Sodium fluorescein in skull base meningiomas: A technical note

Comparison of intraoperative sodium fluorescein and indocyanine green videoangiography during intracranial aneurysm and arteriovenous malformation surgery

OBJECTIVE

Indocyanine green (ICG) and sodium fluorescein (Na-Fl) are two fluorophores, which are used for videoangiography purposes. This prospective study reports our experience by using surgical microscopes equipped with two special filters. We compared the imaging efficacy of Na-FL and ICG videoangiography techniques during aneurysm and arteriovenous malformations (AVM) surgeries.

PATIENT AND METHODS

Fourtynine consecutive patients were operated between September 2015 and December 2022. Patients with ruptured/unruptured aneurysms or with AVMs presented with/without hemorrhage were included to the current study.

RESULTS

There were a total of 48 aneurysms and 11 AVMs in 49 patients in the current study. Na-Fl enables the surgeon to manipulate vessels and aneurysms real-time. ICG provides the ability to watch the videoangiography repeatedly and understand the angioarchitecture. The use of FLOW-800 module allows the surgeon to make concrete judgements about the flow dynamics of AVMs and therefore ICG videoangiography found useful in AVM surgery. Na-Fl has been found more useful for the evalution of the low caliber perforating arteries and anatomical features of the aneursym dome in aneurysm surgery.

CONCLUSION

The results of our series demonstrated the safety and efficacy of Na-Fl use in the surgery of aneurysms and AVMs. Both the ICG and Na-Fl videoangiographies are easy to perform and complimentary to each other. Combined use of these two mediums may provide better surgical results, considering the separate advantages and disadvantages of these both techniques.

Intraoperative Real-Time Near-Infrared Image-Guided Surgery to Identify Intracranial Meningiomas via Microscope

Meningiomas are a common pathology in the central nervous system requiring complete surgical resection. However, in cases of recurrence and post-irradiation, accurate identification of tumor remnants and a dural tail under bright light remains challenging. We aimed to perform real-time intraoperative visualization of the meningioma and dural tail using a delayed-window indocyanine green (ICG) technique with microscopy. Fifteen patients with intracranial meningioma received 0.5 mg/kg ICG a few hours before observation during the surgery. We used near-infrared (NIR) fluorescence to identify the tumor location. NIR fluorescence could visualize meningiomas in 12 out of 15 cases. Near-infrared visualization during the surgery ranged from 1 to 4 h after the administration of ICG. The mean signal-to-background ratio (SBR) of the intracranial meningioma in delayed-window ICG (DWIG) was 3.3 ± 2.6. The ratio of gadolinium-enhanced T1 tumor signal to the brain (T1BR) (2.5 ± 0.9) was significantly correlated with the tumor SBR (p = 0.016). K^trans, indicating blood–brain barrier permeability, was significantly correlated with tumor SBR (p < 0.0001) and T1BR (p = 0.013) on dynamic contrast-enhanced magnetic resonance imaging (MRI). DWIG demonstrated a sensitivity of 94%, specificity of 38%, positive predictive value (PPV) of 76%, and negative predictive value (NPV) of 75% for meningiomas. This is the first pilot study in which DWIG fluorescence-guided surgery was used to visualize meningioma and dural tail intraoperatively with microscopy. DWIG is comparable with second-window ICG in terms of mean SBR. Gadolinium-enhanced T1 tumor signal may predict NIR fluorescence of the intracranial meningioma. Blood–brain barrier permeability as shown by K^trans on dynamic contrast-enhanced MRI can contribute to gadolinium enhancement on MRI and to ICG retention and tumor fluorescence by NIR.

Application of sodium fluorescein for spinal cord lesions: intraoperative localization for tissue biopsy and surgical resection

Sodium fluorescein (NaFL) has been used to aid in the resection of primary and secondary lesions within the brain. Comparatively, there is limited research on clinical applications for lesions within the spinal cord. Fluorescein-guided microsurgery may increase the ability to localize and safely surgically treat spinal lesions. Twelve patients with spinal cord lesions received fluorescein sodium 10% (Alcon Laboratories INC, Fort Worth, TX, USA) at 3 mg/kg prior to surgical resection. Intraoperative visualization of fluorescence was performed using a Zeiss Pentero (Carl Zeiss AG, Oberkochen, Germany) microscope equipped with a Yellow560 filter or a Leica OH6 (Leica Microsystems, Wetzlar, Germany) equipped with a FL560 filter. Administration of NaFL resulted in lesional fluorescent contrast extravasation and facilitated surgical resection and localization in all twelve patients. In patients with a goal of complete resection, NaFL aided in complete resection of the spinal lesions in seven patients. In surgical resection patients, pathology was consistent with WHO grade I myxopapillary ependymoma in one patient, WHO grade II ependymoma in five patients, and nerve sheath tumor in one patient. In the other five patients, NaFL allowed for intraoperative tissue identification and successful tissue biopsy. In patients undergoing biopsy, tissue samples were positive for an intramedullary abscess, EBV-driven lymphoproliferative disease, and primary glial neoplasms. Fluorescein is a helpful microsurgical tool in guiding surgical resection and in the localization of intramedullary spinal lesions. Further research is necessary to explore fluorescein sodium applications in the resection of spinal cord lesions.

Following the light in glioma surgery: a comparison of sodium fluorescein and 5-aminolevulinic acid as surgical adjuncts in glioma resection

Gliomas are molecularly complex neoplasms and require a multidisciplinary approach to treatment. Maximal safe resection is often the initial goal of treatment and extent of resection (EOR) is an important prognostic factor correlating with both progression-free-survival (PFS) and overall survival (OS). Postoperative patient outcome is also a critical and independent prognosticator and high EOR must not be achieved at the expense of good functional outcome. Several intraoperative adjuvant techniques have been developed to help the surgeon push the boundaries of EOR while maintaining safety. Fluorescence-guided surgery for brain tumors is a contemporary adjuvant technique that allows for intraoperative delineation of diseased and normal brain thus improving maximal safe resection. The most extensively used fluorophores are 5-aminolevulinic acid (5-ALA) and sodium fluorescein (SFL). These fluorophores have different spectrophotometric properties, mechanisms of action and considerations for use. Both have demonstrated utility in neurosurgical oncology. They are safe and both are FDA approved for use as surgical adjuncts during resection of primary CNS neoplasms although they have been used with varying success for other tumor types. When combined with other surgical adjuvant strategies such as neuronavigation, intraoperative ultrasound, intraoperative MRI, awake resection and/or electrophysiological mapping/monitoring, fluorescence-guided resection appears to further improve resection quality in regard to EOR and safety. In this article, we review the current knowledge related to both fluorophores for brain tumor resection, their benefits, and pitfalls, as well as the major advantages associated with their use. We also briefly review additional fluorophores in early clinical development. Fluorescence-guided surgery is a novel surgical adjuvant which allows for real-time delineation of neoplastic tissues. The most widely used fluorophores are 5-ALA and SFL. They are safe compounds and there is a large body of evidence suggesting improvement in EOR when these are employed. There are nuances to the use of each; the fluorescence intensity is dose-dependent in either case and the sensitivity and specificity for various tumors vary widely. Additional prospective studies will be necessary to parse the impact of this technique and these fluorophores on survival metrics.

The application of fluorescence techniques in meningioma surgery-a review

Surgical resections of meningiomas, the most common intracranial tumor in adults, can only be curative if radical resection is achieved. Potentially, the extent of resection could be improved, especially in complex and/or high-grade meningiomas by fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA), indocyanine green (ICG), or fluorescein. This review aims to summarize and evaluate these fluorescence-guided meningioma surgery techniques. PubMed and Embase were searched for relevant articles. Additionally, we checked reference lists for further studies. Forty-eight articles were included in the final analysis. 5-ALA fluoresced with varying sensitivity and selectivity in meningiomas and in invaded bone and dura mater. Although ICG was mainly applied for video angiography, one report shows tumor fluorescence 18-28 h post-ICG injection. Lastly, the use of fluorescein could aid in the identification of tumor remnants; however, detection of dural tail is highly questionable. Fluorescence-guided meningioma surgery should be a reliable, highly specific, and sensitive technique. Despite numerous studies reporting the use of fluorescent dyes, currently, there is no evidence that these tools improve the radical resection rate and long-term recurrence-free outcome in meningioma surgery without neurological deficits. Evidence regarding the effectiveness and increased safety of resection after the application of these fluorophores is currently lacking. Future research should focus on the development of a meningioma-targeted, highly sensitive, and specific fluorophore.

Intracranial cystic meningiomas: A series of six patients

OBJECTIVE

Although meningiomas are the most common primary non-glial intracranial tumors, cystic meningiomas are quite rare. This study presents six cases in order to discuss the radiological and pathological features of cystic meningiomas.

PATIENTS AND METHODS

Six patients with cystic meningiomas were included in the study. All patients underwent a cranial computed tomography scan and magnetic resonance imaging (MRI) evaluation, pre- and postoperatively.

RESULTS

All patients presented with long standing headache dating back at least two years. There was no gender predominance in our series. Radiological evaluation revealed two parasagittal and two convexity meningiomas located at the frontal region. Two lesions were located at the tuberculum sellae and the foramen magnum. All of the tumors were totally excised (Simpson Grade I or II). Pathology results included meningothelial meningioma in three patients, angiomatous meningioma in two patients, and metaplastic meningioma in one patient. In two patients, the cystic meningiomas were resected with the use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter. Na-Fl was found to be very useful in demonstrating the brain-tumor interface, and it was especially effective in resecting the cyst wall of the peritumoural cystic meningiomas. None of the patients had any complications, and no recurrences were noted in any of the patients within the mean follow-up period of 51 months (range: 16-102 months).

CONCLUSION

It is important to note MRI changes specific to cystic meningioma and include meningiomas in the differential diagnosis of intracranial cystic lesions. The use of sodium fluorescein (Na-Fl) under a YELLOW 560nm microscope filter is a useful tool to differentiate the brain-tumor interface, as well as to identify the cyst wall in order to fully resect the tumor with the cystic component to avoid recurrence and achieve better clinical results.

Fluorescein-Guided Surgery for Pediatric Brainstem Gliomas: Preliminary Study and Technical Notes

Introduction  Brainstem gliomas (BsG) account for 10 to 15% of pediatric brain tumors. Surgery is the preferred treatment for focal and exophytic lesions. Sodium fluorescein has been proven safe and effective in resection of malignant brain tumors. Objective  The objective was to o analyze the safety and effectiveness of this approach, to evaluate intraoperative fluorescein imaging, and to measure the safety of chosen dose for pediatric patients. Methods  Twelve cases were enrolled between March 2014 and September 2016 in Beijing Tiantan Hospital. All of the patients received 2.5 mg/kg of sodium fluorescein before opening the dura; the intraoperative fluorescence enhancement was observed, and the degree of satisfaction and consistency with the neuronavigation were evaluated. Results  With a mean age of 7.5 years, there were eight cases located within the pontine, three in the medullary oblongata, and one in the tectal plate. Histological results were astrocytoma, glioblastoma, oligodendroglioma, and pilocytic astrocytoma. Under the fluorescein module of the microscope, the tumors were recognizable enough to help surgeons to discriminate the lesion from non-fluorescent tissue, with a consistency of 83% with the neuronavigation. Total removal was accomplished in nine cases, while the mean percentage of resection of the other cases was 93.7%. The Karnofsky performance score (KPS) showed no significant differences between pre-operation and discharge, but there was a difference between pre-operation and 6-month follow-up. Conclusion  The fluorescein-guided surgery is useful for demarcating the tumor margin and works well with other navigation and monitoring devices. A safe dose of sodium fluorescein (2.5 mg/kg) was proven effective for children.

The utilization of fluorescein in brain tumor surgery: a systematic review

INTRODUCTION

Sodium fluorescein (SF) is a green, water-soluble dye with the capacity to accumulate in cerebral areas as a result of damaged blood-brain barrier (BBB); this property allows SF to concentrate specifically at the tumor site of various types of brain neoplasms, making the tumor tissue more clearly visible.

EVIDENCE ACQUISITION

A literature search (1947-2018) was conducted with the keywords "fluorescein neurosurgery," "YELLOW neurosurgery," "fluorescein brain tumor," "YELLOW brain tumor." We included clinical studies, clinical trials, observational studies, only conducted on humans and concerning surgery; in addition, we have included 3 articles derived from the analysis of the references of other papers. Ultimately, 57 articles were included for further analysis.

EVIDENCE SYNTHESIS

Fluorescein as a fluorescent tracer in neuro-oncology is gaining a wider acceptance in the neurosurgical literature: until February 1st, 2018, at least 1099 neuro-oncological patients have been operated through fluorescein-assistance, mostly only after 2012. The most important application remains the aim to improve tumor visualization and extent of resection for high-grade gliomas (HGG), but the nonspecific mechanism of action is the theoretical base for its use also for tumors different from HGG. Nevertheless, no homogenous protocol of fluorescein utilization in neurosurgical oncology can be found in literature.

CONCLUSIONS

Fluorescein-guided surgery is a safe and effective technique to improve visualization and resection of different CNS tumors and conditions, based on BBB alteration, with a growing evidence-based background.

Current thinking about the management of recurrent pleomorphic adenoma of the parotid: a structured review

Pleomorphic adenoma is the most common tumour of the parotid gland, and can recur after excision. Recurrent pleomorphic adenoma can be a challenge to treat, and has variable outcomes. The aim of this review was to summarise current thinking in its management, which may be helpful to clinical teams and could improve patients' health-related quality of life. We searched several online databases using the key terms pleomorphic adenoma, recurrent pleomorphic adenoma, parotid gland tumours, parotid surgery, radiotherapy and parotid pleomorphic adenoma, and parotid surgery outcomes. Information collected included sample size, recurrence rate, condition of the facial nerve, type of operation, adjuvant treatments associated with recurrence, and clinical outcome. We screened 2301 papers, of which 49 were eligible. There was no consensus among authors about management. There are few if any randomised studies, and so conclusions in most papers were based on coherent arguments. Pleomorphic adenomas of the parotid tend to recur after long intervals, with a propensity towards multifocal disease, and the risk of recurrence (which depends on the initial surgical technique) is higher when the initial operation was done at a young age, after enucleation, and if the initial margins were invaded. Published conclusions suggest that the accepted management varies from observation in selected cases to total parotidectomy with or without postoperative radiotherapy.

Fluorescein sodium-guided resection of intracranial lesions in 22 dogs

OBJECTIVE

To evaluate the safety of an intraoperative fluorescein sodium (FS) injection and elucidate the relationships between the MRI findings, pathological diagnoses, and intraoperative staining characteristics of intracranial lesions in 22 dogs.

STUDY DESIGN

Prospective case series.

ANIMALS

Twenty-two dogs with intracranial lesions.

METHODS

FS was intravenously administered to 22 dogs undergoing craniotomy for suspected intracranial tumors to evaluate perioperative and postoperative adverse effects. The intensities and patterns of gadolinium (Gd) enhancement on preoperative magnetic resonance imaging and intraoperative FS staining were graded, and their relationship was evaluated. Intraoperative FS staining characteristics and pathological diagnoses were compared.

RESULTS

The only adverse effect noted was repetitive vomiting in 2 dogs. The intensities and patterns between preoperative Gd enhancement and intraoperative FS staining appeared to agree. High-grade glioma and histiocytic sarcoma had more intense FS staining. Lesions with strong Gd enhancement, including meningiomas and choroid plexus tumors, also had intense FS staining.

CONCLUSION

The intraoperative use of FS is a simple and safe technique to guide the resection of intracranial lesions in dogs. The findings on Gd enhancement, FS staining, and histopathology appeared to agree but require validation in a larger set of cases.

CLINICAL SIGNIFICANCE

The intraoperative use of FS may improve the prognosis of dogs with brain tumors by guiding the resection of lesions.

Sodium Fluorescein Facilitates Guided Sampling of Diagnostic Tumor Tissue in Nonenhancing Gliomas

BACKGROUND

Accurate tissue sampling in nonenhancing (NE) gliomas is a unique surgical challenge due to their intratumoral histological heterogeneity and absence of contrast enhancement as a guide for intraoperative stereotactic guidance. Instead, T2/fluid-attenuated inversion-recovery (FLAIR) hyperintensity on MRI is commonly used as an imaging surrogate for pathological tissue, but sampling from this region can yield nondiagnostic or underdiagnostic brain tissue. Sodium fluorescein is an intraoperative fluorescent dye that has a high predictive value for tumor identification in areas of contrast enhancement and NE in glioblastomas. However, the underlying histopathological alterations in fluorescent regions of NE gliomas remain undefined.

OBJECTIVE

To evaluate whether fluorescein can identify diagnostic tissue and differentiate regions with higher malignant potential during surgery for NE gliomas, thus improving sampling accuracy.

METHODS

Thirteen patients who presented with NE, T2/FLAIR hyperintense lesions suspicious for glioma received fluorescein (10%, 3 mg/kg intravenously) during surgical resection.

RESULTS

Patchy fluorescence was identified within the T2/FLAIR hyperintense area in 10 of 13 (77%) patients. Samples taken from fluorescent regions were more likely to demonstrate diagnostic glioma tissue and cytologic atypia (P &lt; .05). Fluorescein demonstrated a 95% positive predictive value for the presence of diagnostic tissue. Samples from areas of fluorescence also demonstrated greater total cell density and higher Ki-67 labeling than nonfluorescent biopsies (P &lt; .05).

CONCLUSION

Fluorescence in NE gliomas is highly predictive of diagnostic tumor tissue and regions of higher cell density and proliferative activity.

Fluorescence-guided surgery of brain abscesses

OBJECTIVES

Fluorescein Sodium (FL) enhances areas in the brain with a disrupted blood brain barrier (BBB). Solitary brain abscesses (BA) are characterized by the pathognomonic finding of BBB disruption. Consequently, FL may have the potential to improve the intra-operative visualization of BA. Here, we report a series of patients with BA that where treated surgically after application of FL in combination with a dedicated light filter integrated in the surgical microscope.

METHODS

7 patients (4 female, 3 male; mean age 53.8 years) with BA were included, all of them gave written informed consent. 5mg/kg bodyweight of FL was administered via the central venous line at induction of anesthesia, approximately 30-45min prior to surgery. We screened the surgical reports for any statement concerning the intensity of fluorescent staining.

RESULTS

Fluorescent staining was bright in all patients. Surgical removal of all parts of the BA, aspiration of pus and dissection of the capsule, were performed in the fluorescence-mode under the filtered light. We encountered no adverse events.

CONCLUSION

The accumulation of FL resulted in brilliant visualization of the infected area under the YELLOW 560nm filter. This small clinical study adds to the rapidly emerging clinical experiences of the use of fluorescein in neurosurgery, even for non-neoplastic lesions. However, prospective and randomized clinical trials are still necessary to establish the beneficial use of FL.

Minimally invasive surgery of the anterior skull base: transorbital approaches

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach.

Severe Edema and Venous Congestion Following Sphenoorbital Meningioma Resection in a Meningiomatosis Case: Importance of Predicting Venous Disturbances

To achieve local disease control, radical removal is the best option for sphenoorbital meningiomas. Preservation of the venous system is crucial during the resection of skull base meningiomas. This vascular injury represents a major risk both for life and neurologic function. We present a case of a severe postoperative frontotemporal venous disturbance and cerebral edema following the radical removal of a giant sphenoorbital meningioma in a patient with meningiomatosis and occlusion of the superior sagittal sinus. The anatomical, radiologic, and surgical aspects are reviewed and discussed, with the aim of preventing such a serious complication.

Recurrence of Skull Base Meningiomas: The Role of Aggressive Removal in Surgical Treatment

Objectives The recurrence of meningiomas is a crucial aspect that must be considered during the planning of treatment strategy. The Simpson grade classification is the most relevant surgical aspect to predict the recurrence of meningiomas. We report on a series of patients with recurrent skull base meningiomas who were treated with the goal of radical removal. Design A retrospective study. Setting Hospital Ernesto Dornelles, Porto Alegre, Brazil. Participants Patients with recurrent skull base meningiomas. Main Outcomes Measures The goal of obtaining aggressive resection (i.e., Simpson grades I and II). Results The average age was 54 years, the mean follow-up period was 52.1 months, and Simpson grades I and II were obtained in 82%. The overall mortality was 5.8%. Transient cranial nerve deficits occurred in 11.7%; the definitive morbidity was also 5.8%. A second recurrence occurred in 5.8%. Conclusions Radical removal of recurrent skull base meningiomas is achievable and should be considered an option with a good outcome and an acceptable morbidity. The common surgical finding that was responsible for recurrence in this study was incomplete removal during the first surgery. We recommend extensive dura and bone removal in the surgical treatment of such recurrent lesions.

Large and giant skull base meningiomas: The role of radical surgical removal

Background:

The large and giant skull base meningiomas are challenging lesions, and the involvement of crucial neurovascular structures needs the surgical removal as the primordial treatment. The authors report on a series of patients with large and giant skull base meningiomas who were treated with the goal of radical removal.

Methods:

A retrospective study including 49 patients with large and giant skull base meningiomas was carried out. Tumors presenting 3 cm or larger were included.

Results:

The meningiomas in the sample included the following types: 10 olfactory groove, 8 sphenoorbital, 8 petroclival, 8 tentorial, 4 clinoidal, 4 cavernous sinus, 3 temporal floor, 2 tuberculum sellae and 2 foramen magnum. The average age was 53 years, the mean follow-up period was 52 months, Simpson Grades I and II were obtained in 75.5%. The overall mortality was 5%. Transient cranial nerve deficits occurred in 32% with definite cranial nerve lesion in 18%. Cerebrospinal fluid leak occurred in 14%.

Conclusions:

The surgical treatment is a mandatory option for large and giant skull base meningiomas. The radical removal is achievable and should be considered an alternative with a good outcome and an acceptable morbidity for such challenge lesions.