Intra-arterial Onyx Embolization of Vertebral Body Lesions

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.

Transpedicular Onyx embolization of a thoracic hemangioma with robotic assistance: illustrative case

BACKGROUND

Hemangiomas are common benign vascular lesions that rarely present with pain and neurological deficits. Symptomatic lesions are often treated with endovascular embolization. However, transarterial embolization can be technically challenging depending on the size and caliber of the vessels. Moreover, embolization can result in osteonecrosis and vertebral collapse.

OBSERVATIONS

Here the authors report the first case of a T10 vertebral hemangioma treated with transpedicular Onyx embolization aided by a robotic platform that guided pedicle cannulation and Craig needle placement. An intravenous catheter was attached to the needle and dimethylsulfoxide was infused, followed by Onyx under real-time fluoroscopy. Repeat angiography demonstrated significantly reduced contrast opacification of the vertebral body without compromise of the segmental artery. A T9-11 pedicle screw fixation was performed to optimize long-term stability. The patient's symptoms improved and was stable at the 6-month follow-up.

LESSONS

Transpedicular embolization of vertebral hemangiomas can be performed successfully under robotic navigation guidance, avoiding complications seen with the intra-arterial approach and allowing for simultaneous pedicle screw fixation to prevent collapse and delayed kyphotic deformity. During the same procedure, a biopsy specimen can be collected for pathology. This technique can help to alleviate patient symptoms while avoiding complications associated with transarterial embolization or open resection.

In Vertebral Hemangiomas with Neurological Deficit, Is a Less Extensive Approach Adequate

STUDY DESIGN

This was a retrospective study.

PURPOSE

To analyze the surgical and neurological outcomes following surgical decompression in patients with aggressive vertebral hemangioma (AVH) presenting with neurological deficit and to determine whether a less extensive approach is appropriate.

OVERVIEW OF LITERATURE

AVHs are a rare subset of benign vascular tumors frequently presenting with neurological deficit because of spinal cord compression. Though the results of surgical management have improved over time, there is a lack of consensus on the ideal management in this group of patients.

METHODS

Twenty-one patients who underwent surgery for AVH between 2009 and 2018 were analyzed. Demographic and clinical details of patients were retrieved from hospital information system. Imaging information (i.e., radiography, computed tomography, magnetic resonance imaging) of all patients was accessed and analyzed in picture archiving and communication system. Tumor staging was performed using Enneking and Weinstein-Boriani-Biagini classifications and Spinal Instability Neoplastic Score. At followup, neurological and radiological evaluations were performed.

RESULTS

Twenty-one patients (13 [61.9%] females and 8 [38.1%] males) were included with a mean age of 44.29 years (range, 14-72 years). All patients in the study had neurological deficit. Back pain was present in 80.9% of patients. Mean duration of symptoms was 4.6 months (range, 1 day to 10 months). Most common lesion location was thoracic spine (n=12), followed by thoracolumbar (D11- L2; n=7) and lumbar (n=2) regions. Ten patients had multiple level lesions. All patients underwent preoperative embolization. Nine patients underwent intralesional spondylectomy with reconstruction; another nine patients underwent stabilization, decompression, and vertebroplasty; three patients underwent decompression and stabilization. Neurology improved in all patients, and only one case of recurrence was noted in a mean follow-up of 55.78±25 months (range, 24-96 months).

CONCLUSIONS

In AVH, good clinical and neurological outcomes with low recurrence rates can be achieved using less extensive procedures, such as posterior instrumented decompression with vertebroplasty and intralesional tumor resection.

Neurologic Complications of Preoperative Embolization of Spinal Metastasis: A Systemic Review of the Literature Identifying Distinct Mechanisms of Injury

BACKGROUND

Preoperative embolization of spinal metastases may improve outcomes of resection by reducing surgical blood loss and operative time. Neurologic complications are rarely reported and the mechanisms leading to injury are poorly described.

METHODS

We present 2 illustrative cases of embolization-related neurologic injury from distinct mechanisms and the findings of a systemic literature review of similar complications according to the PRISMA guidelines.

RESULTS

A 77-year-old man with a history of renal cell carcinoma presented with gait dyscoordination and arm pain/weakness. Magnetic resonance imaging showed a C7/T1 mass causing severe compression of the C7/T1 roots and spinal cord. After embolization and tumor resection/fusion, lethargy prompted imaging showing multiple posterior circulation infarcts believed to be secondary to reflux of embolic particles. A 75-year-old man with renal cell carcinoma presented with L1 level metastasis causing conus compression and experienced paraplegia after superselective particle embolization presumed to be secondary to flow disruption of the artery of Adamkiewicz. Analysis of the literature yielded 6 articles reporting instances of cranial infarction/ischemia occurring in 10 patients, 12 articles reporting spinal cord ischemia/infarction occurring in 17 patients, and 5 articles reporting symptomatic postembolization tumoral swelling in 5 patients.

CONCLUSIONS

Neurologic injury is a risk of preoperative embolization of spinal metastasis from either compromise of spinal cord vascular supply or cranial stroke from reflux of embolic particles. Postprocedural tumor swelling rarely leads to clinical deficit. Awareness of these complications and the presumed mechanisms of injury may aid clinicians in implementing interventions and in counseling patients before treatment.

What's new in vertebral cementoplasty?

Vertebral cementoplasty is a well-known mini-invasive treatment to obtain pain relief in patients affected by vertebral porotic fractures, primary or secondary spine lesions and spine trauma through intrametameric cement injection. Two major categories of treatment are included within the term vertebral cementoplasty: the first is vertebroplasty in which a simple cement injection in the vertebral body is performed; the second is assisted technique in which a device is positioned inside the metamer before the cement injection to restore vertebral height and allow a better cement distribution, reducing the kyphotic deformity of the spine, trying to obtain an almost normal spine biomechanics. We will describe the most advanced techniques and indications of vertebral cementoplasty, having recently expanded the field of applications to not only patients with porotic fractures but also spine tumours and trauma.

Surgery in extensive vertebral hemangioma: case report, literature review and a new algorithm proposal

Hemangiomas are benign dysplasias or vascular tumors consisting of vascular spaces lined with endothelium. Nowadays, radiotherapy for vertebral hemangiomas (VHs) is widely accepted as primary treatment for painful lesions. Nevertheless, the role of surgery is still unclear. The purpose of this study is to propose a novel algorithm of treatment about VHs. This is a case report of an extensive VH and a review of the literature. A case of vertebral fracture during radiotherapy at a total dose of 30 Gy given in 10 fractions (treatment time 2 weeks) using a linear accelerator at 15 MV high-energy photons for extensive VH is reported. Using PubMed database, a review of the literature is done. The authors have no study funding sources. The authors have no conflicting financial interests. In the literature, good results in terms of pain and neurological deficits are reported. No cases of vertebral fractures are described. However, there is no consensus regarding the treatment for VHs. Radiotherapy is widely utilized in VHs determining pain. Surgery for VHs determining neurological deficit is also widely accepted. Perhaps, regarding the width of the lesion, no indications are given. We consider it important to make an evaluation before initiating the treatment for the risk of pathologic vertebral fracture, since in radiotherapy, there is no convention regarding structural changes determined in VHs. We propose a new algorithm of treatment. We recommend radiotherapy only for small lesions in which vertebral stability is not concerned. Kyphoplasty can be proposed for asymptomatic patients in which VHs are small and in patients affected by VHs determining pain without spinal canal invasion in which the VH is small. In patients affected by pain without spinal canal invasion but in which the VH is wide or presented with spinal canal invasion and in patients affected by neurological deficits, we propose surgery.