Fluorescein-guided surgery for intradural spinal tumors: A single-center experience

Spinal Intramedullary Meningiomas: A Systematic Review with a Case Illustration

BACKGROUND

Intramedullary meningiomas are an exceptionally rare subtype of spinal tumors, accounting for only 5% of primary spinal neoplasms. Given their scarcity and unique characteristics, understanding optimal management approaches is crucial for improved clinical decision-making. This systematic review aims to consolidate existing literature and present a detailed case illustration to enhance understanding of this uncommon spinal tumor entity.

METHODS

A systematic search adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. Eligible studies included case reports, case series, cohort studies, reviews, and meta-analyses. Data extraction and synthesis focused on demographic characteristics, tumor location, clinical presentation, imaging findings, surgical interventions, histopathological features, and outcomes.

RESULTS

A total of 15 high-quality scientific articles were included in the systematic review, providing insights into various aspects of intramedullary meningiomas. Demographic analysis revealed a broad age distribution with an equal gender distribution among affected patients. Common clinical presentations included difficulty walking, sensory disturbances, spastic paraparesis, and urinary incontinence. Neuroimaging findings demonstrated heterogeneous signal intensity variations on T1- and T2-weighted images, with variable enhancement patterns on gadolinium-enhanced images. Surgical interventions, predominantly total resection, resulted in favorable postoperative outcomes in most cases.

CONCLUSIONS

Intramedullary meningiomas pose diagnostic and therapeutic challenges due to their rarity and unique characteristics. Tailored surgical approaches, incorporating techniques such as intraoperative neurophysiological monitoring and fluorescence-aided resection, are crucial for minimizing neurological deficits and optimizing patient outcomes. Despite their infrequency, recognizing intramedullary meningiomas in the differential diagnosis of spinal tumors is essential for prompt diagnosis and timely intervention, ultimately improving patient prognosis.

Fluorescence-guided resection of intradural spinal tumors: a systematic review and meta-analysis

Intradural spinal tumors present significant challenges due to involvement of critical motor and sensory tracts. Achieving maximal resection while preserving functional tissue is therefore crucial. Fluorescence-guided surgery aims to improve resection accuracy and is well studied for brain tumors, but its efficacy has not been fully assessed for spinal tumors. This meta-analysis aims to delineate the efficacy of fluorescence guidance in intradural spinal tumor resection. The authors performed a systematic review in four databases. We included studies that have utilized fluorescence agents, 5-aminolevulinic acid (5-ALA) or sodium fluorescein, for the resection of intradural spinal tumors. A meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 12 studies involving 552 patients undergoing fluorescence-guided intradural spinal tumor resection were included. Meningiomas demonstrated a 98% fluorescence rate and were associated with a homogenous florescence pattern; however, astrocytomas had variable fluorescence rate with pooled proportion of 70%. There was no significant difference in gross total resection (GTR) rates between fluorescein and 5-ALA (94% vs 84%, p = .22). Pre-operative contrast enhancement was significantly associated with intraoperative fluorescence with fluorescein. Intramedullary tumors with positive intraoperative fluorescence were significantly associated with higher GTR rates (96% vs 73%, p = .03). Utilizing fluorescence guidance during intradural spinal tumor resection holds promise of improving intraoperative visualization for specific intradural spinal tumors. Meningiomas and ependymomas have the highest fluorescence rates especially with sodium fluorescein; on the other hand, astrocytomas have variable fluorescence rates with no superiority of either agent. Positive fluorescence of intramedullary tumors is associated with a higher degree of resection.

Intraoperative Fluorophores: An Update on 5-Aminolevulinic Acid and Sodium Fluorescein in Resection of Tumors of the Central Nervous System and Metastatic Lesions-A Systematic Review and Meta-Analysis

INTRODUCTION

Recent advances in tumor visualization have improved the extent of resection (EOR) of primary and secondary tumors of the central nervous system, while limiting the morbidity and mortality of the surgery. One area of recent interest has been the use of intraoperative fluorophores for tumor visualization such as 5-aminolevulinic acid (5-ala) and sodium fluorescein. We performed a systematic review and meta-analysis on the utility of fluorophore administration and EOR with each fluorophore to update the current literature.

METHODS

We conducted a systematic review and meta-analysis on the use of intraoperative 5-ala or fluorescein between 2021 and 2023 using the PubMed, SCOPUS, and WOS databases. The initial search yielded 8688 results. After inclusion and exclusion criteria were met, 44 studies remained for review. A meta-analysis was performed to compare the EOR between studies for each fluorophore and to compare the presence of intraoperative fluorescence by tumor type. Odds ratios (OR) were calculated for gross total resection (GTR), and two-way ANOVA tests were performed to compare rates of intraoperative fluorescence by fluorophore and tumor type.

RESULTS

In all groups except low-grade glioma, fluorescence was present after 5-ala administration; fluorescence was present for all groups after fluorescein administration. Two-way ANOVA analysis for both fluorophores demonstrated no statistically significant difference in presence of fluorescence between type of tumor resected. Meta-analysis of EOR did show a higher, but not significant, rate of GTR in the 5-ala group compared to controls (OR = 1.29, 95% CI = 0.49; 3.37). In the fluorescein group, there were statistically significant higher odds of GTR compared to the control group (OR = 2.10, 95% CI = 1.43; 3.10, I2 = 0%).

CONCLUSIONS

Both 5-ala and sodium fluorescein demonstrated intraoperative fluorescence among various tumor types in both cranial and spinal tumors, as well as efficacy in improving EOR. Both fluorophores merit further investigation for use in surgery of CNS tumors.