Spinal tumor embolization with Onyx: A systematic review and meta-analysis

INTRODUCTION

Onyx embolization has emerged as a promising technique for spinal tumor embolization due to its high devascularization rate and low incidence of complications.

OBJECTIVE

Evaluate the safety and efficacy of Onyx embolization in spinal tumor procedures.

METHODS

Following the PRISMA guidelines, we conducted a systematic review and meta-analysis. To be included, the articles had to report specific outcomes of Onyx embolization for spinal tumors (complications, mortality, blood loss, tumor devascularization, or reduction in tumor blush).

RESULTS

We selected 11 out of 2941 articles, encompassing 127 patients. Among them, no major complications or persistent neurological deficits were reported, and no deaths occurred as a result of the embolization procedure. Of the 63 patients with available data, two complications were observed: one infarct leading to transient neurological deficit and one clinically silent vessel perforation related to the microcatheter. Thus, the complication rate was 1% (95% confidence interval (CI): 0% to 6%). Blood loss during surgery ranged from 100 to 1500 mL (four studies). Complete tumor blush reduction was achieved in 52% of the cases (95% CI: 16% to 88%) across 32 patients. Three studies reported a median percentage of tumor devascularization of 91% (86.1% to 97.5%).

CONCLUSION

Onyx embolization for spinal tumor procedures appears to be a safe technique, as evidenced by the absence of major complications or deaths. However, the determination of its efficacy remains challenging due to limited data availability and substantial heterogeneity across studies. These findings highlight the need for future research to address this knowledge gap and further validate our results.

Refinement of nBCA embolization technique in treatment of metastatic spinal tumors: Case series and technical report

BACKGROUND AND OBJECTIVES

Preoperative embolization of metastatic spinal tumors (MSTs) has proven advantageous in limiting intraoperative blood loss (IBL) during resection. N-butyl cyanoacrylate (nBCA) is a liquid embolic agent known for its rapid hemostatic effects. However, nBCA is associated with a higher risk of distal nontarget embolization. This study highlights the refinement of the embolization technique and assesses its efficacy in performing an initial distal segmental artery plug with concentrated nBCA followed by proximal diluted nBCA for MSTs.

METHODS

A retrospective review of patients with MST (2018-2023) was performed. Patients who underwent preoperative nBCA endovascular embolization prior to tumor resection and spinal instrumentation were included. Baseline standard spinal angiography was performed.

RESULTS

Sixteen patients (13 men, 3 women; 56.0 ± 12.4 years) met inclusion criteria. And 43.75% (7 of 16) had thoracic levels, 37.5% (6 of 16) lumbar, and 18.75% (3 of 16) sacral. The most common primary tumor was renal cell carcinoma (43.75%, 7 of 16). A total of 43 pedicles were embolized (median 3), resulting in complete/near complete obliteration of the tumor blush. Most pedicles (83.7%, 36 of 43) received a single dilute concentration of nBCA; however, 16.3% (7 of 43) received two separate concentrations of nBCA, a denser concentration distally into the segmental artery and a diluted concentration proximally into the tumor bed. Mean IBL was 1150 ± 1201 mL in 3 distal plug patients distal plug patients versus 1625 ± 681 mL in 12 other patients. There were no complications related to embolization.

CONCLUSION

Performing a distal, concentrated nBCA plug during preoperative nBCA embolization of MSTs may increase tumor penetration and reduce IBL.

Assessing the efficacy and safety of hemangioblastoma embolization: A comprehensive systematic review and meta-analysis

BACKGROUND

Hemangioblastomas (HBs) are highly vascular tumors linked to substantial morbidity and mortality. Recently, interventional neuroradiology has evolved rapidly, spurring interest in preoperative embolization as a possible HB treatment.

PURPOSE

This study evaluates the effectiveness and safety of preoperative embolization in managing HB.

METHODS

Adhering to PRISMA guidelines, this meta-analysis considered randomized and nonrandomized studies meeting specific criteria, encompassing intracranial HB and preoperative embolization. Primary outcomes were preoperative embolization efficacy and safety. Complications were classified as major (cerebellar ischemia, ischemic strokes, intratumoral hemorrhage, subarachnoid hemorrhage) and minor (transient nystagmus, slight facial nerve palsy, nausea, transient dysarthria, hemiparesis, hemisensory impairment, thrombotic complications, extravasation).

RESULTS

Thirteen studies involving 166 patients with preoperative embolization before HB resection were included. Two studies using the Glasgow Outcome Scale (GOS) showed 5 patients with good recovery, 6 with moderate disability, and 3 with severe disability. Major complications occurred in 1% (95% CI: 0% to 3%), and minor complications occurred in 1% (95% CI: 0% to 4%). Intraoperative blood loss during resection was estimated at 464.29 ml (95% CI: 350.63 ml to 614.80 ml).

CONCLUSION

Preoperative embolization holds promise in reducing intraoperative bleeding risk in neurosurgical intracranial HB treatment, primarily due to its low complication rates. Nonetheless, additional research and larger-scale studies are essential to establish its long-term efficacy and safety. These findings highlight preoperative embolization as a valuable tool for HB management, potentially enhancing future patient outcomes.

Liquid Embolic Agents for Endovascular Embolization: A Review

Endovascular embolization (EE) has been used for the treatment of blood vessel abnormalities, including aneurysms, AVMs, tumors, etc. The aim of this process is to occlude the affected vessel using biocompatible embolic agents. Two types of embolic agents, solid and liquid, are used for endovascular embolization. Liquid embolic agents are usually injectable and delivered into the vascular malformation sites using a catheter guided by X-ray imaging (i.e., angiography). After injection, the liquid embolic agent transforms into a solid implant in situ based on a variety of mechanisms, including polymerization, precipitation, and cross-linking, through ionic or thermal process. Until now, several polymers have been designed successfully for the development of liquid embolic agents. Both natural and synthetic polymers have been used for this purpose. In this review, we discuss embolization procedures with liquid embolic agents in different clinical applications, as well as in pre-clinical research studies.

Imaging diagnosis and the role of endovascular embolization treatment for vascular intraspinal tumors

Intraspinal tumors comprise a large spectrum of neoplasms, including hemangioblastomas, paragangliomas, and meningiomas. These tumors have several common characteristic imaging features, such as highly vascular mass appearance in angiography, hypointense rim and serpentine flow voids in MRI, and intense enhancement after intravenous contrast administration. Due to their rich vascularity, these tumors represent a special challenge for surgical treatment. More recently, the surgical treatment of intraspinal vascular tumors has benefited from the combination of endovascular techniques used to better delineate these lesions and to promote preoperative reduction of volume and tissue blood flow. Endovascular embolization has been proven to be a safe procedure that facilitates the resection of these tumors; hence, it has been proposed as part of the standard of care in their management.

Incidence of cranial nerve palsy after preoperative embolization of glomus jugulare tumors using Onyx

OBJECT

The resection of glomus jugulare tumors can be challenging because of their inherent vascularity. Preoperative embolization has been advocated as a means of reducing operative times, blood loss, and surgical complications. However, the incidence of cranial neuropathy associated with the embolization of these tumors has not been established. The authors of this study describe their experience with cranial neuropathy following transarterial embolization of glomus jugulare tumors using ethylene vinyl alcohol (Onyx, eV3 Inc.).

METHODS

The authors retrospectively reviewed all cases of glomus jugulare tumors that had been treated with preoperative embolization using Onyx at their institution in the period from 2006 to 2012. Patient demographics, clinical presentation, grade and amount of Onyx used, degree of angiographic devascularization, and procedural complications were recorded.

RESULTS

Over a 6-year period, 11 patients with glomus jugulare tumors underwent preoperative embolization with Onyx. All embolization procedures were completed in one session. The overall mean percent of tumor devascularization was 90.7%. No evidence of nontarget embolization was seen on postembolization angiograms. There were 2 cases (18%) of permanent cranial neuropathy attributed to the embolization procedures (facial nerve paralysis and lower cranial nerve dysfunction).

CONCLUSION

Embolizing glomus jugulare tumors with Onyx can produce a dramatic reduction in tumor vascularity. However, the intimate anatomical relationship and overlapping blood supply between these tumors and cranial nerves may contribute to a high incidence of cranial neuropathy following Onyx embolization.

Onyx injection by direct puncture for the treatment of hypervascular spinal metastases close to the anterior spinal artery: initial experience

Presurgical devascularization of hypervascular spinal metastases has been shown to be effective in preventing major blood loss during open surgery. Most often, embolization can be performed using polyvinyl alcohol (PVA) microparticles. However, in some cases, the close relationship between the feeders of the metastases and the feeders of the anterior spinal artery (ASA) poses a risk of spinal cord ischemia when PVA microparticle embolization is performed. The authors present their early experience in the treatment of spinal metastases close to the ASA; in 2 cases they injected Onyx-18, by direct puncture, into hypervascular posterior arch spinal metastases situated close to the ASA. Two women, one 36 and the other 55 years of age, who presented with spinal lesions (at the posterior arch of C-4 and T-6, respectively) from thyroid and a kidney tumors, were sent to the authors' department to undergo presurgical embolization. After having performed a complete spinal digital subtraction angiography study, a regular angiography catheter was positioned at the ostium of the artery that mainly supplied the lesion. Then, with the patient in the left lateral decubitus position, direct puncture with 18-gauge needles of the lesion was performed using roadmap guidance. Onyx-18 was injected through the needles under biplanar fluoroscopy. Satisfactory devascularization of the lesions was obtained; the ASA remained patent in both cases. The metastases were surgically removed in both cases within the 48 hours after the embolization and major blood loss did not occur. Presurgical devascularization of hypervascular spinal metastases close the ASA by direct puncture with Onyx-18 seems to be an effective technique and appears to be safe in terms of the preserving the ASA's patency.

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.

Transfemoral Transarterial Onyx Embolization of Carotid Body Paragangliomas

BACKGROUND:

The association of carotid body paragangliomas with neurovascular structures can cause cranial nerve injury and significant intraoperative blood loss. Preoperative embolization may be performed either percutaneously or transarterially.

OBJECTIVE:

We reviewed our experience with transfemoral transarterial Onyx embolization.

METHODS:

We retrospectively reviewed a prospectively maintained database of head and neck tumors embolized between November 2007 and February 2012. Patients were assessed for number of sessions of embolization, number of pedicles embolized, fluoroscopic time, extent of tumor devascularization as assessed by postembolization angiography, and operative blood loss.

RESULTS:

Eleven patients (5 men, 6 women; mean age, 48.1 years) with 13 paragangliomas (5 right-sided, 9 left-sided, 2 bilateral) underwent preoperative embolization for 12 tumors. Onyx alone was used in 9 cases. In a mean of 1.2 embolization sessions (range, 1–2), an average of 2.8 pedicles (range, 1–7) was embolized. The average fluoroscopic time was 54.3 minutes. In 5 cases, the tumors were completely devascularized by using this strategy. In 5 cases, more than 90% tumor devascularization was achieved. In the remaining 2 cases, tumor devascularization was more than 50%. A partial cranial nerve XII palsy was the only postprocedural complication. The mean surgical blood loss was 191.7 mL (range, 25–600 mL).

CONCLUSION:

The arterial supply to carotid body tumors can be catheterized effectively through a transfemoral approach, permitting embolization of feeding pedicles. Transarterial Onyx embolization of these lesions is safe and effective, and it decreases blood loss during surgical resection.

Onyx pulmonary artery embolization after treatment of a low-flow dural arteriovenous fistula: case report

BACKGROUND AND IMPORTANCE

Endovascular management of dural arteriovenous fistulas (DAVFs) has become an accepted primary and often definitive therapy. We present the first documented case of Onyx pulmonary embolism after embolization of a low-flow DAVF.

CLINICAL PRESENTATION

A 63-year-old man presented with subarachnoid hemorrhage secondary to a DAVF. Computed tomographic angiography, magnetic resonance imaging, and initial conventional angiogram were negative. A repeat angiogram demonstrated a DAVF, which was cured with Onyx embolization. A routine chest computed tomography after intervention revealed an asymptomatic Onyx embolization cast in a subsegmental pulmonary artery.

CONCLUSION

Endovascular treatment options include transarterial embolization with microcoils, polyvinyl alcohol particles, n-butyl-2cyanoacrylate, and Onyx (ev3 Neurovascular, Irvine, California). Complications associated with the use of Onyx are low but include embolizate pulmonary embolism. Patients often remain asymptomatic, but for symptomatic patients, conservative treatment options usually result in resolution of symptoms.

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.

Preoperative Onyx embolization of a giant cavernous malformation involving the dural sinuses

Cavernous malformations (CMs) or hemangiomas arising from within the dural sinuses are rare entities that differ from their parenchymal counterparts in that they are highly vascular lesions. While parenchymal CMs are typically angiographically occult, intrasinus malformations may have large, dural-based arterial feeding vessels that are amenable to preoperative embolization. The novel liquid embolic Onyx (ev3, Inc.) is an ideal agent for the embolization of these lesions. The authors present the first known case of a giant intrasinus CM embolized with Onyx before gross-total resection. The authors report the case of a 9-year-old boy with brief apneic episodes in whom MR imaging revealed a giant CM arising from within the right transverse and sigmoid sinuses and infiltrating the right tentorium cerebelli. At another institution, the patient had undergone 1 prior embolization and 2 unsuccessful attempts at resection. Both surgeries had been complicated by massive blood loss and were aborted. Under the authors' care, the patient underwent preoperative transarterial embolization with Onyx during which a substantial volume of the mass lesion was filled with embolisate. Subsequently, complete circumferential excision of the mass from the tentorium was accomplished with minimal intraoperative blood loss.