Efficacy of radiotherapy and stereotactic radiosurgery as adjuvant or salvage treatment in atypical and anaplastic (WHO grade II and III) meningiomas: a systematic review and meta-analysis.

The role of radiotherapy (RT) and stereotactic radiosurgery (SRS) as adjuvant or salvage treatment in high-grade meningiomas (HGM) is still debated. Despite advances in modern neuro-oncology, HGM (WHO grade II and III) remains refractory to multimodal therapies. Published reports present aggregated data and are extremely varied in population size, exclusion criteria, selection bias, and inclusion of mixed histologic grades, making it extremely difficult to draw conclusions when taken individually. This current work aims to gather the existing evidence on RT and SRS as adjuvants following surgery or salvage treatment at recurrence after multimodality therapy failure and to conduct a systematic comparison between these two modalities. An extensive systematic literature review and meta-analysis were performed. A total of 42 papers were eligible for final analysis (RT n = 27; SRS n = 15) after searching MEDLINE via PubMed, Web-of-science, Cochrane Wiley, and Embase databases. Adjuvant regimens were addressed in 37 papers (RT n = 26; SRS n = 11); salvage regimens were described in 5 articles (RT n = 1; SRS n = 4). The primary outcomes of the study were the overall recurrence rate and mortality. Other actuarial rates (local and distant control, OS, PFS, and complications) were retrieved and analyzed as secondary outcomes. A total of 2853 patients harboring 3077 HGM were included. The majority were grade II (87%) with a mean pre-radiation volume of 8.7 cc. Adjuvant regimen: 2742 patients (76.4% RT; 23.6% SRS) with an overall grade II/III rate of 6.6/1. Lesions treated adjSRS were more frequently grade III (17 vs 12%, p < 0.001), and received subtotal resection (57 vs 27%, p = 0.001) compared to the RT cohort. AdjSRS cohort had a significantly shorter mean follow-up than adjRT (36.7 vs 50.3 months, p = 0.01). The overall recurrence rate was 38% in adjRT vs 25% in adjSRS (p = 0.01), while mortality did not differ between the groups (20% vs 23%, respectively; p = 0.80). The median time to recurrence was 1.5 times longer in the RT group (p = 0.30). Five-year local control was 55% in adjRT and 26% in adjSRS (p = 0.01), while 5-year OS was 73% and 78% (p = 0.62), and 5-year PFS was 62% and 40% in adjRT and adjSRS (p = 0.008). No difference in the incidence of complications (24% vs 14%, p = 0.53). Salvage regimen: 110 patients (37.3% RT; 62.7% SRS) with a grade II/III rate of 8.6/1. The recurrence rate was 46% in salRT vs 24% in salSRS (p = 0.39), time to recurrence was 1.8 times longer in the salRT group (35 vs 18.5 months, p = 0.74). Mortality was slightly yet not significantly higher in salRT (34% vs 12%, p = 0.54). Data on local and distant control were only available for salSRS. The 5-year OS was 49% and 83% (p = 0.90), and the 5-year PFS was 39% and 50% in salRT and salSRS (p = 0.66), respectively. High-grade meningiomas (WHO grade II and III) receiving adjuvant RT showed a higher overall recurrence rate than meningiomas receiving adjuvant SRS. The adjRT cohort, however, achieved higher 5-year LC and PFS rates, thus suggesting a potentially longer time to recurrence compared to adjSRS patients, who, meanwhile, experienced a significantly shorter follow-up. This result must also consider the higher number of grade III lesions and the smaller extent of resection achieved in the adjSRS group. Overall mortality did not differ between the two groups. No differences in outcome measures were observed in salvage regimens.

Evaluating risk of recurrence in patients with meningioma.

OBJECTIVE: Meningioma prognostication and treatment continues to evolve with an increasing understanding of tumor biology. In this study, the authors aimed to test conventional predictors of meningioma recurrence, histopathology variables for which there exists some controversy (brain invasion), as well as a novel molecular-based location paradigm. METHODS: This is a retrospective study of a consecutive series of patients with WHO grade I-III meningioma resected at The University of Texas Southwestern Medical Center between 1994 and 2015. Time to meningioma recurrence (i.e., recurrence-free survival [RFS]) was the primary endpoint measured. Kaplan-Meier curves were constructed and compared using log-rank tests. Cox univariate and multivariate analyses were performed to identify predictors of RFS. RESULTS: A total of 703 consecutive patients with meningioma underwent resection at The University of Texas Southwestern Medical Center between the years 1994 and 2015. A total of 158 patients were excluded for insufficient follow-up (< 3 months). The median age of the cohort was 55 years (range 16-88 years) and 69.5% (n = 379) were female. The median follow-up was 48 months (range 3-289 months). There was not a significantly increased risk of recurrence in patients with evidence of brain invasion, in patients with otherwise WHO grade I meningioma (Cox univariate HR 0.92, 95% CI 0.44-1.91, p = 0.82, power 4.4%). Adjuvant radiosurgery to subtotally resected WHO grade I meningiomas did not prolong the time to recurrence (n = 52, Cox univariate HR 0.21, 95% CI 0.03-1.61, p = 0.13, power 71.6%). Location (midline skull base, lateral skull base, and paravenous) was significantly associated with RFS (p < 0.01, log-rank test). In patients with high-grade meningiomas (WHO grade II or III), location was predictive of RFS (p = 0.03, log-rank test), with paravenous meningiomas exhibiting the highest rates of recurrence. Location was not significant on multivariate analysis. CONCLUSIONS: The data suggest that brain invasion does not increase the risk of recurrence in otherwise WHO grade I meningioma. Adjuvant radiosurgery to subtotally resected WHO grade I meningiomas did not prolong the time to recurrence. Location categorized by distinct molecular signatures did not predict RFS in a multivariate model. Larger studies are needed to confirm these findings.

Combined Anterior (Kawase) and Posterior Petrosectomy (pre-sigmoid/ retro-labyrinthine) for Resection of Post-Radiosurgery Recurrent Cavernous Sinus and Meckel's cave Meningioma; with Simultaneous Microvascular Decompression for Trigeminal Neuralgia: 2 Dimensional Operative video, and Review of Literature.

BACKGROUND: A 70-year male had previous gamma knife (GK) for left cavernous sinus and Meckel's cave meningioma for facial numbness. He presented 11 years later with facial pain (both typical and atypical) and worsening numbness. OBSERVATIONS: MRI showed tumor growth and an infratentorial extension. FIESTA MRI showed left superior cerebellar artery (SCA) contact with the V nerve root entry zone (REZ) accounting for Type 1/ lancinating pain. After discussing available options, he opted for surgery. Lumbar drain, and a middle fossa anterior petrosectomy (Kawase) combined with posterior petrosectomy (retrolabyrinthine) approach was employed to perform tumor debulking along with microvascular decompression (mobilization of SCA). SSEP, BAERS, MEP, V nerve monitoring were performed. Fat graft was used for multilayered closure. He experienced resolution of both type 1 & type 2 facial pain, improvement in sensation in V3. Symptomatic improvement was recorded at 11 months follow up. LESSONS: The combined skull base approach provided visualization of the entire length of V nerve (Cisternal, Meckel's cave, V2 and V3) allowing for decompression at various points to achieve relief of both types of facial pain. The patient provided consent for use of his images and operative video for publication.

Tranexamic acid use in meningioma surgery - A systematic review and meta-analysis.

Tranexamic Acid (TXA) has been used in medical and surgical practice to reduce haemorrhage. The aim of this review was to evaluate the effect of TXA use on intraoperative and postoperative outcomes of meningioma surgery. A systematic review and meta-analysis was conducted in accordance with the PRISMA statement and registered in PROSPERO (CRD42021292157). Six databases were searched up to November 2021 for phase 2-4 control trials or cohort studies, in the English language, examining TXA use during meningioma surgery. Studies ran outside of dedicated neurosurgical departments or centres were excluded. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. Random effects meta-analysis were performed to delineate differences in operative and postoperative outcomes. Four studies (281 patients) were included. TXA use significantly reduced intraoperative blood loss (mean difference 315.7 mls [95% confidence interval [CI] -532.8, -98.5]). Factors not affected by TXA use were transfusion requirement (odds ratio = 0.52; 95% CI 0.27, 0.98), operation time (mean difference = -0.2 h; 95% CI -0.8, 0.4), postoperative seizures (Odds Ratio [OR] = 0.88; 95% CI 0.31, 2.53), hospital stay (mean difference = -1.2; 95% CI -3.4, 0.9) and disability after surgery (OR = 0.50; 95% CI 0.23, 1.06). The key limitations of this review were the small sample size, limited data for secondary outcomes and a lack of standardised method for measuring blood loss. TXA use reduces blood loss in meningioma surgery, but not transfusion requirement or postoperative complications. Larger trials are required to investigate the impact of TXA on patient-reported postoperative outcomes.

High definition 4K-three-dimensional exoscope for removal of a C1-C2 meningioma: Technical case report / Meningioma espinal C1-C2 extirpado con un exoscopio tridimensional y resolución 4K: reporte técnico de caso clínico

In recent years, the exoscope has been proposed as an alternative to the microscope when a magnified view of the surgical field is required in spinal surgery. We present a case of a 52-year-old patient in which a meningioma in the upper cervical spine (C1-C2) was removed using a 4K-three-dimensional (3D) exoscope. The advantages of surgical removal of an intradural spinal tumor using an exoscope are illustrated, focusing mainly on vision quality and ergonomics. In addition, some technical details regarding the operating room setup are provided. Based on this experience, a 4K-3D exoscope can be useful for spinal tumor surgery when high magnification of anatomical details is required, allowing the surgeon to operate in a comfortable position throughout the surgical procedure. (AU)

En los últimos años, el exoscopio se ha propuesto como alternativa al microscopio cuando se requiere una visión ampliada del campo quirúrgico, incluso en la cirugía de la columna vertebral. Presentamos un caso clínico de un paciente de 52 años en el que se extirpó un meningioma en la columna cervical superior (C1-C2) utilizando un exoscopio tridimensional con resolución 4K (4K-3D). Se ilustran las ventajas de la extirpación quirúrgica de un tumor espinal intradural con exoscopio, centrándose principalmente en la calidad de la visión y en la ergonomía. Además, se ofrecen algunos detalles técnicos sobre la configuración del quirófano. Nuestra experiencia sugiere que un exoscopio 4K-3D puede ser muy útil para la cirugía de tumores espinales cuando se requiere una gran ampliación de los detalles anatómicos, permitiendo también al cirujano operar en una posición cómoda durante todo el procedimiento quirúrgico. (AU)

Prognosis and histology of sporadic synchronous and metachronous meningiomas and comparative analyses with singular lesions.

Synchronous or metachronous growth of multiple tumors (≥ 2) is found in up to 20% of meningioma patients. However, biological as well as histological features and prognosis are largely unexplored. Clinical and histological characteristics were retrospectively investigated in 95 patients harboring 226 multiple meningiomas (MMs) and compared with 135 cases of singular meningiomas (SM) using uni- and multivariate analyses. In MM, tumors occurred synchronously and metachronously in 62% and 38%, respectively. WHO grade was intra-individually constant in all but two MMs, and histological subtype varied in 13% of grade 1 tumors. MM occurred more commonly in convexity/parasagittal locations, while SM were more frequent at the skull base (p < .001). In univariate analyses, gross total resection (p = .014) and high-grade histology in MM were associated with a prolonged time to progression (p < .001). Most clinical characteristics and rates of high-grade histology were similar in both groups (p ≥ .05, each). Multivariate analyses showed synchronous/metachronous meningioma growth (HR 4.50, 95% CI 2.26-8.96; p < .001) as an independent predictor for progression. Compared to SM, risk of progression was similar in cases with two (HR 1.56, 95% CI .76-3.19; p = .224), but exponentially raised in patients with 3-4 (HR 3.25, 1.22-1.62; p = .018) and ≥ 5 tumors (HR 13.80, 4.06-46.96; p < .001). Clinical and histological characteristics and risk factors for progression do not relevantly differ between SM and MM. Although largely constant, histology and WHO grade occasionally intra-individually vary in MM. A distinctly higher risk of disease progression in MM as compared to SM might reflect different underlying molecular alterations.

Preoperative meningioma vascularity index is associated with significantly increased intraoperative blood loss and greater risk of subtotal resection.

OBJECTIVE: Surgical recovery of meningiomas relies on a variety of factors, including tumor volume, vascularity, embolization status, and blood loss during excision. Although hypervascular meningiomas can potentially be amendable to embolization, methods for determining optimal vascularity for this procedure are currently lacking. Our group previously established the meningioma vascularity index (MVI) as a marker of tumor vascularity. In this study, we aim to build on our previous work and further examine the relationship between MVI and intraoperative estimated blood loss (EBL). METHODS: A retrospective data extraction was conducted between August 2010 and October 2019 from patients undergoing craniotomy for meningioma. Of the 85 intracranial meningiomas included, 39 were embolized. Demographic data, extent of resection, embolization status, and EBL were among the extracted variables. Flow void volumes were measured on T2-weighted MRI images using a segmentation software with a voxel-based segmentation method. RESULTS: MVI was a predictor of EBL within the entire cohort, when controlling for tumor volume (R2 adjusted = 0.26; P = 0.027). A high MVI (> 2.01 cm3) was associated with higher likelihood of receiving subtotal resection (STR) (OR 4.07, 95% CI 1.17-14.15; P = 0.035). Although the mean MVI and tumor volume were higher in the embolized cohort (P = 0.009 and P = 0.005), there were no significant differences in EBL, or blood transfusion rates regardless of embolization status. CONCLUSIONS: MVI may be used as a non-invasive radiological marker to gauge meningioma vascularity, predict EBL, and guide the decision-making process when it comes to embolization and surgical planning.

Association between preoperative hematologic markers and aggressive behavior in meningiomas.

INTRODUCTION: Meningiomas have varying degrees of aggressive behavior. Some systemic hematologic makers are associated with malignancy, but their value in predicting aggressive meningioma behavior is not fully understood. OBJECTIVE: To evaluate the association between preoperative markers such as neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and prognostic nutritional index (PNI), and diagnostic and prognostic factors including WHO grade, proliferation index, presence of edema on preoperative MRI, and tumor recurrence. METHODS: A retrospective review of patients treated between 2000 and 2019 with a preoperative complete blood count (CBC) differential lab draw before intracranial meningioma resection was conducted. All preoperative steroid dosages were converted to dexamethasone equivalents. Primary outcomes included presence/absence of perilesional edema, WHO grade, Ki-67/MIB-index, and recurrence. Univariate and multivariable regression analyses were conducted. RESULTS: A total of 209 meningioma patients were included. Of these, 143 (68 %) were WHO grade I, 61 (29 %) grade II and 5 (2 %) were grade III. Recurrence was reported in 19 (9.1 %) tumors. No hematologic markers were associated with recurrence. In separate multivariable logistic analyses, no biomarkers were associated with perilesional edema or WHO grade. MLR was associated with higher MIB-index (p = 0.018, OR 6.57, 95 % CI 1.37-30.91). CONCLUSION: Most hematologic markers were not associated with meningioma invasiveness, grade, proliferative index, or aggressiveness. Preoperative MLR was associated with high proliferation index in patients undergoing surgery for intracranial meningioma. Higher MLR could be a surrogate for meningioma proliferation and has potential to be used as an adjunct for risk-stratifying meningiomas.

[Bone defect closure after resection of sphenoorbital meningioma]. / Rekonstruktsiya kostnykh defektov posle udaleniya kranioorbital'nykh meningiom.

Sphenoorbital meningiomas (SOM) are a subgroup of skull base tumors with soft tissue component in the orbit and anterior and/or middle cranial fossa. According to different authors, SOMs account for 2-12% of all intracranial meningiomas. Reconstruction of bone defects after resection of SOM has own nuances. Along with cranial vault repair, patients encounter with cosmetic defects following facial skull lesion, ophthalmic symptoms due to orbital defects, dental and functional problems associated with opening of the mouth in case of damage to maxilla and mandible. Predominant infiltrative growth of tumor and common large bone defects involving various anatomical regions require multiple implants or implants with complex shape. Moreover, contact of implantation area with nasal cavity and paranasal sinuses requires additional impermeability of soft tissue reconstruction and inertness of materials. OBJECTIVE: To summarize available modern data on bone defect closure after resection of SOM. MATERIAL AND METHODS: The authors reviewed available data on bone defect closure after resection of SOM. Effectiveness of modern methods of reconstruction and safety of materials were assessed. RESULTS: We analyzed 96 available references. Technical features of tumor resection, materials used for bone defect closure and modern possibilities of 3D technologies in reconstructive surgery were described. The authors proposed the algorithms for selecting the materials for bone defect closure after resection of SOM. CONCLUSION: Improvement of surgical technique and development of new materials and technologies significantly improve cosmetic and functional results. A large percentage of negative ophthalmologic outcomes and high risk of complications in SOM surgery require further studies and elaboration of modern techniques.

Can Apparent Diffusion Coefficient (ADC) maps replace Diffusion Tensor Imaging (DTI) maps to predict the volumetric response of meningiomas to Gamma Knife Radiosurgery?

PURPOSE: Noninvasive methods are desired to predict the treatment response to Stereotactic Radiosurgery (SRS) to improve individual tumor management. In a previous study, we demonstrated that Diffusion Tensor Imaging (DTI)-derived parameter maps significantly correlate to SRS response. This study aimed to analyze and compare the predictive value of intratumoral ADC and DTI parameters in patients with meningiomas undergoing radiosurgery. METHODS: MR images of 70 patients treated with Gamma Knife SRS for WHO grade I meningiomas were retrospectively reviewed. MR acquisition included pre- and post-treatment DWI and DTI sequences, and subtractions were calculated to assess for radiation-induced changes in the parameter values. RESULTS: After a mean follow-up period (FUP) of 52.7 months, 69 of 70 meningiomas were controlled, with a mean volume reduction of 34.9%. Whereas fractional anisotropy (FA) values of the initial exam showed the highest correlation to tumor volume change at the last FU (CC = - 0.607), followed by the differences between first and second FU values of FA (CC = - 0.404) and the first longitudinal diffusivity (LD) value (CC = - 0.375), the correlation coefficients of all ADC values were comparably low. Nevertheless, all these correlations, except for ADC measured at the first follow-up, reached significance. CONCLUSION: For the first time, the prognostic value of ADC maps measured in meningiomas before and at first follow-up after Gamma Knife SRS, was compared to simultaneously acquired DTI parameter maps. Quantities assessed from ADC maps present significant correlations to the volumetric meningioma response but are less effective than correlations with DTI parameters.

Bilateral Persistent Primitive Olfactory Arteries Observed During Resection of Olfactory Groove Meningioma: Technical Case Report.

BACKGROUND AND IMPORTANCE: Resection of olfactory groove meningiomas is challenging because of their close proximity with the anterior cerebral circulation. It is important to recognize the vascular variants in procedures at the anterior skull base because inadvertent maneuvers may result in the rupture of these arteries and unexpected bleeding. CLINICAL PRESENTATION: We reported a type 2 persistent primitive olfactory artery with a dural branch of the elongated anterior cerebral artery directly to the ethmoid region, visualized during the surgical removal of an olfactory groove meningioma. CONCLUSION: This is the first report of bilateral persistent primitive olfactory artery demonstrated by operative visualization and confirmed with vascular study. Understanding and recognizing the possible variations of this vascular anatomy is of great importance for anterior skull base surgeries.

Volumetric Growth and Growth Curve Analysis of Residual Intracranial Meningioma.

BACKGROUND: After meningioma surgery, approximately 1 in 3 patients will have residual tumor that requires ongoing imaging surveillance. The precise volumetric growth rates of these tumors are unknown. OBJECTIVE: To identify the volumetric growth rates of residual meningioma, growth trajectory, and factors associated with progression. METHODS: Patients with residual meningioma identified at a tertiary neurosurgery center between 2004 and 2020 were retrospectively reviewed. Tumor volume was measured using manual segmentation, after surgery and at every follow-up MRI scan. Growth rates were ascertained using a linear mixed-effects model and nonlinear regression analysis of growth trajectories. Progression was defined according to the Response Assessment in Neuro-Oncology (RANO) criteria (40% volume increase). RESULTS: There were 236 patients with residual meningioma. One hundred and thirty-two patients (56.0%) progressed according to the RANO criteria, with 86 patients being conservatively managed (65.2%) after progression. Thirteen patients (5.5%) developed clinical progression. Over a median follow-up of 5.3 years (interquartile range, 3.5-8.6 years), the absolute growth rate was 0.11 cm 3 per year and the relative growth rate 4.3% per year. Factors associated with residual meningioma progression in multivariable Cox regression analysis were skull base location (hazard ratio [HR] 1.60, 95% CI 1.02-2.50) and increasing Ki-67 index (HR 3.43, 95% CI 1.19-9.90). Most meningioma exhibited exponential and logistic growth patterns (median R 2 value 0.84, 95% CI 0.60-0.90). CONCLUSION: Absolute and relative growth rates of residual meningioma are low, but most meet the RANO criteria for progression. Location and Ki-67 index can be used to stratify adjuvant treatment and surveillance paradigms.

Impact of peritumoral brain edema on pre- and postoperative clinical conditions and on long-term outcomes in patients with intracranial meningiomas.

BACKGROUND: Peritumoral brain edema (PTBE) is a common complication related to intracranial meningiomas. In several studies, researchers have investigated the pathogenesis of PTBE, and the factors involved in its development in patients with intracranial meningiomas have been reported. However, very little is known about the clinical effect of PTBE on patients with intracranial meningiomas; therefore, a systematic examination of this matter is necessary. METHODS: In this study, we performed a systematic examination of 696 patients with primary intracranial meningiomas to assess the effect of preoperative PTBE on preoperative symptoms, neurological deficits and postoperative complications, and long-term outcomes with a follow-up period of 16.8 years. We performed a univariate analysis and multiple regression for specific outcomes and adjusted for other relevant clinical factors. RESULTS: A total of 627 (90.1%) patients were symptomatic preoperatively. One hundred eighty-eight (90.8%) patients with small to moderate PTBE and 125 (98.4%) patients with severe PTBE presented with symptoms significantly more often than the 314 (86.7%) patients without PTBE (p < 0.001, univariate analysis). Cognitive deficits, palsy and seizure were significantly more present, preoperatively, in patients with PTBE than in patients without PTBE (p < 0.001, univariate analysis). Two hundred fifty-five (36.6%) patients experienced surgical and systemic complications postoperatively. The complication rate was significantly higher in patients with PTBE; 41.5% for patients with small to moderate PTBE and 52.8% for patients with severe PTBE, compared to 28.2% of patients without PTBE (p < 0.001, univariate analysis). Furthermore, pre- and postoperative KPS scores were significantly lower in patients with PTBE (p < 0.001). Patients with PTBE required additional medical support significantly more often (p < 0.001) and had a significantly longer hospital stay (p < 0.001). The mortality rate was higher in patients with PTBE immediately after surgery and in the follow-up period; however, the difference was not significant. The neurological condition of all patients improved in the follow-up and did not show significant differences between patients with and without preoperative PTBE (p = 0.6361). Multiple logistic regression analyses revealed a significant association between PTBE and the presence of preoperative cognitive deficits, the incidences of seizure and postoperative complications, and low pre- and postoperative KPS scores. CONCLUSIONS: Preoperative PTBE significantly increased the incidences of specific preoperative symptoms, neurological deficits and postoperative complications in patients with intracranial meningiomas. After surgery, patients with preoperative PTBE required medical support significantly more often than patients without PTBE. However, all patients had favorable outcomes after surgery.

Intraoperative Flow Cytometry for the Evaluation of Meningioma Grade.

Meningiomas are the most frequent central nervous system tumors in adults. The majority of these tumors are benign. Nevertheless, the intraoperative identification of meningioma grade is important for modifying surgical strategy in order to reduce postoperative complications. Here, we set out to investigate the role of intraoperative flow cytometry for the differentiation of low-grade (grade 1) from high-grade (grade 2-3) meningiomas. The study included 59 patients. Intraoperative flow cytometry analysis was performed using the 'Ioannina Protocol' which evaluates the G0/G1 phase, S-phase, mitosis and tumor index (S + mitosis phase fraction) of a tumor sample. The results are available within 5 min of sample receipt. There were 41 grade 1, 15 grade 2 and 3 grade 3 meningiomas. High-grade meningiomas had significantly higher S-phase fraction, mitosis fraction and tumor index compared to low-grade meningiomas. High-grade meningiomas had significantly lower G0/G1 phase fraction compared to low-grade meningiomas. Thirty-eight tumors were diploids and twenty-one were aneuploids. No significant difference was found between ploidy status and meningioma grade. ROC analysis indicated 11.4% of tumor index as the optimal cutoff value thresholding the discrimination between low- and high-grade meningiomas with 90.2% sensitivity and 72.2% specificity. In conclusion, intraoperative flow cytometry permits the detection of high-grade meningiomas within 5 min. Thus, surgeons may modify tumor removal strategy.

High definition 4K-three-dimensional exoscope for removal of a C1-C2 meningioma: Technical case report.

In recent years, the exoscope has been proposed as an alternative to the microscope when a magnified view of the surgical field is required in spinal surgery. We present a case of a 52-year-old patient in which a meningioma in the upper cervical spine (C1-C2) was removed using a 4K-three-dimensional (3D) exoscope. The advantages of surgical removal of an intradural spinal tumor using an exoscope are illustrated, focusing mainly on vision quality and ergonomics. In addition, some technical details regarding the operating room setup are provided. Based on this experience, a 4K-3D exoscope can be useful for spinal tumor surgery when high magnification of anatomical details is required, allowing the surgeon to operate in a comfortable position throughout the surgical procedure.

Clinical outcomes after microsurgical resection of giant lateral ventricular meningiomas.

Giant lateral ventricular meningiomas (LVMs), with the largest diameter of at least 5 cm, form a distinct subset. The incidence of giant LVMs is considered to be relatively low. Here, we evaluated clinical characteristics, and clinical outcomes after microsurgical resection, especially functional outcomes and morbidity of giant LVMs. We retrospectively reviewed 49 patients with LVMs, including 18 giant LVMs from 2012 to 2020. And we analyzed clinical, histopathological, surgical, and outcome data at our institution. Giant LVMs were most commonly present in the fourth decade of patients with the male-to-female ratio of 1:2. The most common subtypes were transitional and fibrous. Most lesions were resected via the temporal or parieto-occipital approach in our series. The median volume of blood loss was higher in the giant group (900 vs. 600 ml, p = 0.02). Meanwhile, the median length of hospital stay was prolonged for giant LVMs (20.5 vs. 16.0 days, p < 0.01). The proportion of discharged functional deterioration was higher in giant LVMs (38.9% vs. 6.5%, p = 0.02). However, there was no statistical significance between functional deterioration and tumor size at long-term follow-up (p = 0.28). Giant LVMs patients suffered from neurological and regional complications more commonly, particularly from a postoperative hematoma (4/18 vs. 1/31), and hydrocephalus (2/18 vs. 0/31). Patients with giant LVMs had a high incidence of immediate functional deterioration after microsurgery, and there was no difference in functional deterioration between the giant and non-giant LVMS during long-term follow-up. Microsurgery entails a higher complication rate in giant LVMs. We need to pay special attention to preventing postoperative hematoma and hydrocephalus.