The evolution of pre-operative spine tumour embolization

Preoperative tumor embolization via pedicle artery sacrifice for symptomatic spinal aneurysmal bone cysts: illustrative cases

BACKGROUND

Spinal aneurysmal bone cysts (ABCs) are challenging to manage due to high vascularity and proximity to critical structures. Two patients with large, symptomatic thoracic ABCs are presented.

OBSERVATIONS

Preoperative tumor embolization via pedicle artery sacrifice was performed prior to planned resection to reduce intraoperative blood loss and the risk of postoperative neurological deficits. Less intraoperative blood loss contributes to better surgical visualization and patient stability, thereby promoting maximal safe tumor resection with reduced neurological morbidity. Coil embolization was selected in both cases due to lower risks of nontarget embolization given local feeders to the anterior spinal artery. Provocative methohexital and lidocaine testing was performed with intraoperative monitoring to minimize risk prior to embolizing each vessel.

LESSONS

The indications for preoperative embolization for spinal ABCs remain controversial. The risks associated with this embolization strategy, including those inherent to spinal angiography and embolization as well as increased costs, are potentially outweighed by the benefits of decreased intraoperative blood loss to maximize surgical safety and risks in select patients. In both cases, complete tumor resection was achieved, with the patients experiencing no adverse effects due to embolization, lower-than-expected intraoperative blood loss, and near-complete return of neurological function. https://thejns.org/doi/10.3171/CASE24580.

Pre-operative spine tumour embolization: Clinical outcomes and effect of embolization completeness

INTRODUCTION

To assess the association between the impact of the completeness of pre-operative spine tumour embolisation and clinical outcomes, including estimated blood loss (EBL), neurological status and complications.

METHODS

Retrospective chart review of all preoperative spine tumour embolisation procedures performed over 11 years by a single operator (2007-2018) at Vancouver General Hospital on 44 consecutive patients (mean age 57; 77% males) with 46 embolisation procedures, of which surgery was done en bloc in 26 cases and intralesional in the remaining 20. A multivariable negative binomial regression model was fit to examine the association between EBL and surgery type, tumour characteristics, embolisation completeness and operative duration.

RESULTS

Among intralesional surgeries, complete versus incomplete embolisation was associated with reduced blood loss (772 vs 1428 mL, P < 0.01). There was no statistically significant difference in neurological outcomes or complications between groups. Highly vascular tumours correlated with greater blood loss than their less vascular counterparts, but tumour location did not have a statistically significant effect.

CONCLUSION

This study provides evidence in support of our hypothesis that complete as opposed to incomplete tumour embolisation correlates with reduced blood loss in intralesional surgeries. Randomised control trials with larger samples are necessary to confirm this benefit and to ascertain other potential clinical benefits.

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.

Preoperative embolization of hypervascular spinal tumors: Two case reports

The performance of preoperative embolization on a spinal tumor can be a useful adjunctive procedure that minimizes blood loss and complications, particularly for both metastatic and non-metastatic hypervascular tumors. We discuss two cases of hypervascular spinal tumors that were successfully treated with preoperative embolization and surgery. The first patient was an 18-year-old man who presented with cervical and shoulder pain for two months without paralysis or weakness. Magnetic resonance imaging revealed a tumor located in the D2 posterior vertebral arch that extended into the spinal canal and compressed the spinal cord. The second patient was a 68-year-old man with back pain that radiated to the legs for ten days. Magnetic resonance imaging revealed a mass in the L4 vertebral body. Both patients received tumor embolization and surgery. After surgery, neither patient experienced any major complications. Histological examination revealed osteoblastoma in the first patient and plasmacytoma in the second patient.

Expanding the role of interventional oncology for advancing precision immunotherapy of solid tumors

Adoptive cell therapy with chimeric antigen receptors (CAR) T cells has proven effective for hematologic malignancies, but success in solid tumors has been impeded by poor intratumoral infiltration, exhaustion of effector cells from antigen burden, and an immunosuppressive tumor microenvironment. Results from recent clinical trials and preclinical studies lend promising evidence of locoregional approaches for CAR T cell delivery, priming the tumor microenvironment, and performing adjuvant therapies that sustain T cell activity. Interventional oncology is a subspeciality of interventional radiology where imaging guidance is used to perform percutaneous and catheter-directed procedures for localized, non-surgical therapy or interrogation of solid tumors. Interventional oncology provides unique synergies with immunotherapy, which has been well-studied to improve treatment efficacy while reducing toxicities associated with systemic treatment. Besides aiding in CAR T cell delivery, priming, or the stimulation of the tumor microenvironment to promote effector survival and function, interventional oncology can also aid in the monitoring of treatment response through selective, multiplex tumor sampling and catheter-based venous sampling. This review presents an overview of interventional oncology, its various procedures, and its potential for advancing CAR T cell immunotherapy of solid tumors.

The role of percutaneous transarterial embolization in the management of spinal bone tumors: a literature review

PURPOSE

Spinal bone tumors include a heterogeneous broad of primary or metastatic lesions that may present as incidental findings or manifest with painful symptoms and pathological fractures. Optimal management of spine bone lesions is often difficult and treatment algorithms are usually solidly based on surgery. We aimed to evaluate the contribution of trans-arterial embolization in this field, with particular attention to the procedure efficacy, technical difficulties and complications.

METHODS

We present a literature review on the role of trans-arterial embolization in the management of spinal bone tumors, both primary and metastatic, evaluating its contribution as preoperative treatment, palliative procedure and standalone curative strategy.

RESULTS

Trans-arterial embolization provides an important contribution to reducing surgery hemorrhagic risks, offering a better visualization of the operating field, and possibly increasing tumor susceptibility to chemotherapy or radiation therapy. Nonetheless, it plays an important part in pain palliation, with the unquestionable advantage of being easily repeatable in case of necessity. Its curative role as a standalone therapy is still subject of debate, and at the present time, satisfactory results have been recorded only in the treatment of aneurysmal bone cysts.

CONCLUSION

Percutaneous trans-arterial embolization has established as a highly useful minimally invasive procedure in the management of spinal bone lesions, particularly as adjuvant preoperative therapy and palliative treatment.