Onyx Migration Research Articles

Long-term outcome of endovascular treatment for indirect carotid-cavernous fistulas.

Endovascular treatment (EVT) is the primary approach used to treat indirect carotid-cavernous fistulas (CCFs). In this study, the authors evaluated the immediate and long-term efficacy and safety of different endovascular techniques for indirect CCFs. The databases of two endovascular centers were retrospectively reviewed to collect the patients with indirect CCFs treated using endovascular techniques between 2013 and 2023. Demographics, clinical presentation, CCF features, EVT characteristics, and clinical and radiological outcomes were evaluated and analyzed. The analysis was performed to compare the clinical and radiological data between different endovascular approaches and different embolic materials. Ninety-eight patients were included in the study. EVT was successful in 95 patients (96.9%). Immediate complete obliteration of the CCF was achieved in 93.9% of patients, with 98% undergoing embolization with liquid embolic agents (LEAs) and 95.6% undergoing coiling alone. Complete CCF obliteration was higher in the transvenous than in the transarterial approach (94.3% vs 75%, p = 0.010). At ≥ 6 months follow-up, complete CCF obliteration was achieved in all patients (100%). The rate of procedure-related complications was higher following LEAs than with coiling alone (32.0% vs 15.6%). New cranial nerve (CN) palsy was diagnosed in 26.0% and 2.2% after embolization with LEAs and coiling alone, respectively (p = 0.001), with complete CN palsy recovery in 78.6%. Procedure-related intracranial hemorrhage occurred in 3 patients (3.1%). Two patients experienced an ischemic stroke following Onyx migration into the internal carotid artery. Ocular symptoms improved in 93% (83/89) of the patients who were followed. In this study, complete obliteration of an indirect CCF was achieved in more than 90% of patients. Despite the occurrence of some new postprocedural ocular CN palsy, ocular symptoms improved in most patients in long-term follow-up. The transvenous approach was the most effective method for treating the indirect CCF. Coiling was safer than LEAs for the embolization of the indirect CCF.

Technical video: Onyx-18 embolization of spinal epidural arteriovenous Fistula using the scepter-Mini balloon catheter.

Spinal arteriovenous fistulas (AVFs) account for approximately 70% of all vascular spinal malformations and commonly develop in the lateral epidural space at the epidural /radicular venous junction. The fistula is located close to the spinal nerve root where a radiculomeningeal artery shunts to a radicular vein. Increased venous pressure leads to decreased spinal venous drainage and venous congestion causing progressive myelopathy, bowel/bladder incontinence and erectile dysfunction. Treatment consists of surgical occlusion of the intradural vein, or endovascular embolization, which has a reported success rate of 25%-75%.1 Endovascular failure can occur with inadequate embolic penetration of the nidus and the proximal segment of the draining vein, or premature reflux of the liquid embolic agent.The use of a dual-lumen balloon microcatheter offers advantage in these cases given the ability to push liquid embolysate more distally during balloon inflation. The Scepter Mini is a new dimethyl-sulfoxide (DMSO)-compatible dual-lumen balloon microcatheter with a distal-tip outer diameter of 1.6 Fr and a nominal balloon diameter of 2.2 mm, facilitating atraumatic navigation and safer balloon inflation. Limited neurointerventional experience using the Scepter Mini in predominantly cerebrovascular cases has reported favorable navigability and flow arrest2, 3 Although Onyx is rarely used for spinal AVF embolization, success has been reported considering the well-known favorable experience in cerebral cases.1, 4, 5We present one of the first cases of Onyx embolization of a spinal dural AVF through a Scepter Mini in a patient with progressively worsening lower extremity sensorimotor dysfunction. Operators should be aware of radiculomedullary arteries arising at the same level or at adjacent levels to avoid unintentional Onyx migration during balloon inflation.

Utility of manual venous compression during transvenous Onyx injection for a scalp arteriovenous fistula: illustrative case.

When performing transvenous liquid embolization for scalp arteriovenous fistulas, multiple networks of venous drainage could limit effective retrograde penetration of embolic agents into feeding arteries, resulting in incomplete obliteration. A salvage technique to achieve effective Onyx penetration with manual venous compression during transvenous embolization is demonstrated. A 43-year-old man presented with a progressively enlarging mass on his left temporal scalp that was first noticed approximately 20 years earlier. External carotid artery injection showed two scalp arteriovenous fistulas (AVFs). The patient received endovascular embolization. After successful transarterial obliteration of one AVF, transvenous Onyx embolization was performed for another AVF located in the subcutaneous layer. To avoid unnecessary Onyx migration into multiple venous networks, several coils were put in a venous pouch as a scaffold for the Onyx, and feeding arteries were temporarily occluded. Despite these adjunctive techniques, the Onyx migrated into multiple veins and even toward the orbit without complete fistula obliteration. Thereafter, Onyx was injected under manual compression of venous outlets from the pouch, resulting in complete obliteration. Manual compression of venous outlets can be used as a salvage procedure during transvenous Onyx embolization for a scalp AVF. A surgeon's radiation exposure can be reduced by step-by-step adjunctive procedures.

A Case of Occlusion of the Contralateral Posterior Cerebral Artery Caused by the Migration of Onyx during Embolization of Cerebral Arteriovenous Malformation and Successful Recanalization Therapy Using a Stent Retriever

A Case of Occlusion of the Contralateral Posterior Cerebral Artery Caused by the Migration of Onyx during Embolization of Cerebral Arteriovenous Malformation and Successful Recanalization Therapy Using a Stent Retriever

Onyx Migration Into the Anterior Spinal Artery During Lumbar Artery Embolisation: an Adverse Event

IntroductionThe impact of sequential lumbar and intercostal artery occlusion on the risk of spinal cord ischaemia was evaluated; however, an adverse event (paraplegia) was encountered, which resulted in study interruption. Investigations were carried out to understand the reasons for the paraplegia.ReportTo develop a porcine model of spinal cord ischaemic preconditioning prior to extensive thoraco-abdominal aneurysm endovascular aortic repair, the lumbar arteries were selectively embolised with Onyx 5 days prior to an extended thoracic aortic stent graft. Six pigs were used in this preliminary work. Four cases of paraplegia secondary to accidental migration of Onyx to the anterior spinal artery from the lumbar arteries are reported. Histological analysis confirmed severe spinal ischaemic injury and the presence of Onyx particles in the anterior spinal artery.DiscussionOnyx is used for lumbar artery embolisation in type II endoleak treatment after endovascular aortic repair, and while migration in lumbar arteries is frequent, the risk of spinal cord ischaemia has never been described. The current study demonstrates the risk of paraplegia following Onyx migration to the anterior spinal artery from the lumbar artery in an experimental model. Thus, Onyx treatment for type II endoleaks from lumbar arteries should be used cautiously.

Initial experience with dual-lumen balloon catheter injection for preoperative Onyx embolization of skull base paragangliomas.

OBJECT Paragangliomas are highly vascular head and neck tumors for which preoperative embolization is often considered to facilitate resection. The authors evaluated their initial experience using a dual-lumen balloon to facilitate preoperative embolization in 5 consecutive patients who underwent preoperative transarterial Onyx embolization assisted by the Scepter dual-lumen balloon catheter between 2012 and 2014. OBJECT The authors reviewed the demographic and clinical records of 5 patients who underwent Scepter-assisted Onyx embolization of a paraganglioma followed by resection between 2012 and 2014. Descriptive statistics of clinical outcomes were assessed. RESULTS Five patients (4 with a jugular and 1 with a vagal paraganglioma) were identified. Three paragangliomas were embolized in a single session, and each of the other 2 were completed in 3 staged sessions. The mean volume of Onyx used was 14.3 ml (range 6-30 ml). Twenty-seven vessels were selectively catheterized for embolization. All patients required selective embolization via multiple vessels. Two patients required sacrifice of parent vessels (1 petrocavernous internal carotid artery and 1 vertebral artery) after successful balloon test occlusion. One patient underwent embolization with Onyx-18 alone, 2 with Onyx-34 alone, and 1 with Onyx-18 and -34. In each case, migration of Onyx was achieved within the tumor parenchyma. The mean time between embolization and resection was 3.8 days (range 1-8 days). Gross-total resection was achieved in 3 (60%) patients, and the other 2 patients had minimal residual tumor. The mean estimated blood loss during the resections was 556 ml (range 200-850 ml). The mean postoperative hematocrit level change was -17.3%. Two patients required blood transfusions. One patient, who underwent extensive tumor penetration with Onyx, developed a temporary partial cranial nerve VII palsy that resolved to House-Brackmann Grade I (out of VI) at the 6-month follow-up. One patient experienced improvement in existing facial nerve weakness after embolization. CONCLUSIONS Scepter catheter-based Onyx embolization seems to be safe and effective. It was associated with excellent distal tumor vasculature penetration and holds promise as an adjunct to conventional transarterial Onyx embolization of paragangliomas. However, the ease of tumor penetration should encourage caution in practitioners who may be able to effect comparable improvement in blood loss with more conservative proximal Onyx penetration.

Endovascular Treatment of Dural Arteriovenous Fistulas: Single Center Experience.

ObjectiveTreatment of intracranial dural arteriovenous fistulas (dAVFs) remains a challenge. However, after introduction of Onyx, transarterial approach is the preferred treatment option in many centers. We report our experience of dAVFs embolization with special emphasis on transarterial approach.MethodsSeventeen embolization procedures were performed in 13 patients with dAVFs between Jan 2009 and Oct 2014. Clinical symptoms, location and type of fistulas, embolization methods, complications, radiological and clinical outcomes were evaluated using charts and PACS images.ResultsAll 13 patients had symptomatic lesions. The locations of fistulas were transverse-sigmoid sinus in 6, middle fossa dura in 4, cavernous sinus in 2, and superior sagittal sinus in 1 patient. Cognard types were as follows : I in 4, IIa in 2, IIa+IIb in 5, and IV in 2. Embolization procedures were performed ≥2 times in 3 patients. Nine patients were treated with transarterial Onyx embolization alone. One of these required direct surgical puncture of middle meningeal artery. Complete obliteration of fistulas was achieved in 11/13 (85%) patients. There were no complications except for 1 case of Onyx migration in cavernous dAVF. Modified Rankin scale score at post-operative 3 months were 0 in 11, and 3 in 2 patients.ConclusionTransarterial Onyx embolization can be a first line therapeutic option in patients with dAVFs. However, transvenous approach should be tried first in cavernous sinus dAVF because of the risk of intracranial migration of liquid embolic materials. Furthermore, combined surgical endovascular approach can be considered as a useful option in inaccessible route.

Carotid and vertebral artery sacrifice with a combination of Onyx and coils: technical note and case series

Permanent vessel sacrifice has become a routine for the management of aneurysms, pseudoaneurysms, tumors, and carotid blowouts. The purpose of this study is to describe a new technique for carotid and vertebral artery sacrifice using a combination of Onyx and coils and to assess its feasibility, safety, and efficacy. The technique consists of deploying a few coils in the parent vessel under proximal flow arrest followed by Onyx embolization directly into the coil mass. A total of 41 patients underwent carotid/vertebral artery sacrifice using this technique in our institution. A total of 26 internal carotid arteries and 15 vertebral arteries were treated. In all but one patient, a balloon test occlusion was performed prior to permanent arterial sacrifice. The mean number of coils used was 6.8 (range, 2-19). The total volume of Onyx used was 1.3 ml on average (range, 0.2-5.2 ml). All 41 (100%) parent arteries were successfully occluded. No distal migration of Onyx or coils was noted. Periprocedural complications occurred in 14.6% (6/41) of cases causing permanent morbidity in 7.3% (3/41). No patient developed a recurrence during the follow-up period (mean, 14 months). Parent vessel sacrifice with a combination of Onyx and coils appears to be feasible, safe, and effective and may be an alternative to the traditional deconstruction technique with coils alone. The risk of thromboembolism exists with this technique, but there were no instances of Onyx migration.

Abstract WMP26: Endovascular Arterial Deconstruction with a Combination of Onyx and Coils: Technique, Feasibility, and Complications

Object: Permanent vessel deconstruction has become routine for the management of aneurysms, pseudoaneurysms, tumors, and carotid blowouts. We describe a new technique for carotid and vertebral artery deconstruction using a combination of Onyx and coils, and assess its feasibility, safety, and efficacy. Methods: Between 2008 and 2012, a total of 41 patients underwent carotid or vertebral artery deconstruction with a combination of Onyx and coils in our institution. A few coils were initially deployed in the parent vessel under proximal flow arrest followed by Onyx embolization directly into the coil mass. Results: A total of 26 internal carotid arteries and 15 vertebral arteries were treated. In all but one patient, a balloon test occlusion was performed prior to permanent arterial occlusion. The mean number of coils used was only 6.8 (range, 2-19). The total volume of Onyx used was 1.3 ml on average (range, 0.2-5.2 ml). All 41 (100%) parent arteries were successfully occluded. No distal migration of Onyx or coils was noted. Periprocedural complications occurred in 14.6% (6/41) of cases causing permanent morbidity in 7.3% (3/41). All were the result of delayed ischemic events after vessel deconstruction; none were related to the occlusion technique. No patient developed a recurrence during the follow-up period (mean, 14 months). Conclusions: Parent vessel occlusion with a combination of Onyx and coils is feasible, safe, and effective and results in significant savings in terms of cost, operative time, and fluoroscopy time. Importantly, no complications related to the technique itself were encountered in the series. This new technique should replace the traditional deconstruction technique with coils alone.

Flow control techniques for Onyx embolization of intracranial dural arteriovenous fistulae

ObjectivesExperience of flow control techniques during endovascular treatment of intracranial dural arteriovenous fistulas (DAVFs) using the Onyx liquid embolic system is reported, with an emphasis on high flow shunts.MethodsData were...

Endovascular Treatment of Acute Arterial Hemorrhage in Trauma Patients Using Ethylene Vinyl Alcohol Copolymer (Onyx)

This study was designed to determine the feasibility and efficacy of endovascular embolization with liquid embolic agent ethylene vinyl alcohol copolymer (Onyx) in patients with acute traumatic arterial bleeding. This is a retrospective review of 13 patients (9 men and 4 women; mean age 45years) with severe trauma who underwent embolotherapy using Onyx from November 2003 to February 2009. Bleeding was located in the pelvis (5 patients), kidney (3 patients), mesenteric region (2 patients), retroperitoneal space (2 patients), neck (1 patient), and thigh (1 patient). In three cases (23.1%), Onyx was used in conjunction with coils. We evaluate the technical and clinical success, procedural and embolization time, occurrence of rebleeding, and embolotherapy-related complications, such as necrosis or migration of Onyx into nontarget vessels. In all patients, embolotherapy was technically and clinically successful on the first attempt. Control of bleeding could be reached with a mean time of 19 (range, 4-63)min after correct placement of the microcatheter in the feeding artery. No recurrent bleeding was detected. No unintended necrosis or migration of Onyx into a nontarget region was observed. During the follow-up period, three patients (23.1%) died due to severe intracranial hemorrhage, cardiac arrest, and sepsis. Transcatheter embolization with new liquid embolic agent Onyx is technically feasible and effective in trauma patients with acute arterial hemorrhage.

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

Embolization of grade III-V intracranial DAVFs using Onyx is feasible with promising results, indicating stability at the time of mid-term follow-up. This article is to evaluate the role of transarterial Onyx embolization in the treatment of grade I and II intracranial dural arteriovenous fistulas (DAVFs), including its limitations and risks. We retrospectively studied consecutive 26 patients (8 women and 18 men) treated for an grade I and II intracranial DAVF since 2006 in whom a transarterial approach was attempted with Onyx-18 embolization. There were 18 transverse-sigmoid sinus, 4 cavernous sinus, 2 superior sagittal sinus, 1 inferior petrosal sinus and 1 intradiploic fistulas. Five fistulas were Type I, 8 were Type IIa, and 13 were Type IIa+b, according to the Cognard classification. The mean clinical follow-up period was 15.6 months. Anatomic cure was proven in 13 patients (50%) and clinical cure was obtained in 17 cases (65.4%). These 13 cures were achieved after a single procedure. All these 13 patients underwent a follow-up angiography, which has confirmed the complete cure. Partial occlusion was obtained in 13 patients. Complications were as follows: 2 cardiac Onyx migration, 2 reflexive bradyarrythmia, 1 transient visual hallucination, 2 transient fifth nerve palsies and 1 permanent seventh nerve palsy in inferior petrosal sinus DAVF. Based on this experience, grade I and II intracranial DAVFs may be treated with transarterial Onyx embolization to reduce the shunted blood flow and to facilitate subsequent transvenous embolization or surgery.

Onyx Migration in the Endovascular Management of Intracranial Dural Arteriovenous Fistulas

Onyx migration in the endovascular treatment of dural arteriovenous fistulas (dural AVFs) is uncommon. We describe five cases of Onyx migration to the heart and draining vein and its avoidance. Between February 2007 and August 2008, Onyx migration was encountered in five patients with dural AVFs treated endovascularly at our institute. Procedures performed under general anesthesia consisted of two arterial approaches and three venous approaches. Two patients with dural AVFs involving the transverse-sigmoid sinus were treated by transarterial embolization using Onyx-18 via the occipital artery and the posterior branch of the middle meningeal artery, respectively. A piece of Onyx was found in the right ventricle on post-embolization chest X-ray film in both patients, one developed tricuspid valve dysfunction requiring thoracic surgery and one was asymptomatic. The other three patients were treated with a combination of Onyx (34 or 18) and coils transvenously with venous Onyx migration leading to draining vein occlusion, one with dural AVF involving the tentorium died from venous rupture, two patients with bilateral dural AVFs of the cavernous sinus (one with deterioration of ocular symptoms and one without symptoms). Postoperative digital subtraction angiography confirmed the elimination of dural AVF in one patient, and residual fistulae in three patients. The follow-up study ranging from two to nine months (average, 4.5 months). Three patients recovered to their full activities, while one had visual disturbance. Although Onyx has been considered a controllable embolic agent, its migration to other locations causing clinical deterioration can occur. This problem should be noted and prevented.

Complications Related to Percutaneous Transarterial Embolization of Intracranial Dural Arteriovenous Fistulas in 40 Patients

An increasing number of intracranial dural arteriovenous fistulas (DAVFs) are amenable to endovascular treatment with Onyx. However, reports on complications caused by this technique have been limited. We present the initial Beijing Tiantan Hospital experience with adverse events related to transarterial Onyx embolization for DAVFs. Between September 2005 and February 2008, a total of 40 patients with DAVFs were treated at our institute with Onyx-18. There were 11 women and 29 men with a mean age of 43.15 years (age range, 23-60 years). We reviewed the clinical presentation, angiographic features, treatment, and outcome. In 40 patients, total obliteration was achieved in 25 DAVFs (62.5%), with the remaining 15 patients not cured with residual shunts. Complications occurred in 9 patients, 5 DAVFs were located at tentorium, 2 were located at the transverse-sigmoid sinus, 1 was found at the inferior petrosal sinus, and 1 was found at the cavernous sinus, leading to permanent disability in 3 patients (morbidity, 7.5%). Complications included reflexive bradyarrhythmia in 3 (7.5%) patients, hemifacial hypoesthesia in 3 (7.5%) patients, hemifacial palsy in 2 (5%) patients, posterior fossa infarction in 2 (5%) patients, jaw pain in 1 (2.5%) patient, microcatheter gluing in 1 (2.5%) patient, hallucinations in 1 (2.5%) patient, and Onyx migration in 1 (2.5%) patient. Although complete cure can be achieved by transarterial embolization with Onyx, the potential for serious complications exists with this procedure.

Onyx in an experimental aneurysm model: histological and angiographic results

The use of liquid embolic agents for endovascular treatment of cerebral aneurysms is evolving. The authors' aim was to evaluate the use of Onyx HD-500 in an experimental aneurysm model and to obtain histological and angiographic long-term results. Ten aneurysms were created using an elastase model in rabbits. The aneurysms were embolized using Onyx in combination with an inflated balloon. One animal died 1 day after embolization. The animals were divided into 2 different groups. The animals in the first group (4 rabbits) were killed at 3 months and those in the second group (5 rabbits) were killed at 6 months after embolization. A venous control angiogram was obtained, and the aneurysms were examined histologically. In both groups control angiograms demonstrated that all aneurysms were completely occluded. There were no signs of recanalization. Migration of Onyx was seen in 4 animals, leading to the death of 1. Histological examination not only proved the aneurysms to be occluded but also demonstrated a thin layer of endothelium at the neck of the aneurysm. The histological result was identical in both groups. This is the first study reporting the formation of a neointima over the neck of aneurysms embolized with Onyx in a rabbit model. Although the technique is challenging and migration of the liquid embolic agent cannot always be prevented, Onyx has a great potential to achieve a durable occlusion of aneurysms.

Endovascular Treatment of Cerebral Aneurysm with Coils and Onyx. in-vivo experiment.

We investigated endovascular treatment of cerebral aneurysm by coil and Onyx in vivo experiment in order to promote the advantages of coil embolization,. The aim of this study was to clarify the advantages and problems of coil and Onyx embolization and to evaluate its potentials for application in clinical medicine. We set experimental aneurysms made of external jugular vein to bilateral carotid arteries of 10 Beagle dogs and embolized aneurysm with coils and Onyx.Two months later, the dogs were sacrificed and took out the experimental aneurysms and examined them histologically. We have experienced Onyx migration into the vessel at the beginning of our experiment. Technical problems were as follows; Onyx was not easily visible on DSA monitor particularly in tight coil packing. Catheter tip was often stuck to the Onyx in the aneurysm. Protect balloon could not completely protect the Onyx leakage into the vessel. Microscopic examinations were as follows; The aneurysm was filled with Onyx, coils, and inflammatory reactants. The orifice of the aneurysm was packed with augmented fibrous tissue. 1. This method increased contact between the aneurysm wall and coils. 2. Onyx filled the intra-aneurismal space more tightly. 3. Coils prevented Onyx from flowing out into the vessel. 4. In Onyx, intimal layer was more rapidly formed at the neck of the aneurysm than coils only. 5. The most important problems during Onyx embolization is how to prevent Onyx migration into the vessel. We should like to propose the guideline for Onyx embolization.