02 Hounsfield units (HU; no iMAR; mean ± standard deviation) vs. 5.93 ± 0.43 HU (with iMAR; p < 0.001); qualitative analysis: 3D AVM model: 4.93 ± 0.18 vs. 3.40 ± 0.48 (p < 0.001). Furthermore, definition of the experimental hemorrhage was better in the post-processed images of both in vitro models (2D tube model: p = 0.004; 3D AVM model: p = 0.002).ConclusionThe iMAR algorithm can significantly reduce the IAs evoked by Onyx 18 in CT. Applying iMAR could thus improve the accuracy of postprocedural CT imaging after embolization with Onyx in clinical practice.

The impact of software-based metal artifact reduction on the liquid embolic agent Onyx in cone-beam CT: a systematic in vitro and in vivo study

BackgroundOnyx is frequently used for endovascular embolization of intracranial arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs). One drawback of using Onyx is the generation of artifacts in cone-beam CT...

Recurrent massive hemoptysis in a patient with cystic fibrosis: balloon assisted Onyx embolization after bronchial artery coil recanalization

BackgroundAlthough not standard of care, Cystic Fibrosis patients with recurrent hemoptysis occasionally have coil embolization of bronchial arteries. In the event of recanalization of these arteries in this specific subset of patients, the presence of indwelling coils makes the prospect of conventional particle embolization more difficult, preventing both adequate catheterization of the coiled segment and reflux of the particles.Case presentationIn this report, we describe a case of bronchial artery embolization of a complex Cystic Fibrosis patient with massive hemoptysis from recanalized coiled bronchial arteries utilizing a Scepter Balloon Catheter® (Microvention Terumo, USA) in administration of the liquid embolic agent Onyx® (Medtronic, USA).ConclusionsThe Scepter occlusion balloon catheter allowed for careful placement of the tip within the interstices of the pre-existing coils, allowing for Onyx injection directly into the coil mass without reflux, reconfirming the benefits of Onyx embolization in bronchial artery embolization and providing evidence that the Scepter occlusion balloon catheter should be added to the armamentarium of devices used in complex bronchial artery embolization for Cystic Fibrosis patients with massive hemoptysis.

INCIDENTAL FINDING OF ONYX EMBOLIZATION OF THE PULMONARY ARTERY: A RARE COMPLICATION OF HIGH FLOW DURAL ARTERIOVENOUS FISTULA REPAIR

SESSION TITLE: Medical Student/Resident Imaging Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Onyx® is a non-adhesive liquid embolic agent used for embolization of brain arteriovenous malformations (bAVMs). We present a case of a 58 year-old woman with shortness of breath found to have a foreign body on chest imaging later determined to be a pulmonary artery Onyx embolus. CASE PRESENTATION: A 58 year-old woman with history of tracheostomy-dependent chronic respiratory failure and dural arteriovenous fistula (DAVF) status post multistage embolic repair presented to the emergency department with shortness of breath, chest tightness, and productive cough for one week. On arrival, she was hypoxic requiring 4L oxygen via tracheostomy mask to maintain an oxygen saturation of 94%. Her exam was remarkable for expiratory wheezes in all lung fields and purulent secretions from her tracheostomy. Chest radiograph revealed a linear radiopaque foreign body overlying the expected location of the right pulmonary artery. A computed tomography of the chest confirmed the finding of a tortuous metallic foreign body within the lower lobe branches of the right pulmonary artery. No lung parenchymal changes were noted in the area supplied by these vessels. Interventional radiology reviewed these images and determined the foreign body to be an irretrievable embolus of the agent used during her DAVF repair, her final treatment having occurred three months prior. This finding was of no significance to the patient’s presentation. She was diagnosed with viral tracheitis and managed symptomatically with complete resolution of symptoms. DISCUSSION: The Onyx liquid embolic agent is made of ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide and suspended micronized tantalum powder to make it radio-opaque. It is designed to harden within five minutes of deployment and available in two different formulations varying in viscosity. The lower viscosity Onyx 18 will travel further from the deployment catheter compared to the higher viscosity Onyx 34. Its non-adhesive nature and ease of use makes it a preferable choice to the cyanoacrylate-based (“glue”) agents for some neurointerventionalists. Common complications include hemorrhage, stroke and vessel perforation. Embolus migration has been rarely reported. It is usually noted incidentally on follow-up imaging, as happened with our patient. Clinical presentations are typically asymptomatic, though there have been reports of acute presentations of hypoxemia and superior vena cava syndrome. Treatment options include conservative measures, retrieval of embolus or medical management of symptoms. CONCLUSIONS: Brain AVMs are increasingly being treated with Onyx embolization. Distal migration to non-targeted vessels can be a complication of this procedure, which may be discovered as a puzzling incidental or less commonly an acute finding. Reference #1: FDA, Access Data - Onyx Liquid Embolic system, Instructions for Use, 2003, Site: https://www.accessdata.fda.gov/cdrh_docs/pdf3/P030004c.pdf Reference #2: Tolly, B. T., Kosky, J. L., Koht, A., & Hemmer, L. B. (2016, August 31). A Case Report of Onyx Pulmonary Arterial Embolism... : A&A Practice. LWW. https://journals.lww.com/aacr/fulltext/2017/02150/A_Case_Report_of_Onyx_Pulmonary_Arterial_Embolism.7.aspx#JCL-P-13 Reference #3: Crusio, R., Ramachandran, K., Ramachandran, K., Kupfer, Y., & Tessler, S. (2011). Superior vena cava syndrome caused by embolisation of liquid Onyx. BMJ case reports, 2011, bcr1120103502. https://doi.org/10.1136/bcr.11.2010.3502 DISCLOSURES: No relevant relationships by Timothy Miett, source=Web Response No relevant relationships by Nishka Shetty, source=Web Response

신경혈관 중재술에서의 신경계감시의 역할: 척추 동정맥 기형의 증례

Endovascular embolization is one of the treatment options for spinal arteriovenous malformation (AVM). Intraoperative neurophysiological monitoring (IONM) is widely used in procedures where post-procedure neurological deterioration may occur. 24-year-old man, previously diagnosed with spinal AVM, visited a tertiary hospital complaining of weakness and tingling sensation on both lower extremities. After confirming the right 6th thoracic segmental artery as the target point of the AVM feeder, an endovascular procedure was performed with IONM. During embolization using a nonadhesive liquid embolic agent (Onyx^®), the amplitude of motor evoked potentials of the bilateral tibialis anterior and right abductor hallucis brevis were decreased over the alarm criteria. After the procedure, the patient developed weakness in both legs, hypoesthesia, and neurogenic bladder. After 4 weeks of rehabilitation, motor and bladder function partially improved. This case presentation is to emphasize the role of the continuous multimodality IONM in making important decisions during neuroendovascular procedures.

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

ObjectiveTo retrospectively review the outcome of patients with dural arteriovenous fistula of the anterior cranial fossa (afDAVF) treated by transarterial embolization. Material and methodsSix consecutive patients were referred to our hospital for afDAVF treatment. After a multidisciplinary discussion, they underwent endovascular embolization with Onyx injection through the ophthalmic artery. Their clinical presentation, management and outcomes were retrospectively assessed. ResultsAll interventions were performed with the liquid embolic agent Onyx through the transarterial route from the ophthalmic artery to access the fistulous point. All patients showed a good outcome with complete afDAVF obliteration. ConclusionThis study demonstrates that afDAVFs can be safely and completely obliterated by transarterial embolization via the ophthalmic artery.

Extravasation control with preserved vessel patency after wire perforation during neurothrombectomy: Case report and literature review

Parallel to a more widespread application of endovascular neurothrombectomy in acute ischemic stroke, it is critical to understand the nature and management of associated complications, including wire perforation of the middle cerebral artery (MCA). Sacrifice of the perforated vessel may be necessary to avoid fatal intra-cranial hemorrhage. Here we describe a case of right MCA distribution ischemia complicated by a right MCA perforation. Using super selective injection of contrast through a microcatheter, the point of extravasation was located and sealed with liquid embolic agent (Onyx) while preserving patency of the MCA. By avoiding vessel sacrifice, blood perfusion to distal areas was preserved and therefore the patient was discharged with minimal neurological impairment. Causes of perforation and technical aspects to control extravasation are further discussed.

Treatment of Type I Endoleaks Using Transcatheter Embolization With Onyx

To report a single-center experience with transcatheter embolization of type I endoleaks using the liquid embolic agent Onyx, an ethylene vinyl alcohol copolymer. Eight patients (4 men; mean age 74.8 years, range 63-86) with 10 type I endoleaks (6 abdominal and 4 thoracic) diagnosed 2 days to 9 years after endovascular repair were treated with Onyx embolization because cuff extension was precluded by an insufficient landing zone in 6 cases and an unsuitable aortic diameter in 2. Endoleaks were accessed with a 4-F diagnostic catheter and a coaxially introduced dimethylsulfoxide-compatible microcatheter. Onyx-34 was predominantly applied due to its high viscosity; patent side branches were coil embolized prior to Onyx delivery in 3 cases. Technical success of the procedure was achieved in all cases. The mean volume of Onyx used for abdominal endoleaks was 11.8 mL (range 3.0-25.5) and 19.4 mL (range 4.5-31.5) for thoracic endoleaks. The average duration of the procedure was 76.7 minutes (range 34.5-110.6), and the average radiation dose area product was 18.8 cGy*cm (2) (range 10.6-55.8). Reperfusion of the endoleak was detected in one case 2 days after the procedure. A second case showed an occluded endoleak but a small trace of contrast between the aortic wall and the stent-graft. Non-target embolization was not found in any case. Mean follow-up was 13.2 months (range 8-24). The mean reduction in diameters for thoracic aneurysms after 6 and 12 months was 0.4 and 0.9 cm, respectively, and 0.6 and 1.2 cm, respectively, for abdominal aneurysms. Transcatheter embolization of type I endoleaks using Onyx is a simple, safe, and sustainable treatment option with a high primary success rate for cases in which stent-graft extension is not possible. The benefit of additional coil embolization remains uncertain.

Endovascular treatment of distal intracranial aneurysms with Onyx 18/34

ObjectiveSurgical clipping and coil embolization of distally located intracranial aneurysms can be challenging. The goal of this study was to assess the feasibility, safety and efficacy of treatment of distal aneurysms with the liquid embolic agent Onyx 18/34. MethodsSixteen patients were treated with Onyx 18/34 for distally located aneurysms in our institution between March 2009 and September 2012. The technique consists of occluding the aneurysm as well as the parent vessel at the level of aneurysm with Onyx 18 or 34. Candidates for this treatment were patients with distal aneurysms including mycotic aneurysms, dissecting aneurysms, and pseudoaneurysms in which coiling was considered impossible. ResultsOf the 16 patients, 12 presented with subarachnoid and/or intracerebral hemorrhage. Median aneurysm size was 4.6mm. Aneurysm locations were as follows: Posterior inferior cerebellar artery (n=5), distal anterior inferior cerebellar artery (n=3), distal pericallosal (n=3), distal anterior cerebral artery (n=3), lenticulostriate artery (n=1), and anterior ethmoidal artery (n=1). There were 4 mycotic aneurysms. Complete aneurysm obliteration was achieved in all 6 patients with available angiographic follow-up. There was only 1 (6.3%) symptomatic complication in the series. There were no instances of reflux or accidental migration of embolic material. Favorable outcomes were noted in 82% of patients at discharge. Two patients with mycotic aneurysms died from cardiac complications of endocarditis. No aneurysm recanalization or rehemorrhage were seen. ConclusionParent vessel trapping with Onyx 18/34 offers a simple, safe, and effective means of achieving obliteration of distal challenging aneurysms.

Double-lumen arterial balloon catheter technique for Onyx embolization of dural arteriovenous fistulas: initial experience

BackgroundDural arteriovenous fistulas are vascular malformations with variable clinical symptoms that range in severity from completely asymptomatic to seizures, dementia, loss of vision and intracranial hemorrhage. Historically, surgical obliteration was...

First case in China: Onyx for bronchial artery embolization in treatment of refractory massive hemoptysis in one case.

Massive hemoptysis is a severe, life-threatening illness. Bronchial artery embolization is commonly used to treat massive hemoptysis. In May 2012, we first used a new liquid embolic agent (Onyx) for bronchial artery embolization in treatment of refractory massive hemoptysis in one patient in China and obtained good outcomes. The patient did not experience hemoptysis during a 10-month follow-up.

Le modafinil améliore les performances de conduite simulée des malades souffrant d’hypersomnie : étude randomisée placebo-verum

To report a novel technique for temporary and permanent vessel occlusion with a single microcatheter and investigate its efficacy in endovascular management of cerebral aneurysms and invasive head and neck tumors.A 58-year-old woman with a history of T3N0 squamous cell carcinoma of the tongue with extensive surgical resections and radiotherapy presented to the emergency department with further wound dehiscence and exposure of the left cervical internal carotid artery (ICA). Digital subtraction angiography (DSA) was performed with the patient under conscious sedation. An Ascent balloon, 4 mm × 15 mm, was prepared and introduced into the proximal ICA. While the patient was fully awake, temporary balloon occlusion (TBO) was performed for 30 minutes. The Ascent balloon was kept inflated. Through the inflated Ascent balloon, coil embolization of the proximal ICA was initiated. The interstices of the coils were filled with Onyx 18 and Onyx 34 liquid embolic agents (ev3 Neurovascular, Inc, Irvine, California, USA).The Ascent balloon can be used as a temporary balloon device and as a coil or Onyx embolization device. As a result, fewer catheters, guidewires, and balloon inflations and deflations are required for the procedure, which is both cost-effective and time-efficient. The combination of initial coiling to create a framework for the deconstruction with a liquid embolic agent (Onyx) is a safe and efficient technique for vessel deconstruction. Flow arrest with proximal balloon occlusion minimizes the risks of distal thromboembolic events during embolization.This novel technique for temporary and permanent vessel occlusion with a single microcatheter is both cost-effective and time-efficient.

Onyx embolization of anterior condylar confluence dural arteriovenous fistula

The anterior condylar confluence (ACC) is a small complex venous structure located medial to the jugular vein and adjacent to the hypoglossal canal. To our knowledge, this is the first...

Transarterial Embolization of Type II Endoleaks after EVAR: The Role of Ethylene Vinyl Alcohol Copolymer (Onyx)

To determine the feasibility and efficacy of transarterial endoleak embolization using the liquid embolic agent ethylene vinyl alcohol copolymer (Onyx). Over a 7-year period eleven patients (6 women, 5 men; mean age 68 years, range 37-83 years) underwent transarterial embolization of a type II endoleak after endovascular aortic aneurysm repair using the liquid embolic agent Onyx. Two patients (18 %) had a simple type II endoleak with only one artery in communication with the aneurysm sac, whereas 9 patients (82 %) had a complex type II endoleak with multiple communicating vessels. We retrospectively analyzed the technical and clinical success of transarterial type II endoleak embolization with Onyx. Complete embolization of the nidus was defined as technical success. Embolization was considered clinically successful when volume of the aneurysm sac was stable or decreased on follow-up CT scans. Mean follow-up time was 26.0 (range 6-50) months. Clinical success was achieved in 8 of 11 patients (73 %). Transarterial nidus embolization with Onyx was technically successful in 6 of 11 patients (55 %). In three cases the nidus was embolized without direct catheterization from a more distal access through the network of collateral vessels. Onyx is a favorable embolic agent for transarterial endoleak embolization. To achieve the best clinical results, complete occlusion of the nidus is mandatory.