Preoperative neuroimaging findings as a predictor of the surgical plane of cleavage: prospective study of 100 consecutive cases of intracranial meningioma

Improved quantification of tumor adhesion in meningiomas using MR elastography-based slip interface imaging

Meningiomas, the most prevalent primary benign intracranial tumors, often exhibit complicated levels of adhesion to adjacent normal tissues, significantly influencing resection and causing postoperative complications. Surgery remains the primary therapeutic approach, and when combined with adjuvant radiotherapy, it effectively controls residual tumors and reduces tumor recurrence when complete removal may cause a neurologic deficit. Previous studies have indicated that slip interface imaging (SII) techniques based on MR elastography (MRE) have promise as a method for sensitively determining the presence of tumor-brain adhesion. In this study, we developed and tested an improved algorithm for assessing tumor-brain adhesion, based on recognition of patterns in MRE-derived normalized octahedral shear strain (NOSS) images. The primary goal was to quantify the tumor interfaces at higher risk for adhesion, offering a precise and objective method to assess meningioma adhesions in 52 meningioma patients. We also investigated the predictive value of MRE-assessed tumor adhesion in meningioma recurrence. Our findings highlight the effectiveness of the improved SII technique in distinguishing the adhesion degrees, particularly complete adhesion. Statistical analysis revealed significant differences in adhesion percentages between complete and partial adherent tumors (p = 0.005), and complete and non-adherent tumors (p<0.001). The improved technique demonstrated superior discriminatory ability in identifying tumor adhesion patterns compared to the previously described algorithm, with an AUC of 0.86 vs. 0.72 for distinguishing complete adhesion from others (p = 0.037), and an AUC of 0.72 vs. 0.67 for non-adherent and others. Aggressive tumors exhibiting atypical features showed significantly higher adhesion percentages in recurrence group compared to non-recurrence group (p = 0.042). This study validates the efficacy of the improved SII technique in quantifying meningioma adhesions and demonstrates its potential to affect clinical decision-making. The reliability of the technique, coupled with potential to help predict meningioma recurrence, particularly in aggressive tumor subsets, highlights its promise in guiding treatment strategies.

Hemorrhagic cerebral venous infarction after vein injury during intraoperative lesion resection: incidence, hemorrhagic stages, risk factors and prognosis

Objective

Cerebral venous infarction (CVI) after vein injury during intraoperative lesion resection is associated with intracranial hemorrhage. We conducted this study to identify the incidence, clinical and imaging features, and prognosis of hemorrhage CVI.

Methods

We performed a retrospective analysis of patients with confirmed CVI after vein injury who underwent craniotomy in our hospital. Postoperative clinical symptoms were observed, and imaging features were compared between patients with and without intracranial hemorrhages through CT examination. Variables were analyzed using univariate and multivariate regression analyses.

Results

Among 2,767 patients who underwent craniotomy, 93 cases of injured veins were identified intraoperatively. Hemorrhagic CVI was found in 38% (35/93). Multivariate analysis revealed that midline approach, meningioma, postoperative seizures, disorders of consciousness and interval in hours < 72 h were identified as predictors of hemorrhagic CVI. After 3 months of follow-up, the prognosis was poor in 15 cases (16%, 15/93), including death (two cases), vegetative survival (four cases), and severe disability (nine cases).

Conclusions

Hemorrhagic CVI, as a critical complication after venous injury, can have disastrous consequences. Do not injure known veins intraoperatively. In case of injury, requisite remedial measures should be adopted during and after surgery.

Dural and calvarial metastasis of thyroid follicular carcinoma mimicking Sindou type 6 parafalcine meningioma

ABSTRACT

Fifty-two years, NID type-2 diabetic female was admitted with progressive headache, enlarging, pulsatile midline mass, dizziness, and numbness of extremities. Physical examination revealed only hypoesthesia in the upper left extremity C7-dermatome. Preoperative computed tomography revealed eroded parafalcian dural mass and caused a round 7 cm calvarial defect over the superior sagittal sinus (SSS) and another left parietal 1.2 cm satellite mass. Magnetic resonance imaging revealed an extra-axial, diffuse heterogeneous gadolinium-enhanced, well-circumscribed lesion invading the SSS and Trolard veins (bilaterally). Supratotal resection 1 cm from the tumor borders was performed, histopathology suggested papillary thyroid carcinoma follicular variant. The euthyroid patient underwent total thyroidectomy, and final pathology revealed invasive TFC. 5-year follow-up was uneventful without recurrence or new metastasis. Parafalcian meningioma classification was reviewed for the best surgical approach. The definitive diagnosis of meningioma should be established with histopathological analysis. TFC should be included in the differential diagnosis in cases of extra-axial tumors.

Preoperative surgical risk assessment of meningiomas: a narrative review based on MRI radiomics

Meningiomas are one of the most common intracranial primary central nervous system tumors. Regardless of the pathological grading and histological subtypes, maximum safe resection is the recommended treatment option for meningiomas. However, considering tumor heterogeneity, surgical treatment options and prognosis often vary greatly among meningiomas. Therefore, an accurate preoperative surgical risk assessment of meningiomas is of great clinical importance as it helps develop surgical treatment strategies and improve patient prognosis. In recent years, an increasing number of studies have proved that magnetic resonance imaging (MRI) radiomics has wide application values in the diagnostic, identification, and prognostic evaluations of brain tumors. The vital importance of MRI radiomics in the surgical risk assessment of meningiomas must be apprehended and emphasized in clinical practice. This narrative review summarizes the current research status of MRI radiomics in the preoperative surgical risk assessment of meningiomas, focusing on the applications of MRI radiomics in preoperative pathological grading, assessment of surrounding tissue invasion, and evaluation of tumor consistency. We further analyze the prospects of MRI radiomics in the preoperative assessment of meningiomas angiogenesis and adhesion with surrounding tissues, while pointing out the current challenges of MRI radiomics research.

The Pierre Wertheimer Neurological and Neurosurgical Hospital in Lyon: history of its development and contributions to neurosurgery

At the end of the 1950s, at the direction of Pierre Wertheimer, the first French professor of neurosurgery, the treatment of neurological and neurosurgical diseases for Lyon's 2 million people was concentrated in a single center functioning as not only a hospital but also a campus for neuroscience. The ideas behind the structure revolve around concepts such as spatial unity, comprehensive specialized fields, a critical mass of patients, a structured training program, and essential cross-communication between areas in the same field. Through several generations of doctors, researchers, and professors, the Pierre Wertheimer Neurological and Neurosurgical Hospital in Lyon (NHL) has had an important impact on clinical practice, fundamental neuroscientific research, and specialist training. Under Wertheimer's stewardship, functional neurosurgery became one of the fields of excellence at the NHL with contributions in pain surgery and physiology but also epilepsy surgery and surgery for spasticity. Typically, these contributions were the result of the collaboration of separate teams, ultimately laying the groundwork for a neuroscientific doctoral school. The large mass of patients treated at the NHL provided opportunities for other, more isolated insights, such as the classification of pineal tumors and contributions to interventional neuroradiology. The present work endeavors to illustrate the contributions of the NHL to neuroscience and discuss the background allowing for their occurrence.

Risk factors influencing cerebral venous infarction after meningioma resection

BACKGROUND

Cerebral venous infarction (CVI) is a serious complication after meningioma resection. The risk factors of postoperative cerebral venous infarction after surgical resection of meningioma can be determined through large samples and this study can add evidence to the literature.

METHODS

The clinical and imaging data of 1127 patients with intracranial meningiomas who underwent resection in our hospital were retrospectively collected and analyzed. CVI was evaluated by postoperative imaging and clinical manifestations. Univariate and multivariate analyses were performed to identify risk factors associated with CVI.

RESULTS

Overall, 4.7% (53/1127) of patients experienced CVI after meningioma resection. Multivariate analysis revealed superficial meningioma, moderate to severe peritumoral edema, peritumoral critical vein and WHO grade II-III as independent predictors of a postoperative CVI. After timely intervention, the symptoms were clearly alleviated in one month, and the prognosis was good, but injury to key veins could cause irreversible neurological disorders.

CONCLUSIONS

Intraoperative protection of veins is the primary way to prevent CVI. The present study identified several significant and independent risk factors for postoperative venous infarction, thereby enabling the identification of high-risk patients who require special attention during clinical and surgical management.

Evaluation of Surgical Cleavage Plane by Preoperative Magnetic Resonance Imaging Findings in Adult Intracranial Meningiomas

(1) Background: Meningiomas are usually benign encapsulated intracranial tumors with well-defined borders that offer a high chance of cure with complete removal. The aim of this study was to evaluate the association between preoperative MRI features and surgical plane of cleavage. (2) Materials and Methods: This was a cross-sectional observational study conducted in the Department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University. Data were recorded from 48 study participants with confirmed intracranial meningioma and analyzed by IBM SPSS (version 23). (3) Results: The highest incidence of intracranial meningioma was observed in the third decade of life of our study participants. The female to male ratio was 1.82:1. The most common location of meningiomas was convexity (29.16%), sphenoid wing (22.91%), parasagittal (20.83%), and falcine (14.58%). Most of the patients (68.8%) had medium-sized tumors, and 75.0% exhibited hyperintense signal change in the tumor parenchyma on T2-weighted imaging. One-third (33.3%) of patients were characterized as no edema, focal edema, and lobar/hemispheric edema. There was no statistically significant association between tumor size and types of surgical cleavage plane. Different signal intensities of tumor parenchyma, as well as types of peritumoral edema, showed no statistically significant association with surgical cleavage plane (p > 0.05). (4) Conclusion: There was no association among the size of the tumor, extent of peritumoral edema, the intensity of the tumor on T2-weighted images, and the types of surgical cleavage plane. Future studies with larger sample sizes are required to find out more precise findings.

A new method for quantification and 3D visualization of brain tumor adhesion using slip interface imaging in patients with meningiomas

OBJECTIVES

To develop an objective quantitative method to characterize and visualize meningioma-brain adhesion using MR elastography (MRE)-based slip interface imaging (SII).

METHODS

This retrospective study included 47 meningiomas (training dataset: n = 35; testing dataset: n = 12) with MRE/SII examinations. Normalized octahedral shear strain (NOSS) values were calculated from the acquired MRE displacement data. The change in NOSS at the tumor boundary (ΔNOSS_bdy) was computed, from which a 3D ΔNOSS_bdy map of the tumor surface was created and the probability distribution of ΔNOSS_bdy over the entire tumor surface was calculated. Statistical features were calculated from the probability histogram. After eliminating highly correlated features, the capability of the remaining feature for tumor adhesion classification was assessed using a one-way ANOVA and ROC analysis.

RESULTS

The magnitude and location of the tumor adhesion can be visualized by the reconstructed 3D ΔNOSS_bdy surface map. The entropy of the ΔNOSS_bdy histogram was significantly different between adherent tumors and partially/completely non-adherent tumors in both the training (AUC: 0.971) and testing datasets (AUC: 0.900). Based on the cutoff values obtained from the training set, the ΔNOSS_bdy entropy in the testing dataset yielded an accuracy of 0.83 for distinguishing adherent versus partially/non-adherent tumors, and 0.67 for distinguishing non-adherent versus completely/partially adherent tumors.

CONCLUSIONS

SII-derived ΔNOSS_bdy values are useful for quantification and classification of meningioma-brain adhesion. The reconstructed 3D ΔNOSS_bdy surface map presents the state and location of tumor adhesion in a "clinician-friendly" manner, and can identify meningiomas with a high risk of adhesion to adjacent brain parenchyma.

KEY POINTS

• MR elastography (MRE)-based slip interface imaging shows promise as an objective tool to preoperatively discriminate meningiomas with a high risk of intraoperative adhesion. • Measurement of the change of shear strain at meningioma boundaries can provide quantitative metrics depicting the state of adhesion at the tumor-brain interface. • The surface map of tumor adhesion shows promise in assisting precise adhesion localization, using a comprehensible, "clinician-friendly" 3D visualization.

Novel method to evaluate the risk of tumor adhesions and post-operative hemorrhage of meningiomas using 320 row CT-DSA: A clinical research study

OBJECTIVE

Meningioma is an extra-axial tumor that forms adhesions toward the brain surface in the course of its growth. Predicting adhesions between the tumor and the brain surface leads to better predictions of surgical results. There are few studies on brain-tumor adhesions or postoperative hemorrhage. This study aimed to assess tumor vascularity of the dura and cerebral surface, and predict surgical outcomes using four-dimensional computed tomography angiography (4D CTA).

PATIENTS AND METHODS

Using a dynamic contrast CT, we conducted a retrospective study of 27 patients with convexity (n = 15), falx (n = 6), and parasagittal (n = 6) meningiomas treated in our hospital from January 2016 to September 2018. We set the region of interest on the dural layer and cerebral surface side of meningiomas and calculated the mean CT value in each region. Distribution of blood flow in the tumor was classified into two groups: A, which has a higher CT value of the dural side than that of the brain surface side at every timing, and B, which meets the criteria other than those in group A. Demographic data, preoperative characteristic images, and postoperative complications were compared between the groups.

RESULTS

Twelve and 15 patients were classified into groups A and B, respectively. The extent of adhesions against the cerebral cortex in group A was significantly less severe compared with that in group B (p = 0.038). The rate of postoperative hemorrhage occurrence in group B (53%) was significantly higher than that in group A (8%) (p = 0.04). There were no significant differences in the other preoperative characteristic images or perioperative parameters between groups A and B.

CONCLUSION

A 320-row dynamic contrast CT scanner can detect meningiomas with a high probability of severe adhesion toward the brain surface and postoperative intraparenchymal hematoma.

Peritumoral Edema Relative to Meningioma Size Predicts Functional Outcomes after Resection in Older Patients

BACKGROUND

Resection of meningiomas in older adults is associated with increased complications and postoperative functional deficits. Extent of peritumoral edema (PTE), which has been associated with surgical prognosis, may represent a preoperative risk marker for poorer outcomes in older adults.

OBJECTIVE

To quantitatively evaluate the relationship between preoperative PTE and postresection outcomes in older meningioma patients.

METHODS

One hundred twelve older meningioma patients (age ≥ 60) with evidence of PTE on MRI were reviewed. Extent of PTE, measured as a ratio of edema to tumor volume (edema index, EI) using semiautomatic image-processing software, was correlated with postresection outcomes. Other preoperative factors were included as covariates in multivariate analyses. Results were compared to matched nonedema older patients. Receiver operating characteristic (ROC) curve analysis was performed to identify cut-off EI values to predict postoperative outcomes.

RESULTS

EI was associated with functional decline (as measured by Karnofsky Performance Status, KPS) at 6 mo, 1, 2 yr, and most recent follow-up (Ps < .05), but not among the nonedema matched patients. Seizure or prior stroke additionally trended towards increasing the likelihood of lower KPS at 2 yr (odds ratio = 3.06) and last follow-up (odds ratio = 5.55), respectively. ROC curve analysis found optimal cut-off values for EI ranging from 2.01 to 3.37 to predict lower KPS at each follow-up interval. Sensitivities ranged from 60% to 80%, specificities from 78% to 89%, and positive and negative predictive values from 38% to 58% and 80% to 97%.

CONCLUSION

Preoperative PTE may represent a significant marker of poor functional outcome risk in older adults and provides a quantitative measurement to incorporate into surgical decision-making.

Surgical treatment of meningiomas located in the rolandic area: the role of navigated transcranial magnetic stimulation for preoperative planning, surgical strategy, and prediction of arachnoidal cleavage and motor outcome

OBJECTIVE

Surgical treatment of convexity meningiomas is usually considered a low-risk procedure. Nevertheless, the risk of postoperative motor deficits is higher (7.1%-24.7% of all cases) for lesions located in the rolandic region, especially when an arachnoidal cleavage plane with the motor pathway is not identifiable. The authors analyzed the possible role of navigated transcranial magnetic stimulation (nTMS) for planning resection of rolandic meningiomas and predicting the presence or lack of an intraoperative arachnoidal cleavage plane as well as the postoperative motor outcome.

METHODS

Clinical data were retrospectively collected from surgical cases involving patients affected by convexity, parasagittal, or falx meningiomas involving the rolandic region, who received preoperative nTMS mapping of the motor cortex (M1) and nTMS-based diffusion tensor imaging (DTI) fiber tracking of the corticospinal tract before surgery at 2 different neurosurgical centers. Surgeons' self-reported evaluation of the impact of nTMS-based mapping on surgical strategy was analyzed. Moreover, the nTMS mapping accuracy was evaluated in comparison with intraoperative neurophysiological mapping (IONM). Lastly, we assessed the role of nTMS as well as other pre- and intraoperative parameters for predicting the patients' motor outcome and the presence or absence of an intraoperative arachnoidal cleavage plane.

RESULTS

Forty-seven patients were included in this study. The nTMS-based planning was considered useful in 89.3% of cases, and a change of the surgical strategy was observed in 42.5% of cases. The agreement of nTMS-based planning and IONM-based strategy in 35 patients was 94.2%. A new permanent motor deficit occurred in 8.5% of cases (4 of 47). A higher resting motor threshold (RMT) and the lack of an intraoperative arachnoidal cleavage plane were the only independent predictors of a poor motor outcome (p = 0.04 and p = 0.02, respectively). Moreover, a higher RMT and perilesional edema also predicted the lack of an arachnoidal cleavage plane (p = 0.01 and p = 0.03, respectively). Preoperative motor status, T2 cleft sign, contrast-enhancement pattern, and tumor volume had no predictive value.

CONCLUSIONS

nTMS-based motor mapping is a useful tool for presurgical assessment of rolandic meningiomas, especially when a clear cleavage plane with M1 is not present. Moreover, the RMT can indicate the presence or absence of an intraoperative cleavage plane and predict the motor outcome, thereby helping to identify high-risk patients before surgery.

The Predictive Value of Conventional Magnetic Resonance Imaging Sequences on Operative Findings and Histopathology of Intracranial Meningiomas: A Prospective Study

Background

Previous studies have tried to relate magnetic resonance (MR) characteristics of meningiomas with its intraoperative features and histopathology with varying results. This is a prospective study to assess the independent predictive value of conventional MR signals [T1, T2, and fluid attenuated inversion recovery (FLAIR)] in relation to consistency, vascularity, operative plane, Simpson excision, and histopathology of intracranial meningiomas in a multivariate model.

Materials and Methods

Seventy patients underwent T1, T2, FLAIR, postcontrast sequences followed by excision of their meningiomas. Tumor signal intensity in various sequences was studied in relation to the above-mentioned variables. Multivariate analysis to find their independent association was performed.

Results

T1 images showed no correlation with any of the variables. FLAIR hypointensity and inhomogeneous enhancement had significant association with tumor hardness. FLAIR hypointense tumors were associated with low vascularity. FLAIR hypointensity, skull base location, and recurrence were significantly related to the subpial or mixed operative plane. The meningioma-brain interface on T2 sequence was significantly related to the operative plane. Only skull base location had significant impact on the extent of excision. T2 and FLAIR hypointensity had significant association with fibroblastic or psammomatous meningiomas. On multivariate analysis, FLAIR hypointensity and skull base location had a significant independent relationship with suboptimal operative plane, while skull base location had association with the extent of excision. Among MRI sequences, FLAIR hypointensity showed high specificity (94%) in predicting the suboptimal operative plane.

Conclusions

FLAIR hypointensity of meningiomas appears to have a significant independent association with the suboptimal operative plane with high specificity.

Modeling of connective tissue damage for blunt dissection of brain tumor in neurosurgery simulation

We introduce a new model for connective tissue damage in blunt dissection, which is a very important process in neurosurgery simulation. Specifically, the tool-tissue interaction between the instrument and connective tissue is incorporated into the model of connective tissue damage. This damage develops with the evolution criterion due to the effect of the external load. The tetrahedral mesh in the soft tissue model is removed for the representation of rupture as the damage accumulates to the threshold value. Analysis and experiments show that the connective tissue damage model provides stable, visually realistic results for the simulation of the connective tissue rupture process. The stiffness of the connective tissue decreases as the damage accumulates. The proposed model for connective tissue damage was incorporated into the development of a neurosurgery simulator, in which blunt dissection of a brain tumor was simulated.

Risk of Developing Postoperative Deficits Based on Tumor Location after Surgical Resection of an Intracranial Meningioma

Object  Meningiomas occur in various intracranial locations. Each location is associated with a unique set of surgical nuances and risk profiles. The incidence and risk factors that predispose patients to certain deficits based on tumor locations are unclear. This study aimed to determine which preoperative factors increase the risk of patients having new deficits after surgery based on tumor location for patients undergoing intracranial meningioma surgery. Methods  Adult patients who underwent primary, nonbiopsy resection of a meningioma at a tertiary care institution between 2007 and 2015 were retrospectively reviewed. Stepwise multivariate logistic regression analyses were used to identify associations with postoperative deficits based on tumor location. Results  Postoperatively, from the 761 included patients, there were 39 motor deficits (5.1%), 23 vision deficits (3.0%), 19 language deficits (2.5%), 27 seizures (3.5%), and 26 cognitive deficits (3.4%). The factors independently associated with any postoperative deficits were preoperative radiation (hazard ratio [HR] [95% confidence interval, CI] 3.000 [1.346-6.338], p  = 0.008), cerebellopontine angle tumors (HR [95% CI] 2.126 [1.094-3.947], p  = 0.03), Simpson grade 4 resections (HR [95% CI] 2.000 [1.271-3.127], p  = 0.003), preoperative motor deficits (HR [95% CI] 1.738 [1.005-2.923], p  = 0.048), preoperative cognitive deficits (HR [95% CI] 2.033 [1.144-3.504], p  = 0.02), and perioperative pulmonary embolisms (HR [95% CI] 11.741 [2.803-59.314], p  = 0.0009). Conclusion  Consideration of the factors associated with postoperative deficits in this study may help guide treatment strategies for patients with meningiomas.

Further characterization of changes in axial strain elastograms due to the presence of slippery tumor boundaries

Elastography measures tissue strain, which can be interpreted under certain simplifying assumptions to be representative of the underlying stiffness distribution. This is useful in cancer diagnosis where tumors tend to have a different stiffness to healthy tissue and has also shown potential to provide indication of the degree of bonding at tumor-tissue boundaries, which is clinically useful because of its dependence on tumor pathology. We consider the changes in axial strain for the case of a symmetrical model undergoing uniaxial compression, studied by characterizing changes in tumor contrast transfer efficiency (CTE), inclusion to background strain contrast and strain contrast generated by slip motion, as a function of Young's modulus contrast and applied strain. We present results from a finite element simulation and an evaluation of these results using tissue-mimicking phantoms. The simulation results show that a discontinuity in displacement data at the tumor boundary, caused by the surrounding tissue slipping past the tumor, creates a halo of "pseudostrain" across the tumor boundary. Mobile tumors also appear stiffer on elastograms than adhered tumors, to the extent that tumors that have the same Young's modulus as the background may in fact be visible as low-strain regions, or those that are softer than the background may appear to be stiffer than the background. Tumor mobility also causes characteristic strain heterogeneity within the tumor, which exhibits low strain close to the slippery boundary and increasing strain toward the center of the tumor. These results were reproduced in phantom experiments. In addition, phantom experiments demonstrated that when fluid lubrication is present at the boundary, these effects become applied strain-dependent as well as modulus-dependent, in a systematic and characteristic manner. The knowledge generated by this study is expected to aid interpretation of clinical strain elastograms by helping to avoid misinterpretation as well as provide additional diagnostic criteria stated in the paper and stimulate further research into the application of elastography to tumor mobility assessment.

Slip interface imaging based on MR-elastography preoperatively predicts meningioma-brain adhesion

Purpose

To investigate the ability of slip interface imaging (SII), a recently developed magnetic resonance elastography (MRE)‐based technique, to predict the degree of meningioma–brain adhesion, using findings at surgery as the reference standard.

Materials and Methods

With Institutional Review Board approval and written informed consent, 25 patients with meningiomas >2.5 cm in maximal diameter underwent preoperative SII assessment. Intracranial shear motions were introduced using a soft, pillow‐like head driver and the resulting displacement field was acquired with an MRE pulse sequence on 3T MR scanners. The displacement data were analyzed to determine tumor–brain adhesion by assessing intensities on shear line images and raw as well as normalized octahedral shear strain (OSS) values along the interface. The SII findings of shear line images, OSS, and normalized OSS were independently and blindly correlated with surgical findings of tumor adhesion by using the Cohen's κ coefficient and chi‐squared test.

Results

Neurosurgeons categorized the surgical plane as extrapial (no adhesion) in 15 patients, mixed in four, and subpial (adhesion) in six. Both shear line images and OSS agreed with the surgical findings in 18 (72%) cases (fair agreement, κ = 0.37, 95% confidence interval [CI]: 0.05–0.69), while normalized OSS was concordant with the surgical findings in 23 (92%) cases (good agreement, κ = 0.86, 95% CI: 0.67–1). The correlation between SII predictions (shear line images, OSS, and normalized OSS) and the surgical findings were statistically significant (chi‐squared test, P = 0.02, P = 0.02, and P < 0.0001, respectively).

Conclusion

SII preoperatively evaluates the degree of meningioma–brain adhesion noninvasively, allowing for improved prediction of surgical risk and tumor resectability.

Level of Evidence: 1

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1007–1016.

Petroclival meningiomas: Magnetic resonance imaging factors predict tumor resectability and clinical outcome

OBJECTIVE

Despite advances in skull base surgery, surgical removal of petroclival meningiomas (PCM) still poses a considerable neurosurgical challenge with regard to postoperative morbidity and the patients' long-term outcome. Knowledge of imaging features for PCM that might help to predict common risk factors encountered with tumor resection preoperatively is limited. The aim of this study was to clarify whether MRI features of PCM might predict tumor resectability and clinical outcome.

METHODS

A retrospective analysis of 18 cases of PCM treated surgically in our department between 2007 and 2013 was performed. Following radiological tumor features were compared to the extent of tumor resection and the patients' outcome: a) tumor diameter, b) calcification, c) tumor margin towards the brainstem, d) presence of an arachnoidal cleavage plane, e) brainstem edema, f) brainstem compression and g) tumor signal intensity on T2WI.

RESULTS

There was an excellent correlation between tumor resectability and preoperative findings with regard to the presence or absence of an arachnoidal cleavage plane and an irregular tumor margin towards the brainstem. Additionally, the presence of brainstem edema was significantly related to surgical morbidity, whereas a high tumor intensity on T2WI correlated significantly with soft tumor consistency and/or vascularity encountered during surgery.

CONCLUSION

As demonstrated in our series, PCM with an irregular tumor margin and absence of an arachnoidal plane towards the brainstem should be considered a high-risk group. In these cases, especially when additional brainstem edema is present, limited resection of tumor may be aspired to avoid postoperative morbidity.

Long-term evaluation of the effect of hypofractionated high-energy proton treatment of benign meningiomas by means of (11)C-L-methionine positron emission tomography

PURPOSE

To determine if (11)C-L-methionine PET is a useful tool in the evaluation of the long-term effect of proton beam treatment in patients with meningioma remnant.

METHODS

Included in the study were 19 patients (4 men, 15 women) with intracranial meningioma remnants who received hypofractionated high-energy proton beam treatment. Patients were examined with (11)C-L-methionine PET and MRI prior to treatment and after 6 months, and 1, 2, 3, 5, 7 and 10 years. Temporal changes in methionine uptake ratio, meningioma volume, meningioma regrowth and clinical symptoms throughout the follow-up period were evaluated.

RESULTS

In 17 patients the tumour volume was unchanged throughout the follow-up. The methionine uptake ratio on PET decreased over the years in most patients. In two patients the tumour remnant showed progression on MRI. In these patients, prior to the volume increase on MRI, the methionine uptake ratio increased. One patient experienced transient clinical symptoms and showed radiological evidence of a radiation-induced reaction close to the irradiated field.

CONCLUSION

Proton beam treatment is a safe and effective treatment for achieving long-term growth arrest in meningioma remnants. Follow-up with (11)C-L-methionine PET may be a valuable adjunct to, but not a replacement for, standard radiological follow-up.

Pseudotumor-like syndrome and cerebrospinal fluid leak in meningiomas involving the posterior third of the superior sagittal sinus: report of 4 cases

Meningiomas that partially or completely occlude the superior sagittal sinus may create a pseudotumor-like syndrome in certain patients. These patients may have impaired CSF absorption as a result of higher proximal venous pressure. Higher pressures after resection may encumber adequate wound healing and worsen symptoms. Here, the authors present a small series of patients with meningiomas involving the posterior third of the superior sagittal sinus, with documented high intracranial pressure prior to surgery. This paper aims to address the proposed etiology of high intracranial pressure in these patients and its associated complications, including CSF leak, wound dehiscence, pressure-related headaches, and visual complaints. In this paper, the authors propose a management plan to avoid wound complications and pseudotumor-related complications. When considering surgical intervention for patients with compromise of the posterior third of the superior sagittal sinus, careful attention must be paid to addressing potentially elevated intracranial pressure perioperatively.

Slip Interface Imaging Predicts Tumor-Brain Adhesion in Vestibular Schwannomas

PURPOSE

To test the clinical feasibility and usefulness of slip interface imaging (SII) to identify and quantify the degree of tumor-brain adhesion in patients with vestibular schwannomas.

MATERIALS AND METHOD

S With institutional review board approval and after obtaining written informed consent, SII examinations were performed in nine patients with vestibular schwannomas. During the SII acquisition, a low-amplitude mechanical vibration is applied to the head with a pillow-like device placed in the head coil and the resulting shear waves are imaged by using a phase-contrast pulse sequence with motion-encoding gradients synchronized with the applied vibration. Imaging was performed with a 3-T magnetic resonance (MR) system in less than 7 minutes. The acquired shear motion data were processed with two different algorithms (shear line analysis and calculation of octahedral shear strain [OSS]) to identify the degree of tumor-brain adhesion. Blinded to the SII results, neurosurgeons qualitatively assessed tumor adhesion at the time of tumor resection. Standard T2-weighted, fast imaging employing steady-state acquisition (FIESTA), and T2-weighted fluid-attenuated inversion recovery (FLAIR) imaging were reviewed to identify the presence of cerebral spinal fluid (CSF) clefts around the tumors. The performance of the use of the CSF cleft and SII to predict the degree of tumor adhesion was evaluated by using the κ coefficient and McNemar test.

RESULTS

Among the nine patients, SII agreed with the intraoperative assessment of the degree of tumor adhesion in eight patients (88.9%; 95% confidence interval [CI]: 57%, 98%), with four of four, three of three, and one of two cases correctly predicted as no adhesion, partial adhesion, and complete adhesion, respectively. However, the T2-weighted, FIESTA, and T2-weighted FLAIR images that used the CSF cleft sign to predict adhesion agreed with surgical findings in only four cases (44.4% [four of nine]; 95% CI: 19%, 73%). The κ coefficients indicate good agreement (0.82 [95% CI: 0.5, 1]) for the SII prediction versus surgical findings, but only fair agreement (0.21 [95% CI: -0.21, 0.63]) between the CSF cleft prediction and surgical findings. However, the difference between the SII prediction and the CSF cleft prediction was not significant (P = .103; McNemar test), likely because of the small sample size in this study.

CONCLUSION

SII can be used to predict the degree of tumor-brain adhesion of vestibular schwannomas and may provide a method to improve preoperative planning and determination of surgical risk in these patients.

Cavernous sinus meningiomas: imaging and surgical strategy

Cavernous sinus (CS) meningiomas which are by definition those meningiomas which originate from the parasellar region are difficult skull base tumors to deal with. For deciding the most appropriate surgical strategy, surgeons need detailed preoperative neuroimaging. The vicinity of the tumor with the vital and highly functional neurovascular structures, tumor extensions into the basal cisterns and skull base structures, and the arterial vascularization and venous drainage pathways, as they shape operative strategy, are important preoperative data to take into account. Thin section CT scan with bone windows, 3D spiral CT reconstruction, MRI, MR angiography, and DSA performed with selective arteriography including late venous phases give those required detailed informations about the tumor and its relation with neurovascular and bony structures. The type of craniotomy and complementary osteotomy and the usefulness of an extradural anterior clinoidectomy with unroofing the optic canal can be decided from preoperative neuroimaging. Data collected also help in determining whether extensive exposure of the middle cranial fossa is necessary to ensure substantial devascularization of the tumor and whether proximal control of the internal carotid artery (ICA) at its intrapetrosal portion might be useful. Study of the capacity of blood supply of the Willis circle is wise for deciding the need and way of performing an extra-intracranial bypass together with tumor removal. Currently the concept of operating only the tumors with extracavernous extensions and to limit resection to only their extracavernous portions is the most accepted way of treating these tumors. It was that strategy that was adopted in the senior author's 220-patient series.Radiosurgery or stereotactic fractionated radiotherapy may complement surgery or can be only reserved for growing remnants.

Prognostic implication of preoperative behavior changes in patients with primary high-grade meningiomas

High-grade meningiomas are rare extra-axial tumors, frequently causing brain invasion and prominent brain edema. Patients harboring high-grade meningiomas occasionally present with behavior changes. Data about frequency and prognostic importance of preoperative behavior changes in patients with high-grade meningiomas is missing. 86 patients with primary high-grade meningiomas were analyzed. Statistical analysis was performed to determine correlation of preoperative behavior changes with tumor location, preoperative brain edema, tumor cleavability, tumor grade, Ki67 proliferation index, and microscopic brain invasion. Survival analysis was performed. 30 (34.9%) patients presented with preoperative behavior changes. These changes were more frequent with male patients (P = 0.066) and patients older than 55 years (P = 0.018). They correlated with frontal location (P = 0.013), tumor size (P = 0.023), microscopic brain invasion (P = 0.015), and brain edema (P = 0.006). Preoperative behavior changes did not correlate with duration of symptoms, tumor cleavability, tumor malignancy grade, and Ki67 proliferation index. They were not significantly related to overall survival or recurrence-free survival of patients with primary high-grade meningiomas. Preoperative behavior changes are frequent in patients harboring primary high-grade meningiomas. They correlate with tumor size, microscopic brain invasion, and brain edema. Preoperative behavior changes do not predict prognosis in patients with primary high-grade meningiomas.

Factors affecting peritumoral brain edema in meningioma: special histological subtypes with prominently extensive edema

Various degrees of peritumoral brain edema (PTBE) are observed in patients with intracranial meningiomas. Factors affecting the occurrence of PTBE in intracranial meningioma were investigated. PTBE was investigated retrospectively for 110 patients with primary intracranial meningiomas. Predictive factors related to PTBE were analyzed, for example patient age, sex, magnetic resonance imaging features (contrast enhancement, tumor shape, tumor location, tumor volume), angiographical features (tumor stain, pial-cortical arterial supply, venous obstruction), and histopathological features (histological subtypes, mindbomb homolog 1 labeling index (MIB1-LI)). Histological subtypes were classified into World Health Organization (WHO) grade I common type (meningothelial, transitional, fibrous), grade I uncommon type, and grade II and III types. The extent of PTBE was assessed by calculation of the edema index (EI). PTBE was present in 53 cases (48 %). Male sex, heterogeneous enhancement, superficial location, tumor volume (≥10 cm(3)), remarkable tumor stain, pial supply, venous obstruction, malignant pathology, and MIB1-LI ≥4 % were correlated with PTBE in univariate analysis. Pial supply and remarkable tumor stain were correlated with PTBE in multivariate analysis. WHO grade I uncommon type had obviously higher EI than WHO grade I common type, and WHO grade II and III types (P < 0.001). Seven cases with prominently high EI (EI ≥10) were all WHO grade I uncommon type, including angiomatous, microcystic, secretory, and lymphoplasmacyte-rich meningioma. Prominently extensive PTBE might indicate the presence of WHO grade I uncommon type meningioma.

Radiological predictive factors for regrowth of residual benign meningiomas

The pre- and postoperative radiological predictive factors for the regrowth of residual benign meningiomas were investigated in 80 of 327 patients who underwent first surgery for intracranial meningioma, who met the following conditions: residual tumor observed on postoperative imaging, follow up for more than 5 years or until regrowth of the residual tumor, histological diagnosis of World Health Organization grade I, and no additional therapy performed within 1 month after surgery. These 80 patients were divided into those with no regrowth during the follow-up period (Group A, n = 54) and those with regrowth (Group B, n = 26), and the clinical characteristics and pre- and postoperative imaging findings were compared. Univariate analysis of factors influencing regrowth showed 6 factors were significant: tumor size ≥4 cm (p = 0.043), tumor volume ≥30 cm(3) (p = 0.026), presence of edema (p = 0.036), unclear brain-tumor interface (p < 0.001), presence of a pial-cortical blood supply (p = 0.031), and residual tumor volume ≥3.0 cm(3) (p < 0.001). Multivariate analysis showed only residual tumor volume ≥3.0 cm(3) was significant (p = 0.001). Generally, the significant imaging findings on univariate analysis suggest malignant meningioma. Similar findings may be observed even in grade I cases, and residual tumors may regrow in such cases. The possibility is particularly high if the residual tumor volume exceeds 3.0 cm(3), so early radiotherapy should be performed to prevent regrowth.

Convexity meningiomas: study of recurrence factors with special emphasis on the cleavage plane in a series of 100 consecutive patients

Object

Convexity meningiomas are expected to have a low recurrence rate given their classically “easy resectability.” Nonetheless, recurrence can occur. Factors playing a role in their recurrence are analyzed here, including the extent of resection and tumor histological type, among others, with a special emphasis on the cleavage plane.

Methods

The authors reviewed 100 cases of convexity meningiomas surgically treated between 1987 and 2001 with a median follow-up of 86 months (range 2–16 years). Preoperative and postoperative functional status, Simpson resection grade, histological type, and intraoperative surgical plane with pial vessel invasion were studied and correlated with the recurrence rate.

Results

The average tumor size was 3.6 ± 0.4 cm. The pre- and postoperative Karnofsky Performance Scale scores were 92.6 ± 4.6 and 97.9 ± 2.2, respectively. Ninety-five lesions were benign (WHO Grade I) and 5 were atypical (WHO Grade II). Ninety-one and 9 tumors were subjected to Simpson Grade 1 and 3 resections (three Grade 3a and six Grade 3b), respectively. Surgical deaths did not occur. After a mean follow-up of 7.2 years, 4 meningiomas recurred; 2 (2.2%) after Simpson Grade 1 resections and 2 after Simpson Grade 3 (3a and 3b) resections (22.2%; p = 0.0034). When just the subgroup of Simpson Grade 1/WHO Grade I was studied, the recurrence rate decreased to 1.2% (1 of 86 cases). The recurrence of WHO Grade I tumors was higher in the subpial group than in the extrapial group (p = 0.025). No difference in recurrence according to the cleavage plane was seen in the WHO Grade II subgroup (p = 0.361). As for the subpial group, no difference in recurrence was noted between the WHO Grade I and II subgroups (p = 0.608). Importantly, however, the extrapial subgroup of WHO Grade II lesions had a higher recurrence rate compared with its counterpart in the WHO Grade I subgroup (p = 0.005).

Conclusions

Pial and vascular invasion affect the recurrence rate in convexity meningioma surgery. The recurrence rate of WHO Grade I tumors was higher among those with a subpial plane of dissection than among those with an extrapial one. Histological type did not determine the degree of pial invasion in WHO Grade I and II lesions.

Mitotic count, brain invasion, and location are independent predictors of recurrence-free survival in primary atypical and malignant meningiomas: a study of 86 patients

BACKGROUND

Since precise diagnostic criteria for atypical and malignant meningiomas (AMMs) were provided for the first time in the 2000 World Health Organization (WHO) criteria, there is only sparse information about possible prognostic factors in the group of AMMs.

OBJECTIVE

To evaluate the prognostic significance of various histological and clinical parameters in AMMs, with an emphasis on location, mitotic count, brain invasion, and Ki67 labeling index.

METHODS

We analyzed 86 primary AMMs, 76 of which were atypical and 10 of which were malignant, diagnosed according to the 2000 WHO classification. Multivariate Cox survival analyses were performed.

RESULTS

High mitotic count, brain invasion, and the parasagittal-falcine location of the tumor were significantly associated with decreased recurrence-free survival in multivariate analysis. Brain invasion was present in 25 of 37 cases in which brain tissue was identified in the tumor specimens. When brain invasion was not included in the analysis because of the limited number of cases in which it could be assessed, high mitotic count, Ki67 index >4%, the presence of macronucleoli, and parasagittal-falcine location were significant predictors of shorter recurrence-free survival.

CONCLUSION

AMMs, as defined by 2000 WHO, are biologically heterogeneous. Recurrence-free survival can be further stratified by location and histological parameters, especially mitotic count, brain invasion, and Ki67 labeling index. Not only brain invasion, but also the presence or absence of brain tissue in surgical specimens should be reported, because the absence of brain invasion, when brain tissue is identified, provides very important positive prognostic information.

¹H-MRS of intracranial meningiomas: what it can add to known clinical and MRI predictors of the histopathological and biological characteristics of the tumor?

OBJECTIVE

The main goal of the present study was evaluation of proton magnetic resonance spectroscopy (¹H-MRS) in diagnosis of histopathologically aggressive intracranial meningiomas.

METHODS

Single-voxel ¹H-MRS of 100 intracranial meningiomas was performed before their surgical resection. Investigated metabolites included mobile lipids, lactate, alanine, N-acetylaspartate (NAA), and choline-containing compounds (Cho). According to criteria of World Health Organization (WHO) 82 meningiomas were assigned histopathological grade I, 11 grade II, and 7 grade III. The MIB-1 index varied from 0% to 27.3% (median, 1.6%). In 43 cases tight adhesion of the tumor to the pia mater or brain tissue was macroscopically identified at surgery. The consistency of 49 meningiomas was characterized as soft, 26 as hard, and 25 as mixed.

RESULTS

No one metabolic parameter had statistically significant association with histopathological grade and subtype, invasive growth, and consistency of meningioma. Univariate statistical analysis revealed greater ¹H-MRS-detected Cho content (P=0.0444) and lower normalized NAA/Cho ratio (P=0.0203) in tumors with MIB-1 index 5% and more. However, both parameters lost their statistical significance during evaluation in the multivariate model along with other clinical and radiological variables. It was revealed that non-benign histopathology of meningioma (WHO grade II/III) is mainly predicted by irregular shape (P=0.0076) and large size (P=0.0316), increased proliferative activity by irregular shape (P=0.0056), and macroscopically invasive growth by prominent peritumoral edema (P=0.0021).

CONCLUSION

While ¹H-MRS may be potentially used for the identification of meningiomas with high proliferative activity, it, seemingly, could not add substantial diagnostic information to other radiological predictors of malignancy in these tumors.

Brain surface motion imaging to predict adhesions between meningiomas and the brain surface

INTRODUCTION

"Brain surface motion imaging" (BSMI) is the subtraction of pulse-gated, 3D, heavily T2-weighted image of two different phases of cerebrospinal fluid (CSF) pulsation, which enables the assessment of the dynamics of brain surface pulsatile motion. The purpose of this study was to evaluate the feasibility of this imaging method for providing presurgical information about adhesions between meningiomas and the brain surface.

METHODS

Eighteen cases with surgically resected meningioma in whom BSMI was presurgically obtained were studied. BSMI consisted of two sets of pulse-gated, 3D, heavily T2-weighted, fast spin echo scans. Images of the systolic phase and the diastolic phase were obtained, and subtraction was performed with 3D motion correction. We analyzed the presence of band-like texture surrounding the tumor and judged the degree of motion discrepancy as "total," "partial," or "none." The correlation between BSMI and surgical findings was evaluated. For cases with partial adhesions, agreements in the locations of the adhesions were also evaluated.

RESULTS

On presurgical BSMI, no motion discrepancy was seen in eight cases, partial in six cases, and total in four cases. These presurgical predictions about adhesions and surgical findings agreed in 13 cases (72.2%). The locations of adhesions agreed in five of six cases with partial adhesions.

CONCLUSION

In the current study, BSMI could predict brain and meningioma adhesions correctly in 72.2% of cases, and adhesion location could also be predicted. This imaging method appears to provide presurgical information about brain/meningioma adhesions.

Peritumoral brain edema in benign meningiomas: correlation with clinical, radiologic, and surgical factors and possible role on recurrence

BACKGROUND

Approximately 60% of meningiomas are associated with peritumoral edema. Various causative factors have been discussed in the literature. The objective of this study was to investigate the correlation of PTBE with clinical, radiologic, and surgical aspects and recurrence of meningiomas.

METHODS

Sixty-one patients with benign meningiomas were chosen for surgical treatment by the Group of Brain Tumors and Metastasis of the Department of Neurosurgery. All patients underwent complete surgical resection (Simpson grades 1 and 2), and those with atypical and malignant histopathologic grades were excluded. Tumors located in the cavernous sinus, tuberculum sellae, foramen magnum, ventricles, and petroclival region were excluded.

RESULTS

Edema extension had a positive correlation with the higher recurrence rates (P = .042) and with the presence of irregular margins (P < .011) on bivariate analysis. Meningiomas with larger edema sizes also showed correlation with large meningiomas (P = .035), and the ones with smaller edema sizes correlated with the tentorial location (P = .032). Multivariate analysis showed an association between PTBE and the presence of seizures (odds ratio, 3.469), large meningiomas (odds ratio, 15.977), and for each cubic centimeter added to its size, the risk of edema increased 1.082 times (odds ratio).

CONCLUSION

Peritumoral brain edema may be related to the invading potential of meningiomas and may play a role in the recurrence potential of the tumor. As a consequence, it is reasonable to consider the presence of edema as an additional factor to be taken into account when mapping out strategies for the treatment of meningiomas.

[Imaging for the management of cavernous sinus meningiomas]

The treatment of cavernous sinus meningiomas remains controversial. However, at present, the general consensus is that only tumors with extracavernous extensions should be operated on and that resection is performed only on the extracavernous portions. Since these tumors are deep-seated and in the vicinity of vital and highly functional neurovascular structures, surgery remains difficult and dangerous. To achieve the gross total removal of the extracavernous extensions with minimal sequelae, the operative strategy must take into account the location of the tumor extension, not only in the basal cisterns but also into the skull base structures, the vascularization of the tumor with its feeders, as well as the venous drainage pathways. These anatomical and surgical data are collected from preoperative imaging, which includes CT-scan with bony windows and consecutive fine sections, MRI, angio-MR, and DSA angiography performed with selective arteriography including late venous phases. The operative plan must define the type of craniotomy and complementary osteotomy, the usefulness of an anterior clinoidectomy with skeletonization of the optic nerve, and determine whether extensive exposure of the cerebral middle fossa is necessary to ensure substantial devascularization of the tumor and proximal control of the internal carotid artery at its intrapetrosal portion. In addition, the possible need for an extra-intracranial bypass prior to tumor removal should be evaluated. The high number of neuroimaging investigations is the guarantee of surgical accuracy and safety.

Role of radiation therapy in treating intracranial meningiomas

Surgery is the mainstay for many patients with meningiomas, and it remains the standard. In large single-institution series, gross-total resection has been reported to achieve 5-, 10-, and 15-year recurrence-free survival rates of approximately 90, 80, and 70%, respectively. There are a growing number of series of patients with prolonged follow-up in which authors have evaluated fractionated external-beam radiation therapy (EBRT) either as an adjuvant to surgery for subtotally resected, recurrent, or higher-grade meningiomas, or as an alternative to surgery. The primary focus of this review is EBRT, but to lend perspective, a comparative analysis of surgery and radiosurgery is also provided.

INTRACRANIAL MENINGIOMA SURGERY IN THE NINTH DECADE OF LIFE

OBJECTIVE

The aims of this study are to assess the surgical outcome of elderly patients aged 80 years or more, to analyze the factors influencing postoperative course, and to propose a grading system to standardize the surgical indication of intracranial meningioma in the elderly.

METHODS

Between 1990 and 2005, we surgically treated 74 consecutive patients aged 80 years or more for intracranial meningiomas (47 women, 27 men; mean age, 82 yr; age range, 80–90 yr). The median follow-up period was 94 months (range, 15–147 mo). We retrospectively analyzed the factors influencing surgical outcome and retained the significant factors to form the Sex, Karnofsky Performance Scale, American Society of Anesthesiology Class, Location of Tumor, and Peritumoral Edema (SKALE) grading system.

RESULTS

There was no perioperative mortality, and the 1-year mortality rate was 9.4%. Postoperative mortality was lower in women with a Karnofsky Performance Scale score of 60 or greater, an American Society of Anesthesiology Class of 1 or 2, a noncritical tumor location, and a moderate or absent peritumoral edema. Patients with a SKALE score of more than 8 had an excellent outcome, whereas those with a SKALE score of less than 8 had a poor outcome. The rate of postoperative complications was 9.4%. Large tumors, critical locations, severe peritumoral edema, and total surgical excision were associated with a higher risk of postoperative complications.

CONCLUSION

Surgery of intracranial meningioma in elderly patients is feasible when the SKALE score is 8 or greater. Prospective studies are required to validate this grading system.

Falx meningiomas: surgical results and lessons learned from 68 cases

OBJECTIVE

The purpose of this study was to review the characteristics of falcine meningioma retrospectively and to identify the parameters associated with tumor recurrence.

METHODS

The analysis included; age, sex, extent of resection, and radiologic and pathologic findings. Falcine meningiomas were classified by location as anterior, middle, or posterior as described for parasagittal meningiomas.

RESULTS

Of the 795 meningioma patients treated between 1990 and 2004 at the authors' institution, 68 patients with meningiomas arising from the falx underwent craniotomies. There were 22 male and 46 female patients (1 : 2.1). Mean age was 55 years and ranged from 14 to 77 years. Locations of falcine meningioma were; the anterior third in 33 cases, middle in 20, and posterior in 15. Mean tumor volume was 42 cc and ranged from 4 to 140 cc. In 58 of the 68 patients tumors were totally removed. Additional surgery for recurrence was performed in 6 patients over 15 years. Of these 6 patients, only two patients underwent gross total tumor resection at first operation; the other four underwent subtotal tumor resection. Based on pathologic reports, the largest tumor subtype was transitional. There were four patients with a high grade tumor-three atypical and one anaplastic meningioma. Of the 68 patients, 59 achieved a good outcome (no neurological deficit or recurrence), six had temporary complications, two suffered new permanent postoperative deficits, and the remaining one died due to severe brain swelling despite postoperative intensive care. Extent of surgical resection was found to be significantly related to tumor recurrence.

CONCLUSION

Falcine meningioma accounted for 8.5% of intracranial meningiomas and the transitional meningioma was the most common subtype of falcine meningioma. Gross total resection of tumor was the single most important predictor of an improved surgical outcome.

Morbidity in 201 patients with small sized meningioma treated by microsurgery

BACKGROUND

The management of patients with small, often asymptomatic meningiomas is controversial and includes observation, microsurgery (MS) and stereotactic radiosurgery (SRS). The purpose of this retrospective study was to analyze the morbidity and the extent of removal after MS for small (< or =3 cm) intracranial meningiomas and compare these results to those of SRS reported in the literature.

METHODS

All patients with an intracranial meningioma with a maximum diameter up to 3 cm operated on in our institution over a 10 year period (1992-2002) were included in the study and retrospectively analyzed. Patients were grouped into asymptomatic and symptomatic and according to tumor location as: group I (cranial vault, parasagittal, lateral sphenoid), group II (falx, frontobasal, medial sphenoid, parasellar and tentorial), group III (cavernous sinus, petroclival, petrosal, CPA and foramen magnum).

FINDINGS

There were a total of 201 patients, of whom 102 were asymptomatic and 99 were symptomatic. The overall risk of permanent neurological morbidity was 4.9% in asymptomatic and 23.2% in symptomatic patients. The combined risk in asymptomatic and symptomatic patients was 5.4% in group I, 11.5% in group II, and 39.9% in group III lesions. Radical removal was achieved in all patients in group I, in 93.7% of group II, and 80% of group III lesions. There was no disease related mortality.

CONCLUSIONS

MS provides excellent efficacy and morbidity results in groups I and II meningiomas, especially in asymptomatic patients and might therefore be considered the first choice of treatment for these patients. The results of MS in group III were worse than those of SRS reported in the literature.

Vascular Lesions of the Skull Base: Endovascular Prospective for the Otolaryngologist

With continual advances being made in endovascular equipment and techniques, the role that these image-guided, minimally invasive therapies play in the multidisciplinary management of vascular lesions of the skull base will probably continue to expand. The introduction of emerging technologies, including the development and implementation of implantable bioactive devices such as drug-eluting stents, bioactive embolic coils, and bioactive particulate embolic materials, will provide an increasing array of options for these patients. This article has reviewed the basic concepts of embolization and revascularization for vascular lesions of the skull base encountered by the practicing otolaryngologist. These concepts can provide a framework for collaboration between the otolaryngologist and neuroendovascular operator in a cooperative approach to these patients. The importance of detailed knowledge of the vascular anatomy of the skull base when dealing with these lesions, the concept of dangerous anastomoses, several clinically useful classification schemes for these lesions, and basic endovascular techniques of embolization and revascularization have been highlighted.

Analysis of the influence of the variable size on the characteristics and behavior of meningiomas

Seventy-two patients submitted to meningioma surgery at Pedro Hispano Hospital from 1997 to 2001 were reviewed to analyze the association between size (largest diameter of the lesion obtained from imaging examinations) and other variables regarding the biological behavior and clinical outcome of these patients. Statistically significant associations were found between tumor size and location, type of first symptom, type of physical examination, histological grade, surgical complications, postoperative CSF bursae and the need for blood transfusion. Patient's age, gender, duration of first symptom, clinical status at discharge and persistent complaints were not associated to tumor size. There was a trend towards a statistically significant association between tumor size and both grade of resection and persistent deficits. The causes and implications of the findings are discussed. Tumor size is a parameter that may interfere with the neurosurgeon's capacity to treat these patients as well as with their recovery.