Proposed grading system to predict the extent of resection and outcomes for cranial base meningiomas

Angiographic Features of Meningiomas Predicting Extent of Preoperative Embolization

BACKGROUND AND OBJECTIVES

Preoperative embolization is used as an endovascular adjunct to surgical resection of meningiomas. However, there is no standardized system to assess the efficacy or extent of embolization during the embolization procedure. We sought to establish a purely angiographic grading system to facilitate consistent reporting of the outcome of meningioma embolization and to characterize the anatomic and other features of meningiomas that predict the degree of devascularization achieved through preoperative embolization.

METHODS

We identified patients with meningiomas who underwent preoperative cerebral angiography and subsequent resection between 2015 and 2021. Demographic, clinical, and imaging data were collected in a research registry. We defined an angiographic devascularization grading scale as follows: grade 0 for no embolization, 1 for partial embolization, 2 for majority embolization, 3 for complete external carotid artery embolization, and 4 for complete embolization.

RESULTS

Eighty consecutive patients were included, 60 of whom underwent preoperative tumor embolization (20 underwent angiography with an intention to treat but ultimately not embolization). Embolized tumors were larger (59.0 vs 35.9 cc; P = .03). Gross total resection, length of stay, and complication rates did not differ among groups. The distribution of arterial feeders differed significantly across tumors in a location-specific manner. Both the tumor location and the identity of arterial feeders were predictive of the extent of embolization. Anterior midline meningiomas were associated with internal carotid (ophthalmic, ethmoidal) supply and lower devascularization grades (P = .03). Tumors fed by meningeal feeders (convexity, falcine, lateral sphenoid wing) were associated with higher devascularization grades (P < .01). The procedural complication rate for tumor embolization was 2.5%.

CONCLUSION

Angiographic outcomes can be graded to indicate the extent of tumor embolization. This system may facilitate consistency of reported angiographic results. In addition, arterial feeders vary in a manner predicted by tumor location, and these patterns correlate with typical degrees of devascularization achieved in those tumor locations.

Role of risk factors, scoring systems, and prognostic models in predicting the functional outcome in meningioma surgery: multicentric study of 552 skull base meningiomas

Despite the importance of functional outcome, only a few scoring systems exist to predict neurologic outcome in meningioma surgery. Therefore, our study aims to identify preoperative risk factors and develop the receiver operating characteristics (ROC) models estimating the risk of a new postoperative neurologic deficit and a decrease in Karnofsky performance status (KPS). A multicentric study was conducted in a cohort of 552 consecutive patients with skull base meningiomas who underwent surgical resection from 2014 to 2019. Data were gathered from clinical, surgical, and pathology records as well as radiological diagnostics. The preoperative predictive factors of functional outcome (neurologic deficit, decrease in KPS) were analyzed in univariate and multivariate stepwise selection analyses. Permanent neurologic deficits were present in 73 (13.2%) patients and a postoperative decrease in KPS in 84 (15.2%). Surgery-related mortality was 1.3%. A ROC model was developed to estimate the probability of a new neurologic deficit (area 0.74; SE 0.0284; 95% Wald confidence limits (0.69; 0.80)) based on meningioma location and diameter. Consequently, a ROC model was developed to predict the probability of a postoperative decrease in KPS (area 0.80; SE 0.0289; 95% Wald confidence limits (0.74; 0.85)) based on the patient's age, meningioma location, diameter, presence of hyperostosis, and dural tail. To ensure an evidence-based therapeutic approach, treatment should be founded on known risk factors, scoring systems, and predictive models. We propose ROC models predicting the functional outcome of skull base meningioma resection based on the age of the patient, meningioma size, and location and the presence of hyperostosis and dural tail.

Correlation of Surgical Outcomes of Petroclival Meningiomas with Clinicoradiologic Parameters and Molecular and Chromosomal Alterations

OBJECTIVE

To identify clinical, radiologic, intraoperative, histopathologic, and molecular factors that might affect the surgical outcome of petroclival meningiomas.

METHODS

Medical records of 53 cases of petroclival meningiomas operated from 2003 to 2021 were reviewed for clinicoradiologic and molecular factors that were correlated with extent of resection.

RESULTS

Modified Dolenc-Kawase anterior transpetrous rhomboid (44, 83.0%) was the most commonly used approach, followed by retrosigmoid (2, 3.8%) and combined (7, 13.2%) approaches. Hypointense tumors on T2-weighted magnetic resonance imaging (odds ratio [OR] 5.85; 95% confidence interval [CI] 1.70-20.41) and presence of brainstem edema (OR 4.53; 95% CI 1.36-15.12) were found to be significant factors increasing the likelihood of subtotal resection (STR; P = 0.004 and P = 0.011, respectively). In the presence of both tumor T2 hypointensity and brainstem edema, there was a significant increase in the likelihood of STR (P = 0.001; OR 25; 95% CI 3.52-177.48). Of the 16 cases for which molecular analysis was performed, no specimen was found to have pTERT, AKT-1 E17K, and SMO L412F and W535L mutations. All (100%) the patients harboring H3K27me3 loss and/or hemizygous CDKN2A deletion had cavernous sinus extension compared with 62.5% of patients without H3K27me3 loss and 72.7% with hemizygous CDKN2A retention. Similarly, hemizygous CDKN2A deletion and H3K27me3 loss were associated with an increase in the rate of brainstem edema from 27.3% to 60% and 25% to 50%, respectively.

CONCLUSIONS

T2 hypointense tumor and brainstem edema on preoperative imaging are significant predictors of STR. H3K27me3 loss and hemizygous CDKN2A deletion may be associated with cavernous sinus extension, suggesting their role in tumor spread.

Decreased Craniocervical CSF Flow in Patients with Normal Pressure Hydrocephalus: A Pilot Study

BACKGROUND AND PURPOSE

Normal pressure hydrocephalus is characterized by systolic peaks of raised intracranial pressure, possibly due to a reduced compliance of the spinal CSF spaces. This concept of a reduced spinal CSF buffer function may be reflected by a low cervical CSF outflow from the cranium. The aim of this study was to investigate craniospinal CSF flow rates by phase-contrast MR imaging in patients with normal pressure hydrocephalus.

MATERIALS AND METHODS

A total of 42 participants were included in this prospective study, consisting of 3 study groups: 1) 10 patients with normal pressure hydrocephalus (mean age, 74 [SD, 6] years, with proved normal pressure hydrocephalus according to current scientific criteria); 2) eighteen age-matched healthy controls (mean age, 71 [SD, 5] years); and 3) fourteen young healthy controls (mean age, 21 [SD, 2] years, for investigation of age-related effects). Axial phase-contrast MR imaging was performed, and the maximal systolic CSF and total arterial blood flow rates were measured at the level of the upper second cervical vertebra and compared among all study groups (2-sample unpaired t test).

RESULTS

The maximal systolic CSF flow rate was significantly decreased in patients with normal pressure hydrocephalus compared with age-matched and young healthy controls (53 [SD,  40] mL/m; 329 [SD,  175] mL/m; 472 [SD, 194] mL/m; each P < .01), whereas there were no significant differences with regard to maximal systolic arterial blood flow (1160 [SD, 404] mL/m; 1470 [SD,  381] mL/m; 1400 [SD, 254] mL/m; each P > .05).

CONCLUSIONS

The reduced maximal systolic craniospinal CSF flow rate in patients with normal pressure hydrocephalus may be reflective of a reduced compliance of the spinal CSF spaces and an ineffective spinal CSF buffer function. Systolic craniospinal CSF flow rates are an easily obtainable MR imaging-based measure that may support the diagnosis of normal pressure hydrocephalus.

Management of cavernous sinus meningiomas: Consensus statement on behalf of the EANS skull base section

Introduction

The evolution of cavernous sinus meningiomas (CSMs) might be unpredictable and the efficacy of their treatments is challenging due to their indolent evolution, variations and fluctuations of symptoms, heterogeneity of classifications and lack of randomized controlled trials. Here, a dedicated task force provides a consensus statement on the overall management of CSMs.

Research question

To determine the best overall management of CSMs, depending on their clinical presentation, size, and evolution as well as patient characteristics.

Material and methods

Using the PRISMA 2020 guidelines, we included literature from January 2000 to December 2020. A total of 400 abstracts and 77 titles were kept for full-paper screening.

Results

The task force formulated 8 recommendations (Level C evidence). CSMs should be managed by a highly specialized multidisciplinary team. The initial evaluation of patients includes clinical, ophthalmological, endocrinological and radiological assessment. Treatment of CSM should involve experienced skull-base neurosurgeons or neuro-radiosurgeons, radiation oncologists, radiologists, ophthalmologists, and endocrinologists.

Discussion and conclusion

Radiosurgery is preferred as first-line treatment in small, enclosed, pauci-symptomatic lesions/in elderly patients, while large CSMs not amenable to resection or WHO grade II-III are candidates for radiotherapy. Microsurgery is an option in aggressive/rapidly progressing lesions in young patients presenting with oculomotor/visual/endocrinological impairment. Whenever surgery is offered, open cranial approaches are the current standard. There is limited experience reported about endoscopic endonasal approach for CSMs and the main indication is decompression of the cavernous sinus to improve symptoms. Whenever surgery is indicated, the current trend is to offer decompression followed by radiosurgery.

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A thorough evaluation of cavernous sinus meningiomas by a multidisciplinary team is mandatory.

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Microsurgery should be considered for aggressive lesions in young patients.

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Extended endoscopic approaches can be effective when combined with radiotherapy.

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Stereotaxic radiotherapy and stereotaxic radiosurgery offer excellent tumour control in small/asymptomatic lesions .

Long-term outcome of Simpson IV meningioma resection: Would it improve with adjuvant SRS?

OBJECTIVE

Subtotal meningioma resection (STR) is often performed to minimize surgical morbidity. Nevertheless, only a few studies have reported on patient outcome after STR. We studied the long-term outcome of SIV (Simpson grade IV) resection and identified predictive factors of overall survival (OS), progression-free survival (PFS) and time to progression (TTP).

METHODS

A retrospective analysis was performed on 68 patients who underwent SIV resection of meningioma (grade I) from 2004 to 2010. Data were collected from clinical, surgical and pathology records and radiological imaging. Long-term outcomes were evaluated at least 10 years after surgery.

RESULTS

Permanent morbidity was 11.8%, 30-day mortality 2.9% and progression rate 50.0% for a median follow-up duration of 126.6 months. Median TTP was 86.2 months. Adjuvant SRS was the only significant factor associated with longer PFS (p = 0.0052) and TTP (p = 0.0079). Higher age (p = 0.0022), KPS (p = 0.0182), postoperative ECOG score (p = 0.0182) were reliable predictors of shortened OS and aSRS (p = 0.0445) was reliable predictor of longer OS.

CONCLUSION

STR in intracranial meningioma is still viable and often the only treatment option available in high-risk patients or high-risk tumors. Although surgical morbidity and mortality are high, the OS rate was 85.3% at 5 years and 79.4% at 10 years. Because of the considerable progression rate and rather a long term OS the adjuvant SRS should be considered following SIV resection.

Predictors of visual functional outcome following treatment for cavernous sinus meningioma

OBJECTIVE

Cavernous sinus meningioma (CSM) can affect visual function and require expeditious treatment to prevent permanent visual loss. Authors of this retrospective study sought to determine the factors associated with visual functional outcomes in CSM patients treated with surgery, stereotactic radiosurgery (SRS), or stereotactic radiation therapy (SRT), alone or in combination.

METHODS

Consecutive patients with CSM who had presented at an academic tertiary care hospital from 2000 to 2018 were identified through retrospective chart review. Visual function-visual eye deficit (VED), optic disc (OD) appearance, intraocular pressure (IOP), and extraocular movement (EOM)-was assessed before and after treatment for CSM. VED with visual acuity (VA) ≤ 20/200 and visual field defect ≥ -11 dB, pale OD appearance in the ipsilateral or contralateral eye, increased ipsilateral IOP, and/or EOM restriction were defined as a poor visual functional outcome. Multivariable logistic regression was used to evaluate the associations between pretreatment visual functional assessment and posttreatment visual outcomes.

RESULTS

The study cohort included 44 patients (73% female; median age 55 years), with a median clinical follow-up of 14 months. Ipsilateral VED improved, remained stable, or worsened, respectively, in 0%, 33.4%, and 66.6% of the patients after subtotal resection (STR) alone; in 52.6%, 31.6%, and 15.8% after STR plus radiation treatment; in 28.5%, 43.0%, and 28.5% after gross-total resection (GTR) alone; and in 56.3%, 43.7%, and 0% after radiation treatment (SRS or SRT) alone. Contralateral VED remained intact in all the patients after STR alone and those with radiation treatment (SRS or SRT) alone; however, it improved, remained stable, or worsened in 10.5%, 84.2%, and 5.3% after STR plus radiation treatment and in 43.0%, 28.5%, and 28.5% after GTR alone. EOM remained intact, fully recovered, remained stable, and worsened, respectively, in 0%, 50%, 50%, and 0% of the patients after STR alone; in 36.8%, 47.4%, 15.8%, and 0% of the patients after STR with radiation treatment; in 57.1%, 0%, 28.6%, and 14.3% of the patients after GTR alone; and in 56.2%, 37.5%, 6.3%, and 0% of the patients after radiation treatment (SRS or SRT) alone. In multivariable analyses adjusted for age, tumor volume, and treatment modality, initial ipsilateral poor VED (OR 10.1, 95% CI 1.05-97.2, p = 0.04) and initial ipsilateral pale OD appearance (OR 21.1, 95% CI 1.6-270.5, p = 0.02) were associated with poor ipsilateral VED posttreatment. Similarly, an initial pale OD appearance (OR 15.7, 95% CI 1.3-199.0, p = 0.03), initial poor VED (OR 21.7, 95% CI 1.2-398.6, p = 0.03), and a higher IOP in the ipsilateral eye (OR 55.3, 95% CI 1.7-173.9, p = 0.02) were associated with an ipsilateral pale OD appearance posttreatment. Furthermore, a higher initial ipsilateral IOP (OR 35.9, 95% CI 3.3-400.5, p = 0.004) was indicative of a higher IOP in the ipsilateral eye posttreatment. Finally, initial restricted EOM was indicative of restricted EOM posttreatment (OR 20.6, 95% CI 18.7-77.0, p = 0.02).

CONCLUSIONS

Pretreatment visual functional assessment predicts visual outcomes in patients with CSM and can be used to identify patients at greater risk for vision loss.

Predictors of Survival in Subtotally Resected WHO Grade I Skull Base Meningiomas

BACKGROUND

Although gross total resection (GTR) is the goal in meningioma surgery, this can sometimes be difficult to achieve in skull base meningiomas. We analyzed clinical outcomes and predictors of survival for subtotally resected benign meningiomas.

METHODS

A total of 212 consecutive patients who underwent subtotal resection (STR) for benign skull base meningioma between 1990-2010 were investigated.

RESULTS

Median age was 57.7 [IQR 18.8] years, median preoperative Karnofsky performance status (KPS) was 80.0 [IQR 20.0], 75 patients (35.4%) had posterior fossa meningioma. After a median follow-up of 6.2 [IQR 7.9] years, retreatment (either radiotherapy or repeated surgery) rate was 16% at 1-year, 27% at 3-years, 34% at 5-years, and 38% at 10-years. Ten patients (4.7%) died perioperatively, 9 (3.5%) had postoperative hematomas, and 2 (0.8%) had postoperative infections. Neurological outcome at final visit was improved/stable in 122 patients (70%). Multivariable analysis identified advanced age and preoperative KPS < 70 as negative predictors for overall survival (OS). Patients who underwent retreatment had no significant reduction of OS.

CONCLUSIONS

Advanced age and preoperative KPS were independent predictors of OS. Retreatments did not prolong nor shorten the OS. Clinical outcomes in STR skull base meningiomas were generally worse compared to cohorts with high rates of GTR.

Predictors of recurrence and high growth rate of residual meningiomas after subtotal resection

OBJECTIVE

The extent of resection has been shown to improve outcomes in patients with meningiomas. However, resection can be complicated by constraining local anatomy, leading to subtotal resections. An understanding of the natural history of residual tumors is necessary to better guide postsurgical management and minimize recurrence. This study seeks to identify predictors of recurrence and high growth rate following subtotal resection of intracranial meningiomas.

METHODS

Adult patients who underwent primary surgical resection of a WHO grade I meningioma at a tertiary care institution from 2007-2017 were retrospectively reviewed. Volumetric tumor measurements were made on patients with subtotal resections. Stepwise multivariate proportional hazards regression analyses were performed to identify factors associated with time to recurrence, as well as stepwise multivariate regression analyses to assess for factors associated with high postoperative growth rate.

RESULTS

Of the 141 patients (18%) who underwent radiographic subtotal resection of an intracranial meningioma during the reviewed period, 74 (52%) suffered a recurrence, in which the median (interquartile range, IQR) time to recurrence was 14 (IQR 6-34) months. Among those tumors subtotally resected, the median pre- and postoperative tumor volumes were 17.19 cm3 (IQR 7.47-38.43 cm3) and 2.31 cm3 (IQR 0.98-5.16 cm3), which corresponded to a percentage resection of 82% (IQR 68%-93%). Postoperatively, the median growth rate was 0.09 cm3/year (IQR 0-1.39 cm3/year). Factors associated with recurrence in multivariate analysis included preoperative tumor volume (hazard ratio [HR] 1.008,95% confidence interval [CI] 1.002-1.013, p = 0.008), falcine location (HR 2.215, 95% CI 1.179-4.161, p = 0.021), tentorial location (HR 2.410, 95% CI 1.203-4.829, p = 0.024), and African American race (HR 1.811, 95% CI 1.042-3.146, p = 0.044). Residual volume (RV) was associated with high absolute annual growth rate (odds ratio [OR] 1.175, 95% CI 1.078-1.280, p < 0.0001), with the maximum RV benefit at < 5 cm3 (OR 4.056, 95% CI 1.675-9.822, p = 0.002).

CONCLUSIONS

By identifying predictors of recurrence and growth rate, this study helps identify potential patients with a high chance of recurrence following subtotal resection, which are those with large preoperative tumor volume, falcine location, tentorial location, and African American race. Higher RVs were associated with tumors with higher postoperative growth rates. Recurrences typically occurred 14 months after surgery.

Cranial Nerve Outcomes After Surgery for Frontal Skull Base Meningiomas: The Eternal Quest of the Maximum-Safe Resection with the Lowest Morbidity

OBJECTIVE

Maximal aggressive meningioma resection has been suggested to provide the best tumor control rates. However, radical surgery of meningiomas located at the frontal skull base can be accompanied by impairment of adjacent cranial nerve function that negatively affects patients' quality of life. We, therefore, analyzed our institutional database for cases of new cranial nerve deficits and postoperative cerebrospinal fluid (CSF) leakage stratified by the extent of tumor resection.

METHODS

From February 2009 to April 2017, 195 patients underwent resection of frontal skull base meningioma at our institution. Postoperative new deficits of cranial nerve function and CSF leakage were stratified by the resection into Simpson grade I resection with excision of the dural tail as an aggressive surgical approach and Simpson grade II-V resection.

RESULTS

Simpson grade I resection was associated with a significantly greater percentage of new cranial nerve deficits immediately after surgery (30%) compared with Simpson grade II (13%; P = 0.007) and Simpson grade II-V (17%; P = 0.035). The differences were greater at the 12-month follow-up point (29% Simpson grade I, 6% Simpson grade II [P < 0.001]; 10% Simpson grade II-V [P = 0.001]). Postoperative CSF leakage occurred in 10.1% of Simpson grade I versus 2.3% of Simpson grade II resections (P = 0.048). The retreatment rates did not differ between these 2 groups (2.5% vs. 3.4%; P = 1.000).

CONCLUSIONS

We found high levels of new cranial nerve morbidity and CSF leakage after radical removal of frontal skull base meningiomas that included the adjacent dura. Thus, less aggressive surgery for frontobasal meningioma should be preferred.

Three-dimensional multimodality fusion imaging as an educational and planning tool for deep-seated meningiomas

INTRODUCTION

The utility of surgical simulation with three-dimensional multimodality fusion imaging (3D-MFI) has been demonstrated. However, its potential in deep-seated brain lesions remains unknown. The aim of this study was to investigate the impact of 3D-MFI in deep-seated meningioma operations.

MATERIAL AND METHODS

Fourteen patients with deeply located meningiomas were included in this study. We constructed 3D-MFIs by fusing high-resolution magnetic resonance (MR) and computed tomography (CT) images with a rotational digital subtraction angiogram (DSA) in all patients. The surgical procedure was simulated by 3D-MFI prior to operation. To assess the impact on neurosurgical education, the objective values of surgical simulation by 3D-MFIs/virtual reality (VR) video were evaluated. To validate the quality of 3D-MFIs, intraoperative findings were compared. The identification rate (IR) and positive predictive value (PPV) for the tumor feeding arteries and involved perforating arteries and veins were also assessed for quality assessment of 3D-MFI.

RESULTS

After surgical simulation by 3D-MFIs, near-total resection was achieved in 13 of 14 (92.9%) patients without neurological complications. 3D-MFIs significantly contributed to the understanding of surgical anatomy and optimal surgical view (p < .0001) and learning how to preserve critical vessels (p < .0001) and resect tumors safety and extensively (p < .0001) by neurosurgical residents/fellows. The IR of 3D-MFI for tumor-feeding arteries and perforating arteries and veins was 100% and 92.9%, respectively. The PPV of 3D-MFI for tumor-feeding arteries and perforating arteries and veins was 98.8% and 76.5%, respectively.

CONCLUSIONS

3D-MFI contributed to learn skull base meningioma surgery. Also, 3D-MFI provided high quality to identify critical anatomical structures within or adjacent to deep-seated meningiomas. Thus, 3D-MFI is promising educational and surgical planning tool for meningiomas in deep-seated regions.

Radiosurgery and stereotactic radiotherapy with cyberknife system for meningioma treatment

Objective The aim of this work was to evaluate the impact of stereotactic radiosurgery/fractionated stereotactic radiotherapy with the Cyberknife system on local disease control, clinical outcome and toxicity in patients with meningioma, according to the site and histological grade of lesion. From January 2013 to April 2017, 52 patients with intracranial meningiomas were treated with the Cyberknife system. Twenty-four patients had undergone previous surgery: 38% gross total resection, 10% subtotal resection; 27 patients underwent no surgery; 22 patients had a recurrence of meningioma. Methods Radiosurgery was used for lesions smaller than 2 cm, stereotactic radiotherapy for lesions larger than 2 cm, or smaller but close to a critical site such as the optical chiasm, optic pathway or brainstem. Results Local control and clinical outcomes were analysed. Median follow-up was 20 months: six patients died, one after re-surgery died from post-surgical sepsis, three from heart disease. Progression-free survival had a mean value of 38.3 months and overall survival of 41.6 months. We evaluated at 12 months 28 patients (100% local control); at 24 months 19 patients (89% local control); at 36 months nine patients (89% local control). At baseline, 44/52 patients (85%) were symptomatic: 19 visual disorders, 17 motor disorders, six hearing disorders, 10 headache and six epilepsy. Visual symptoms remained unchanged in 52%, improved in 32%, resolved in 16%. Headache was improved in 40%, resolved in 10%, unchanged in 50%. Epilepsy was resolved in 17%, unchanged in 33%, worsened in 33%. Conclusions Stereotactic radiosurgery/fractionated stereotactic radiotherapy with Cyberknife provides a good local disease control, improving visual, hearing and motor symptoms.

Vascular risk factors in INPH: A prospective case-control study (the INPH-CRasH study)

OBJECTIVE

To assess the complete vascular risk factor (VRF) profile of idiopathic normal pressure hydrocephalus (INPH) using a large sample of representative patients with INPH and population-based controls to determine the extent to which vascular disease influences INPH pathophysiology.

METHODS

All patients with INPH who underwent shunting in Sweden in 2008-2010 were compared to age- and sex-matched population-based controls. Inclusion criteria were age 60-85 years and no dementia. The 10 most important VRFs and cerebrovascular and peripheral vascular disease were prospectively assessed using blood samples, clinical examinations, and standardized questionnaires. Assessed VRFs were hypertension, hyperlipidemia, diabetes, obesity, psychosocial factors, smoking habits, diet, alcohol intake, cardiac disease, and physical activity.

RESULTS

In total, 176 patients with INPH and 368 controls participated. Multivariable logistic regression analysis indicated that hyperlipidemia (odds ratio [OR] 2.380; 95% confidence interval [CI] 1.434-3.950), diabetes (OR 2.169; 95% CI 1.195-3.938), obesity (OR 5.428; 95% CI 2.502-11.772), and psychosocial factors (OR 5.343; 95% CI 3.219-8.868) were independently associated with INPH. Hypertension, physical inactivity, and cerebrovascular and peripheral vascular disease were also overrepresented in INPH. Moderate alcohol intake and physical activity were overrepresented among the controls. The population-attributable risk percentage was 24%.

CONCLUSIONS

Our findings confirm that patients with INPH have more VRFs and lack the protective factors present in the general population. Almost 25% of cases of INPH may be explained by VRFs. This suggests that INPH may be a subtype of vascular dementia. Targeted interventions against modifiable VRFs are likely to have beneficial effects on INPH.

Surgical management of medium and large petroclival meningiomas: a single institution's experience of 199 cases with long-term follow-up

BACKGROUND

Petroclival meningiomas (PCMs) were once regarded as 'inoperable' due to their complex anatomy and limited surgical exposure. This study aimed to evaluate the long-term outcomes of surgically treated PCMs larger than 2 cm.

METHODS

A series of 199 consecutive patients (137 females, 68.8 %) with PCMs larger than 2 cm from between 1993 and 2003 were included. The clinical charts, radiographs, and follow-ups were evaluated.

RESULTS

Gross total resection (GTR) was achieved in 111 (55.8 %) patients, subtotal resection (STR) in 65, and partial resection (PR) in 23. Cranial nerve dysfunctions were the most common complications and occurred in 133 (66.8 %) cases. The surgical mortality was 2.0 %. The Karnofsky Performance Scale (KPS) scores significantly decreased 1 month after the operations (preoperative KPS = 76.8 and postoperative KPS = 64.8; p = 0.011, Paired-samples t test). Long-term follow-ups were obtained in 142 patients, the follow-up duration was 171.6 months, and the most recent KPS was 83.2. Permanent morbidities remained in 24 patients (18.9 %). Multivariate analysis revealed that brainstem edema and tumors larger than 4 cm in diameter were independent risk factors in terms of outcomes (KPS < 80). The recurrence/progression rates were 14.5, 31.8, and 53.3 % for the GTR, STR, and PR cases, respectively (p = 0.002, Pearson χ (2) test). Gamma Knife radiosurgery for the remnants exhibited good tumor control.

CONCLUSIONS

Favorable outcomes and low mortality were achieved with the microsurgical management of medium and large PCMs; however, the rates of cranial nerves dysfunction remained high. Radically aggressive resection might not be judicious in terms of postoperative morbidity. The preoperative evaluations and intraoperative findings were informative regarding the outcomes. The low follow-up rate likely compromised our findings, and additional consecutive studies were required.

Case-Based Review: meningioma

Meningioma is by far the most common primary intracranial tumor in adults. Treatment of meningioma is complex due to a tremendous amount of variability in tumor behavior. Many patients are incidentally found to have tumors that will remain asymptomatic throughout their lives. It is important to identify these patients so that they can be spared from potentially morbid interventions. On the other end of the spectrum, high-grade meningiomas can behave very aggressively. When treatment is necessary, surgical resection is the cornerstone of meningioma therapy. Studies spanning decades have demonstrated that extent of resection correlates with prognosis. Radiation therapy, either in the form of external beam radiation therapy or stereotactic radiosurgery, represents another important therapeutic tool that can be used in place of or as a supplement to surgery. There are no chemotherapeutic agents of proven efficacy against meningioma, and chemotherapy treatment is generally reserved for patients who have exhausted surgical and radiotherapy options. Ongoing and future studies will help to answer unresolved questions such as the optimum use of radiation in resected WHO grade II meningiomas and the efficacy of additional chemotherapy agents.

Fractionated radiotherapy and radiosurgery of intracranial meningiomas

This review focuses on the role of radiosurgery and fractionated radiotherapy in the management of intracranial meningiomas, which are the most common benign intracranial tumors. Whenever feasible, surgery remains a cornerstone of treatment in effective health care treatment where modern radiotherapy plays an important role. Irradiation can be proposed as first-line treatment, as adjuvant treatment, or as a second-line treatment after recurrence. Stereotactic radiosurgery consists of delivering, a high-dose of radiation with high precision, to the tumor in a single-fraction with a minimal exposure of surrounding healthy tissue. Stereotactic radiosurgery, especially with the gamma knife technique, has reached a high level of success for the treatment of intracranial meningiomas with excellent local control and low morbidity. However, stereotactic radiosurgery is limited by tumor size,<3-4cm, and location, i.e. reasonable distance from the organs at risk. Fractionated radiation therapy is an interesting alternative (5 to 6weeks treatment time) for large inoperable tumors. The results of fractionated radiation therapy seem encouraging as regards both local control and morbidity although long-term prospective studies are still needed.

Surgical Experience of Infratentorial Meningiomas : Clinical Series at a Single Institution during the 20-Year Period

Objective

Based on surgical outcomes of patients with infratentorial meningiomas surgically treated at our institution, we analyzed the predictors for surgical resection, recurrence, complication, and survival.

Methods

Of surgically treated 782 patients with intracranial meningioma, 158 (20.2%) consecutive cases of infratentorial location operated on between April 1993 and May 2013 at out institute were reviewed retrospectively. The patients had a median age of 57.1 years (range, 16--77 years), a female predominance of 79.7%, and a mean follow-up duration of 48.4 months (range, 0.8--242.2 months).

Results

Gross total resection (Simpson's grade I & II) was achieved in 81.6% (129/158) of patients. Non-skull base location was an independent factor for complete resection. The recurrence rate was 13.3% (21/158) and the 5-, 10-, and 15-year recurrence rates were 8.2%, 12.0%, and 13.3%, respectively. Benign pathology, postoperative KPS over than 90, low peritumoral edema, and complete resection were significantly associated with longer recurrence-free survival rate. The 5-, 10-, and 15-year survival rates were 96.2%, 94.9%, and 94.9%, respectively. Benign pathology, postoperative KPS over than 90 and complete resection were significantly associated with a longer survival rate. The permanent complication rate was 13% (21/158). Skull base location and postoperative KPS less than 90 were independent factors for the occurrence of permanent complication.

Conclusion

Our experience shows that infratentorial meningiomas represent a continuing challenge for contemporary neurosurgeons. Various factors are related with resection degree, complications, recurrence and survival.

Endoscopic endonasal surgery for suprasellar meningiomas: experience with 75 patients

OBJECT

Following the introduction of the neurosurgical microscope, the outcomes in suprasellar meningioma surgery were dramatically improved. More recently, the neurosurgical endoscope has been introduced as a visualization option during removal of skull base tumors, both transcranially and endonasally. The authors retrospectively reviewed the effectiveness of endoscopic endonasal surgery (EES) in the management of suprasellar meningiomas.

METHODS

Between 2002 and 2011, 75 patients (81.3% female) with suprasellar meningiomas underwent EES at the University of Pittsburgh Medical Center. The authors present the results of EES and analyze the resection rates, visual outcome, and complications.

RESULTS

Seventy-one patients presented with primary tumors, whereas 4 were previously treated elsewhere. Their mean age was 57.3 years (range 36-88 years), and most patients presented with visual loss (81.3%). Tumors occupied the tuberculum sellae (86.7%) and planum sphenoidale (50.7%), with extension into the optic canals in 26.7% (unilateral in 21.3% and bilateral in 5.3%) and the pituitary fossa (9.3%). Gross-total tumor resection (Simpson Grade I) was achieved in 76% of the cases in the whole cohort and in 81.4% of the patients in whom it was the goal of surgery. Tumor location and extension into the optic canals was not a limitation for total resection. Tumor size, configuration, and vascular encasement were significant factors that influenced the degree of resection (p < 0.0001). Vision was improved or normalized in 85.7% of the cases. Visual deterioration following EES occurred in 2 patients (3.6%). Complications included postoperative CSF leaks (25.3% overall, 16.1% in recent years) resulting in meningitis in 4 cases. One patient had an intraoperative injury of the artery of Heubner resulting in associated neurological deficit. Another elderly patient died within 1 month after EES due to cerebral vasospasm and multisystem impairment. No patient developed postoperative cerebral contusions, hemorrhage, or seizures. During a mean follow-up period of 29 months (range 1-98 months), 4 patients have shown recurrence, but only 1 required repeat EES.

CONCLUSIONS

With the goal of gross-total tumor resection and visual improvement, EES can achieve very good results, (comparable to microscopic approaches) for the treatment of suprasellar meningiomas. Avoidance of brain and optic nerve retraction, preservation of the vascularization of the optic apparatus, and wide decompression of the optic canals are the main advantages of EES for the treatment of suprasellar meningiomas, while CSF leaks remain a disadvantage.

True petroclival meningiomas: results of surgical management

OBJECT

The relentless natural progression of petroclival meningiomas mandates their treatment. The management of these tumors, however, is challenging. Among the issues debated are goals of treatment, outcomes, and quality of life, appropriate extent of surgical removal, the role of skull base approaches, and the efficacy of combined decompressive surgery and radiosurgery. The authors report on the outcome in a series of patients treated with the goal of total removal.

METHODS

The authors conducted a retrospective analysis of 64 cases of petroclival meningiomas operated on by the senior author (O.A.) from 1988 to 2012, strictly defined as those originating medial to the fifth cranial nerve on the upper two-thirds of the clivus. The patients' average age was 49 years; the average tumor size (maximum diameter) was 35.48 ± 10.09 mm (with 59 tumors > 20 mm), and cavernous sinus extension was present in 39 patients. The mean duration of follow-up was 71.57 months (range 4-276 months).

RESULTS

In 42 patients, the operative reports allowed the grading of resection. Grade I resection (tumor, dura, and bone) was achieved in 17 patients (40.4%); there was no recurrence in this group (p = 0.0045). Grade II (tumor, dura) was achieved in 15 patients (36%). There was a statistically significant difference in the rate of recurrence with respect to resection grade (Grades I and II vs other grades, p = 0.0052). In all patients, tumor removal was classified based on postoperative contrast-enhanced MRI, and gross-total resection (GTR) was considered to be achieved if there was no enhancement present; on this basis, GTR was achieved in 41 (64%) of 64 patients, with a significantly lower recurrence rate in these patients than in the group with residual enhancement (p = 0.00348). One patient died from pulmonary embolism after discharge. The mean Karnofsky Performance Status (KPS) score was 85.31 preoperatively (median 90) and improved on follow-up to 88, with 30 patients (47%) having an improved KPS score on follow-up. Three patients suffered a permanent deficit that significantly affected their KPS. Cerebrospinal fluid leak occurred in 8 patients (12.5%), with 2 of them requiring exploration. Eighty-nine percent of the patients had cranial nerve deficits on presentation; of the 54 patients with more than 2 months of follow-up, 21 (32.8%) had persisting cranial nerve deficits. The overall odds of permanent cranial nerve deficit of treated petroclival meningioma was 6.2%. There was no difference with respect to immediate postoperative cranial nerve deficit in patients who had GTR compared with those who had subtotal resection.

CONCLUSIONS

Total removal (Grade I or II resection) of petroclival meningiomas is achievable in 76.4% of cases and is facilitated by the use of skull base approaches, with good outcome and functional status. In cases in which circumstances prevent total removal, residual tumors can be followed until progression is evident, at which point further intervention can be planned.

Controversies in radiotherapy for meningioma

Meningiomas are the most common primary intracranial tumour. Although external beam radiotherapy and radiosurgery are well-established treatments, affording local control rates of 85-95% at 10 years, the evidence base is mainly limited to single institution case series. This has resulted in inconsistent practices. It is generally agreed that radiotherapy is an established primary therapy in patients requiring treatment for surgically inaccessible disease and postoperatively for grade 3 tumours. Controversy exists surrounding whether radiotherapy should be upfront or reserved for progression for incompletely excised and grade 2 tumours. External beam radiotherapy and radiosurgery have not been directly compared, but seem to offer comparable rates of control for benign disease. Target volume definition remains contentious, including the inclusion of hyperostotic bone, dural tail and surrounding brain, but pathological studies are shedding some light. Most agree that doses around 50-54 Gy are appropriate for benign meningiomas and ongoing European Organization for Research and Treatment of Cancer and Radiation Therapy Oncology Group studies are evaluating dose escalation for higher risk disease. Here we address the 'who, when and how' of radiotherapy for meningioma.

Which drug or drug delivery system can change clinical practice for brain tumor therapy?

The prognosis and treatment outcome for primary brain tumors have remained unchanged despite advances in anticancer drug discovery and development. In clinical trials, the majority of promising experimental agents for brain tumors have had limited impact on survival or time to recurrence. These disappointing results are partially explained by the inadequacy of effective drug delivery to the CNS. The impediments posed by the various specialized physiological barriers and active efflux mechanisms lead to drug failure because of inability to reach the desired target at a sufficient concentration. This perspective reviews the leading strategies that aim to improve drug delivery to brain tumors and their likelihood to change clinical practice. The English literature was searched for defined search items. Strategies that use systemic delivery and those that use local delivery are critically reviewed. In addition, challenges posed for drug delivery by combined treatment with anti-angiogenic therapy are outlined. To impact clinical practice and to achieve more than just a limited local control, new drugs and delivery systems must adhere to basic clinical expectations. These include, in addition to an antitumor effect, a verified favorable adverse effects profile, easy introduction into clinical practice, feasibility of repeated or continuous administration, and compatibility of the drug or delivery system with any tumor size and brain location.

Posterior fossa meningioma "our experience" in 64 cases

Background:

Posterior fossa meningiomas are 20% of all intracranial meningiomas. These are slow-growing tumors thus become large before presentation. Microsurgical resection is the treatment of choice for the majority of these lesions, but variable locations, large size at diagnosis, frequent encroachment of neural and vascular structures, and their potentially invasive behavior are some of the features of these tumors that make their resection challenging.

Materials and Methods:

We studied 64 cases of posterior fossa meningioma operated in last 6 years, and analysed the technical difficulties encountered during excision of these tumors. Postoperative complications and outcomes of these patients were also analysed.

Results:

Gross total excision was achieved in 72% cases. Partial excision or subtotal excision was more in petroclival, jugular foramen with extra cranial extension, tentorial with intrasinus extension and ventral foramen magnum. Postoperative complication in form of new or aggravation of existing neurological deficit was found in 33% cases and CSF leak in 12.5% cases. We encountered the recurrence of total 10 cases (16%) over mean follow-up of 4 years. Most of the recurrent cases were seen in petroclival and tentorial subgroups with partial or subtotal excision.

Conclusion:

Posterior fossa meningiomas are difficult to excise due to close relation to cranial nerves and vessels. Use of microscope, CUSA, intraoperative nerve monitor help in removal and preserving surrounding important anatomical structures. Although neurological deterioration is common postoperatively, recovery does occur completely after total removal thus increasing the recurrence free period and improving the outcome.

A radiopathological classification of dural tail sign of meningiomas

Object

The completeness of meningioma resection depends on the resection of dura mater invaded by the tumor. The pathological changes of the dura around the tumor can be interpreted by evaluating the dural tail sign (DTS) on MRI studies. The goal of this study was to clarify the pathological characteristics of the DTSs, propose a classification based on the histopathological and radiological correlation, and identify the invasive range of tumor cells in different types of DTS.

Methods

The authors retrospectively reviewed 179 patients with convexity meningiomas who underwent Simpson Grade I resection. All patients underwent an enhanced MRI examination preoperatively. The convexity meningiomas were dichotomized into various subtypes in accordance with the 2007 WHO classification of tumors of the CNS, and the DTS was identified based on the Goldsher criteria. The range of resection of the involved dura was 3 cm from the base of the tumor, which corresponded with the length of DTS on MRI studies. Histopathological examination of dura at 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 cm from the base of the tumor was conducted, and the findings were correlated with the preoperative MRI appearance of the DTS.

Results

A total of 154 (86%) of 179 convexity meningiomas were classified into WHO Grade I subtype, including transitional (44 [28.6%] of 154), meningothelial (36 [23.4%] of 154), fibrous (23 [14.9%] of 154), psammomatous (22 [14.3%] of 154), secretory (10 [6.5%] of 154), and angiomatous (19 [12.3%] of 154). The other 25 (14%) were non–Grade I (WHO) tumors, including atypical (12 [48%] of 25), anaplastic (5 [20%] of 25), and papillary (8 [32%] of 25). The DTS was classified into 5 types: smooth (16 [8.9%] of 179), nodular (36 [20.1%] of 179), mixed (57 [31.8%] of 179), symmetrical multipolar (15 [8.4%] of 179), and asymmetrical multipolar (55 [30.7%] of 179). There was a significant difference in distribution of DTS type between Grade I and non–Grade I tumors (p = 0.004), whereas the difference was not significant among Grade I tumors (0.841) or among non–Grade I tumors (p = 0.818). All smooth-type DTSs were encountered in Grade I tumors, and the mixed DTS (52 [33.8%] of 154) was the most common type in these tumors. Nodular-type DTS was more commonly seen in non–Grade I tumors (12 [48%] of 25). Tumor invasion was found in 88.3% (158 of 179) of convexity meningiomas, of which the range of invasion in 82.3% (130 of 158) was within 2 cm and that in 94.9% (150 of 158) was within 2.5 cm. The incidence of invasion and the range invaded by tumor cells varied in different types of DTS, and differences were statistically significant (p < 0.001).

Conclusions

Nodular-type DTS on MRI studies might be associated with non–Grade I tumors. The range of dural resection for convexity meningiomas should be 2.5 cm from the tumor base, and if this extent of resection is not feasible, the type of DTS should be considered. However, for skull base meningiomas, in which mostly Simpson Grade II resection is achieved, the use of this classification should be further validated. The classification of DTS enables the surgeon to predict preoperatively and then to achieve the optimal range of dural resection that might significantly reduce the recurrence rate of meningiomas.

Evolution and future of skull base surgery: the paradigm of skull base meningiomas

BACKGROUND

Skull base meningiomas represent the paradigm for the evolution of skull base surgery within the past 50 years into a distinct neurosurgical subspecialty.

METHODS

From 2005 to 2011, 117 patients with cranial base meningiomas underwent surgical resection. Extent of resection, histologic grade, complications, functional status, and recurrence-free and overall survival data are presented.

RESULTS

The summary rate of gross total resection was 53.0%. The surgical complication and mortality rates were 17.9% and 0.9%, respectively. Five-year recurrence-free survival was 88.0% for grade I meningiomas. A total of 90.3% of patients had a Karnofsky performance score ≥ 80 at last follow-up.

CONCLUSIONS

A large contemporary series of skull base meningiomas is presented. In addition, the evolution of surgical approaches to skull base meningiomas is reviewed, together with the current issues regarding radiation therapy, management of cavernous sinus tumor, oncologic management of atypical and malignant subtypes, molecular genetics, and future therapeutic options.

Surgery for petroclival meningiomas: a comprehensive review of outcomes in the skull base surgery era

Skull base surgery has evolved to a point that its focus is now shifting to outcome analysis. To do so for petroclival meningiomas is difficult. The rarity of the tumor, different treatment philosophies, and variations in reporting complicate the outcome analysis. With this limitation in mind, we analyzed the literature on this disease and report the combined outcomes in a unified fashion in hopes that it will serve as a starting point for further prospective analysis. Data was extracted from all available reports on MEDLINE/PubMed published in English. All studies were retrospective and uncontrolled. The majority of studies represent the experience of a single surgeon at a single institution. Of the 19 studies with detailed demographic and outcome data, no data met criteria for meta-analysis. A total of 1000 patients were reported. The mean age of the patients was 50 years. The male to female ratio is 1:3. GTR (gross total resection) was reported in 49% of patients. Thirty-four percent of patients experienced some neurological deficit in the early postoperative period (<3 months). The most common morbidities reported were cranial nerve deficits (34.4% [range: 20 to 79%]) with facial nerve injury accounting for 19%, followed by motor deficits (14%), infection rates (1.6%), CSF leaks (5%), hemorrhage (1.2%), and hydrocephalus (1%). Death within 1 year of surgery was reported for 1.4% of patients. Once considered untreatable, petroclival meningiomas can now be approached relatively safely. There, however, still remains an ∼34% morbidity with the most common being cranial nerve. Despite this, >75% of patients return to independence at 1 year, many of which will resume employment. The nature of this study limits the conclusions that can be drawn; however, it provides some generalizations that may help guide patient questions regarding treatment outcomes.

Combined Endoscopic Endonasal Surgery and Fractionated Stereotactic Radiosurgery (fSRS) for Complex Cranial Base Tumors—Early Clinical Outcomes

Endoscopic endonasal surgery (EES) has been shown to be a feasible approach to cranial base tumors while reducing post-operative morbidity. Using the endoscopic endonasal approach alone or in combination with open approaches may provide advantages over conventional approaches. However, the balance between maximal resection and minimal injury to neurovascular structures frequently precludes gross total resection (GTR). Consequently, adjuvant radiation therapy may be an important option to improve local control (LC) of residual disease. In this retrospective series, we report clinical outcomes, morbidity, and LC of 40 patients with cranial base tumors treated with EES +/- combined open approach followed by fSRS (CyberKnife, Accuray Inc.). 26 patients had benign disease, 7 had newly diagnosed malignant disease, and 7 had previously resected malignant disease. Surgical outcomes were evaluable in all patients. LC after fSRS was evaluable in 39 patients and defined as no evidence of regrowth by MRI, CT, & physical examination. GTR was achieved in 12/40. Median post-operative length of stay (LOS) was 3 days. In multivariable analysis controlling for anatomic location and malignant histology, post-operative complications (n = 10) were significantly associated with patients having combined open and EES (p < 0.01, OR = 16.9). SRS was delivered in 1–5 sessions to a median marginal dose of 24.9 Gy. Median follow-up was 24.7 months (range, 1.5 to 61 months). LC was achieved in 89.7% (35/39) of evaluable patients. LC was achieved in 11/12 patients who had GTR. Median progression-free survival was 19.7 months (21.0 months for benign tumors (n = 26), 5.8 months for previously resected malignant disease (n = 7), and 21.2 months for newly diagnosed malignant disease (n = 7). Of the 31 patients who had symptomatic disease at presentation, 18 (58%) reported complete symptom resolution, 9 partial, and 4 no improvement. One patient who received two prior courses of radiation therapy developed osteosclerosis (grade III). Other adverse events were erythema (grade I, n = 5), nausea (grade II, n = 2), conjunctivitis (grade II, n = 1). EES followed by fSRS is a safe and effective management strategy for selected cranial base tumors. EES combined with an open surgical approach may result in increased complications. However, initial follow-up offers encouraging results indicating shorter time to recovery, acceptable LC rates compared to conventional approaches, and similar median time to progression for benign and newly diagnosed malignant disease.

FACT-MNG: tumor site specific web-based outcome instrument for meningioma patients

To formulate Functional Assessment of Cancer Therapy-Meningioma (FACT-MNG), a web-based tumor site-specific outcome instrument for assessing intracranial meningioma patients following surgical resection or stereotactic radiosurgery. We surveyed the relevant literature available on intracranial meningioma surgery and subsequent outcomes (38 papers), making note of which, if any, QOL/outcome instruments were utilized. None of the surgveyed papers included QOL assessment specific to tumor site. We subsequently developed questions that were relevant to the signs and symptoms that characterize each of 11 intracranial meningioma sites, and incorporated them into a modified combination of the Functional Assessment of Cancer Therapy-Brain (FACT-BR) and SF36 outcome instruments, thereby creating a new tumor site-specific outcome instrument, FACT-MNG. With outcomes analysis of surgical and radiosurgical treatments becoming more important, measures of the adequacy and success of treatment are needed. FACT-MNG represents a first effort to formalize such an instrument for meningioma patients. Questions specific to tumor site will allow surgeons to better assess specific quality of life issues not addressed in the past by more general questionnaires.

Risk factors for the development of serious medical complications after resection of meningiomas. Clinical article

OBJECT

While the surgical and neurological risks of meningioma surgery have been reported, much less effort has been devoted to studying the rates of serious medical complications following such a procedure. The authors performed a review of 834 patients who underwent craniotomy for meningioma at their institution and analyzed the rate of major cardiac, pulmonary, renal, and hepatic complications.

METHODS

The authors identified all patients between 1993 and 2007 who underwent craniotomy for meningioma. Clinical information was reconstructed using patient medical records, medication records, radiological data, and pathological specimens from both the author institution and outside medical facilities. Stepwise multivariate logistic regression analysis was performed to test the association between the dependent variable (rate of medical complications) and all covariates with a p < 0.2 on univariate testing.

RESULTS

Fifty-seven patients (6.8%) experienced 61 serious medical complications following surgery for meningioma. Four patients died of medical complications. The most common complication was pneumonia, followed by renal dysfunction, arrhythmia, and deep venous thrombosis and/or pulmonary embolus. The development of a new or worsened neurological deficit (p < 0.00001), an age > 65 years (p < 0.03), hypertension (p < 0.02), and being on > 2 cardiac medications prior to surgery (p < 0.004) all demonstrated significantly increased rates of medical complications on univariate analysis. On multivariate analysis, only a new or worsened neurological deficit remained a significant risk factor for the occurrence of serious medical complications (p < 0.00001).

CONCLUSIONS

Overall, the authors found that the rate of clinically detected serious medical complications is relatively low in this population (6.8%), given the duration and complexity of the meningioma operations, and is strongly linked to the subsequent development of significant medical complications. This information may be useful to surgeons in discussing the morbidity of surgery during the informed consent process.

The relevance of Simpson Grade I and II resection in modern neurosurgical treatment of World Health Organization Grade I meningiomas

OBJECT

In 1957, Simpson published a seminal paper defining the risk factors for recurrence following surgical treatment of intracranial meningiomas. Given that Simpson's study was published more than 50 years ago, preceding image guidance technology and MR imaging, the authors reviewed their own experience with surgical treatment of Grade I meningiomas to determine if Simpson's grading scale is still relevant to modern neurosurgical practice.

METHODS

From this cohort, the authors evaluated all patients undergoing craniotomy for resection of a histologically proven WHO Grade I meningioma as their initial therapy. Clinical information was retrospectively reconstructed using patient medical records and radiological data. Recurrence analysis was performed using the Kaplan-Meier method.

RESULTS

The 5-year recurrence/progression-free survival for all patients receiving a Simpson Grade I, II, III, or IV resection was 95, 85, 88, and 81%, respectively (p = not significant, log-rank test). Kaplan-Meier analysis revealed no significant difference in recurrence-free survival between patients receiving a Simpson Grade I, II, III, or IV resection. Analysis limited to meningiomas arising from the skull base (excluding the cavernous sinus) similarly found no significant benefit to Simpson Grade I or II resection, and the survival curves were nearly superimposed.

CONCLUSIONS

In this study of a cohort of patients undergoing surgery for WHO Grade I meningiomas, the authors demonstrate that the benefit of more aggressive attempts to resect the tumor with dura and underlying bone was negligible compared with simply removing the entire tumor, or even leaving small amounts of tumor attached to critical structures. The authors believe that these data reflect an evolution in the nature of meningioma surgery over the past 2 decades, and bring into question the relevance of using Simpson's grading system as the sole predictor of recurrence.

The role of radical microsurgical resection in multimodal treatment for skull base meningioma

OBJECT

Because resection followed by timely stereotactic radiosurgery (SRS) is becoming a standard strategy for skull base meningiomas, the role of initial surgical tumor reduction in this combined treatment should be clarified.

METHODS

This study examined 161 patients with benign skull base meningiomas surgically treated at Osaka City University between January 1985 and December 2005. The mean follow-up period was 95.3 months. Patients were categorized into 3 groups based on the operative period and into 4 groups based on tumor location. Maximal resection was performed as first therapy throughout all periods. In the early period (1985-1994), in the absence of SRS, total excision of the tumor was intentionally performed for surgical cure of the disease. In the mid and late periods (1995-2000 and 2001-2005), small parts of the tumor invading critical neurovascular structures were left untouched to obtain good functional results. Residual tumors with high proliferation potential (Ki 67 index > 4%) or with progressive tendencies were treated with SRS. The extent of initial tumor resection, recurrence rate, Karnofsky Performance Scale score, and complication rate were investigated in each group.

RESULTS

The mean tumor equivalent diameter of residual tumors was 3.67 mm in the no-recurrence group and 11.7 mm in the recurrence group. The mean tumor resection rate (TRR) was 98.5% in the no-recurrence group and 90.1% in the recurrence group. A significant relationship was seen between postoperative tumor size, TRR, and recurrence rate (p < 0.001), but the recurrence rate showed no significant relationship with any other factors such as operative period (p = 0.48), tumor location (p = 0.76), or preoperative tumor size (p = 0.067). The mean TRR was maintained throughout all operative periods, but the complication rate was lowest and postoperative Karnofsky Performance Scale score was best in the late period (p < 0.001 each). Late-period results were as follows: mean TRR, 97.9%; mortality rate, 0%; and severe morbidity rate, 0%. Stereotactic radiosurgery procedures were added in 27 cases (16.8%) across all periods. Throughout all follow-up periods, 158 tumors were satisfactorily controlled by maximal possible excision alone or in combination with adequate SRS.

CONCLUSIONS

The combination of maximal possible resection and additional SRS improves functional outcomes in patients with skull base meningioma. A TRR greater than 97% in volume can be achieved with satisfactory functional preservation and will lead to excellent tumor control in combined treatment of skull base meningioma.

ABC Surgical Risk Scale for skull base meningioma: a new scoring system for predicting the extent of tumor removal and neurological outcome. Clinical article

OBJECT

Surgery for skull base meningiomas (SBMs) can lead to complications because these lesions are difficult to approach and can involve cranial nerves and arteries. The authors propose a scoring system to evaluate the relative risks and benefits of surgical treatment of SBMs.

METHODS

The authors used a 2-step process to construct their scale. First, they derived significant predictive variables from retrospective data on 132 SBM cases treated surgically (primary surgeries only) between May 2000 and December 2005. Next, they validated the predictive accuracy of their scoring system in 60 consecutive cases treated surgically between January 1995 and April 2000, including both primary and repeated surgeries. Finally, they investigated the effect of the surgery on the patients' preoperative symptoms for consecutive cases treated surgically between January 1995 and December 2005, including both primary surgeries and retreatments.

RESULTS

Five items that predicted surgical risk were identified: 1) tumor attachment size; 2) arterial involvement; 3) brainstem contact; 4) central cavity location; and 5) cranial nerve group involvement. The authors named their scoring system the ABC Surgical Risk Scale, after the initial letters of these items. Each factor was assigned a score of 0-2 points, and an additional point was added for previous surgical treatment or for radiation, giving a possible total score of 12 points. On average, the scoring system allocated 2 points for gross-total resections, 6.1 points for near-total resections, and 9 points for subtotal resections, with significant differences between groups. For cases scoring >or= 8 points, the percentage of cases showing neurological deterioration postoperatively exceeded the percentage showing improvement.

CONCLUSIONS

The authors conclude that this scoring system can be used to predict the extent of tumor removal and that the scores reflect the surgical risk.

Endonasal versus supraorbital keyhole removal of craniopharyngiomas and tuberculum sellae meningiomas

OBJECTIVE

Endonasal and supraorbital "eyebrow" craniotomies are increasingly being used to remove craniopharyngiomas and tuberculum sellae meningiomas. Herein, we assess the relative advantages, disadvantages, and selection criteria of these 2 keyhole approaches.

METHODS

All consecutive patients who had endonasal or supraorbital removal of a craniopharyngioma or tuberculum sellae meningioma were analyzed.

RESULTS

Of 43 patients, 22 had a craniopharyngioma (18 endonasal, 4 supraorbital), and 21 had a meningioma (12 endonasal, 7 supraorbital, 2 both routes); 33% had prior surgery. Craniopharyngiomas were primarily retrochiasmal in location in 78% of endonasal cases versus 25% of supraorbital cases (P = 0.08). Meningiomas were larger when approached by the supraorbital route versus the endonasal route (33 +/- 10 versus 25 +/- 8 mm, respectively; P = 0.008). Endoscopy was used in 84% of endonasal approaches and in 31% of supraorbital approaches (P = 0.001). Of patients having first-time surgery for a craniopharyngioma (n = 14) or meningioma (n = 15), total/near total removal was achieved in 83% and 80% of patients by the endonasal route and in 50% and 80% of patients by the supraorbital route, respectively. Vision improved in 87% and 70% of patients who had surgery by an endonasal versus supraorbital route, respectively (P = 0.3). Visual deterioration occurred in 2 patients with meningiomas, 1 by endonasal (7%), and 1 by supraorbital (11%) removal. The endonasal approach was associated with a higher rate of postoperative cerebrospinal fluid leaks (16 versus 0%; P = 0.3), 4 of 5 of which occurred in patients with meningioma.

CONCLUSION

The endonasal route is preferred for removal of most retrochiasmal craniopharyngiomas, whereas the supraorbital route is recommended for meningiomas larger than 30 to 35 mm or with growth beyond the supraclinoid carotid arteries. For smaller midline tumors, either approach can be used, depending on surgeon experience and tumor anatomy. Compared with traditional craniotomies, the major limitation of both approaches is a narrow surgical corridor. The endonasal approach has the added challenges of restricted lateral suprasellar access, a greater need for endoscopy, and a more demanding cranial base repair.

Cyberknife radiosurgery for benign meningiomas: short-term results in 199 patients

OBJECTIVE

To present initial, short-term results obtained with an image-guided radiosurgery apparatus (CyberKnife; Accuray, Inc., Sunnyvale, CA) in a series of 199 benign intracranial meningiomas.

METHODS

Selection criteria included lesions unsuitable for surgery and/or remnants after partial surgical removal. All patients were either symptomatic and/or harboring growing tumors. Ninety-nine tumors involved the cavernous sinus; 28 were in the posterior fossa, petrous bone, or clivus; and 29 were in contact with anterior optic pathways. Twenty-two tumors involved the convexity, and 21 involved the falx or tentorium. One hundred fourteen patients had undergone some kind of surgical removal before radiosurgery. Tumor volumes varied from 0.1 to 64 mL (mean, 7.5 mL) and radiation doses ranged from 12 to 25 Gy (mean, 18.5 Gy). Treatment isodoses varied from 70 to 90%. In 150 patients with lesions larger than 8 mL and/or with tumors situated close to critical structures, the dose was delivered in 2 to 5 daily fractions.

RESULTS

The follow-up periods ranged from 1 to 59 months (mean, 30 months; median, 30 months). The tumor volume decreased in 36 patients, was unchanged in 148 patients, and increased in 7 patients. Three patients underwent repeated radiosurgery, and 4 underwent operations. One hundred fifty-four patients were clinically stable. In 30 patients, a significant improvement of clinical symptoms was obtained. In 7 patients, neurological deterioration was observed (new cranial deficits in 2, worsened diplopia in 2, visual field reduction in 2, and worsened headache in 2).

CONCLUSION

The introduction of the CyberKnife extended the indication to 63 patients (>30%) who could not have been treated by single-session radiosurgical techniques. The procedure proved to be safe. Clinical improvement seems to be more frequently observed with the CyberKnife than in our previous linear accelerator experience.

Combined proton and photon conformal radiotherapy for intracranial atypical and malignant meningioma

PURPOSE

To evaluate retrospectively the efficacy of conformal fractionated radiotherapy combining proton and photon beams after primary surgery for treatment of atypical and malignant meningiomas.

PATIENTS AND METHODS

Between September 1999 and October 2006, 24 patients (12 male, 12 female) with histopathologically proven meningioma (atypical 19, malignant 5) received postoperative combined radiotherapy with a 201-MeV proton beam at the Centre Protontherapie d'Orsay and a high-energy photon beam. Six patients underwent gross total resection and 18 a subtotal resection. Median gross tumor volume and clinical target volume were 44.7 cm(3) and 153.3 cm(3), respectively. Mean total irradiation dose was 65.01 CGE (cobalt gray equivalent), with a mean proton total dose of 34.05 CGE and a mean photon total dose 30.96 CGE.

RESULTS

The median (range) follow-up interval was 32.2 (1-72) months. The overall mean local relapse-free interval was 27.2 (10-50) months, 28.3 (10-50) months for atypical meningioma and 23 (13-33) months for malignant meningioma. Ten tumors recurred locally. One-, 2-, 3-, 4-, 5-, and 8- year local control rates for the entire group of patients were 82.9% +/- 7.8%, 82.9% +/- 7.8%, 61.3% +/- 11%, 61.3% +/- 11%, 46.7% +/- 12.3%, and 46.7% +/- 12.3%, respectively. One-, 2-, 3-, 4-, 5-, and 8- year overall survival rates were 100%, 95.5% +/- 4.4%, 80.4% +/- 8.8%, 65.3% +/- 10.6%, 53.2% +/- 11.6%, and 42.6% +/- 13%, respectively. Survival was significantly associated with total dose. There was no acute morbidity of radiotherapy. One patient developed radiation necrosis 16 months after treatment.

CONCLUSIONS

Postoperative combination of conformal radiotherapy with protons and photons for atypical and malignant meningiomas is a well-tolerated treatment producing long-term tumor stabilization.

Meningioma with dural venous sinus invasion and jugular vein extension

Meningiomas represent the most common benign intracranial neoplasm in adults, with a considerably lower incidence in children. The authors present the case of an intracranial meningioma with invasion of, and intraluminal extension into, the transverse and sigmoid sinuses, jugular bulb, and internal jugular vein, resulting in venous occlusion in a 14-year-old girl. Computed tomography scanning, MR imaging, and conventional angiography were performed preoperatively. The patient underwent a 2-stage resection: the supratentorial component was resected first, and the infratentorial and venous sinus and jugular vein components were subsequently removed using a combined skull base approach. Gross-total resection was achieved by opening the lateral dural sinus and removing the meningioma from within the transverse and sigmoid sinuses, the jugular bulb, and the internal jugular vein. The patient remained neurologically intact after the staged tumor resections. Postoperative imaging confirmed the gross-total resection. This case illustrates the unusual property of an intracranial meningioma to invade the intrasinusoidal space and extend into the jugular vein without adherence to the underlying venous endothelium of the jugular vein.

Idiopathic normal pressure hydrocephalus: increased supplementary motor activity accounts for improvement after CSF drainage

In patients with idiopathic normal pressure hydrocephalus (INPH), the changes in brain function that take place in conjunction with improved behavioural performance after CSF drainage is still unknown. In this study, we use functional MRI (fMRI) to investigate the changes in cortical activity that accompany improved motor and cognitive performance after long-term external lumbar drainage (ELD) of CSF in patients with INPH. Eighteen INPH patients were initially included together with age- and sex-matched controls. Data from 11 INPH patients were analysed both before and after ELD. The average drain volume for these 11 patients was 400 ml/3 days. Brain activation was investigated by fMRI before and after the procedure on a 1.5T Philips scanner using protocols taxing motor performance (finger tapping and reaction time) and cognitive functioning (memory and attention). Behavioural data were compared using non-parametric tests at a significance level of 0.05, whereas fMRI data were analysed by statistical parametric mapping including conjunction analysis of areas with enhanced activity after drainage in patients and areas activated in controls (P < 0.005, uncorrected). Improved regions were defined as areas in the INPH brain that increased in activity after ELD with the requirement that the same areas were activated in control subjects. Following ELD, right-hand finger tapping improved from 104 +/- 38 to 117 +/- 25 (mean +/- SD) (P = 0.02). Left-hand finger tapping showed a tendency to improve, the number of keystrokes increasing from 91 +/- 40 to 105 +/- 20 (P = 0.12). Right-hand reaction time improved from 1630 +/- 566 ms to 1409 +/- 442 ms, whereas left-hand reaction time improved from 1760 +/- 600 ms to 1467 +/- 420 ms (both P-values = 0.01). Significant improvements in motor performance were accompanied by bilateral increased activation in the supplementary motor area. No improvement was found in cognitive functioning. The results suggest that motor function recovery in INPH patients after CSF removal is related to enhanced activity in medial parts of frontal motor areas considered crucial for motor planning; a finding consistent with INPH being a syndrome related to a reversible suppression of frontal periventricular cortico-basal ganglia-thalamo-cortical pathways.

Meningioma

Meningiomas are mostly benign tumours originating from the arachnoid cap cells, represent 13-26% of all intracranial tumours. They are more common in older age and in females. Deletion in NF2 gene and exposure to ionizing radiation are established risk factors, while the role of sex hormones is yet not clarified. Five-year survival for typical meningiomas exceeds 80%, but is poorer (5-year survival <60%) in malignant and atypical meningiomas. Papillary and haemangiopericytic morphology, large tumour size, high mitotic index, absence of progesterone receptors, deletions and loss of heterozygosity are poor prognostic factors. Complete surgical excision is the standard treatment. Radiotherapy is currently used in the clinical practice in atypical, malignant or recurrent meningioma at a total dose of 45-60Gy. However, the role of adjuvant irradiation is still controversial and has to be compared in a randomised prospective setting with a policy of watchful waiting. Radiosurgery has gained more and more importance in the management of meningiomas, especially in meningiomas that cannot be completely resected as for many skull base meningiomas. Medical therapy for patients with recurrent, progressive and symptomatic disease after repeated surgery, radiosurgery and radiotherapy is investigational. Hormonal therapy with progesterone antagonists has shown modest results, while chemotherapy with hydroxyurea appears moderately active.

[Relation of surgical results and proposed skull base meningioma grading system: analysis of clinical series with 42 patients]

Anatomical localisation of skull base meningioma link, their growth and relations with neurovascular structures reduce possibility for radical operation, and offten request additional preoperative or postoperative radiotherapy. We compared personal results of extent surgical resection and skull base meningioma treating outcome with predispose factors scale for surgical radicality and postoperative outcome. We present 42 patients, who were operated in Institute of neurosurgery CCS during the period from 2004 to 2006.

RESULTS

Radical resection was possible in 29 cases, and in 13 cases reduction of tumor mass has been performed. Statistical significant predispose factor for radical resection were: absance of preoperative radiotherapy, intact functions of n.III, n.VI, tumor borders inside one skull base fossa and outside of magistral blood vessels. Karnofsky index at the end of following period statistical significant higher in patients with radical resection of skull base meningeioma. Preoperative radiological finding is singificant guide in planning of therapeutic protocol for skull base meningioma. Growth of tumor and relation with neurovascular structures restrict extent of resection and often request additional postoperative radiotherapy or reoperation.

Long-term follow-up of meningiomas of the cavernous sinus after surgical treatment alone

Object

The authors report on the long-term outcome in 100 consecutive patients with meningiomas arising from the cavernous sinus (CS) with compressive extension outside the CS. The treatment in all cases was surgery alone without adjuvant radiosurgery or radiotherapy. The aim of this study was to evaluate the percentage of patients in whom surgery alone was able to produce long-term tumor control.

Methods

All 100 patients harbored meningiomas with supra- and/or laterocavernous extension, and 27 had petro-clival extension. Surgery was performed via frontopterionotemporal craniotomy associated with orbital and/or zygomatic osteotomy in 97 patients. Proximal control of the internal carotid artery at the foramen lacerum was undertaken in 65 patients; the paraclinoid carotid segment was exposed extradurally at the space made by the anterior clinoidectomy in 81 patients. For the petroclival tumor extension, a second-stage surgery was performed via a presigmoid–retro-labyrinthine or retrosigmoid approach in 13 and 14 patients, respectively.

Results

The mortality rate was 5% and two patients had severe hemiplegic or aphasic sequelae. The creation or aggravation of disorders in vision, ocular motility, or trigeminal function occurred in 19, 29, and 24% of patients respectively, with a significantly higher rate of complications when resection was performed inside the CS (p < 0.05).

Gross-total removal of both the extra- and intracavernous portions was achieved in 12 patients (Group 1), removal of the extracavernous portions with only a partial resection of the intracavernous portion in 28 patients (Group 2), and removal only of the extracavernous portions was performed in 60 patients (Group 3). The follow-up period ranged from 3 to 20 years (mean 8.3 years). There was no tumor recurrence in Group 1. In the 83 surviving patients in Groups 2 and 3 combined, the tumor remnant did not regrow in 72 patients (86.7%); regrowth was noted in 11 (13.3%).

Conclusions

The results suggest that there is no significant oncological benefit in performing surgery within the CS. Because entering the CS entails a significantly higher risk of complications, radiosurgical treatment should be reserved for remnants with secondary growth and clinical manifestations.

Patterns of skull base meningioma progression after failed radiosurgery

Object

Stereotactic radiosurgery has been reported to be an effective alternative to surgical removal of small to medium benign meningiomas as well as an adjuvant treatment modality to reduce the risk of tumor progression after subtotal resection. Its efficacy has been proved by excellent short-term radiosurgically demonstrated control rates, which have been reported to approach or exceed 90% in many contemporary studies involving the use of either linear accelerator–based systems or the Gamma Knife. Little is known, however, regarding the growth patterns of meningiomas that fail to stabilize after radiosurgery.

Methods

The authors report 13 cases of benign skull base meningiomas (World Health Organization Grade I) that demonstrated progression after radiosurgical treatment as a primary or an adjuvant therapy. Several tumors demonstrated rapid growth immediately after radiosurgical treatment, whereas other lesions progressed in a very delayed manner in some patients (up to 14 years after treatment). Regardless of the interval after which it occurs, tumor growth can be quite aggressive once it has begun.

Conclusions

Skull base meningioma growth can be aggressive after failed radiosurgery in some patients, and treatment failure can occur at long intervals following treatment. Special attention must be devoted to such significant occurrences given the increasing number of patients undergoing stereotactic radiosurgery for benign tumors, and careful extended (> 10 years) follow up must be undertaken in all patients after radiosurgery.

Calcium Channel Antagonists Augment Hydroxyurea- And Ru486-Induced Inhibition Of Meningioma Growth In Vivo And In Vitro

OBJECTIVE

Although the chemotherapy drug hydroxyurea (HU) and the antiprogesterone mifepristone (RU486) have been used to treat meningiomas for which surgical and radiation therapies have failed, results have been disappointing. The addition of calcium channel antagonists (CCAs) to chemotherapeutic drugs enhances tumor growth inhibition in other tumor types, and the authors demonstrated that CCAs can block meningioma growth in vitro and in vivo. The purpose of this study was to test the effects of the addition of a CCA to HU or RU486 on meningioma growth.

METHODS

Primary and malignant (IOMM-Lee) meningioma cell lines were treated with HU, RU486, or either of these plus diltiazem or verapamil. Assays for cell growth, apoptosis, and fluorescent-activated cell sorting were performed on in vitro cultures. Similar cell lines were implanted into nude mice and were treated with HU or RU486, in combination with a CCA. Tumors were analyzed by light microscopy, MIB-1, and factor VIII immunohistochemical staining studies.

RESULTS

The addition of diltiazem or verapamil to HU or RU486 augmented meningioma growth inhibition by 20 to 60% in vitro. In vivo, tumors treated with combination drugs were smaller; and immunohistochemical analysis of the IOMM-Lee tumors showed a 10% decrease in the MIB-1 ratio (from 0.41 to 0.30) and an approximate 75% decrease in microvascular density.

CONCLUSION

The addition of diltiazem or verapamil to HU or RU486 augments meningioma growth inhibition in vitro by inducing apoptosis and G1 cell-cycle arrest. The combination of HU and diltiazem inhibited the growth of meningiomas in vivo by decreasing proliferation and microvascular density. These results suggest a possible role for these drugs as an additional adjuvant therapy for recurrent or unresectable meningiomas.

Meningioma

Total excision is an appropriate treatment option for patients with benign meningiomas that are resectable with minimal morbidity. It is particularly appropriate for patients with significant mass effect causing symptoms. Fractionated conformal radiotherapy is an appropriate primary treatment option for patients with benign meningiomas of all sizes and all sites. It is particularly appropriate and preferred for optic nerve sheath meningiomas, for which there are few alternatives. Planned subtotal resection is appropriate if decompression is expected to relieve acute symptoms. After subtotal resection, it is appropriate to offer single-fraction radiosurgery or multifraction radiotherapy, depending on the size, location, and extent of residual tumor, so as to achieve progression-free survival and cause-specific survival rates comparable to those of other approaches.

Levine-Sekhar grading system for prediction of the extent of resection of cranial base meningiomas revisited: study of 124 cases

INTRODUCTION

Skull base meningiomas comprise an intricate kingdom in neurological surgery. Due to their proximity to critical neurovascular structures, these tumours impose a cumbersome burden on the surgeon regarding surgical intervention and the clinical outcome. Preoperative prediction of the meningioma resectability will help the surgeon seek a rational result from surgery. This study tries to re-examine and promote the Levine-Sekhar (LS) grading system proposed to predict the resectability of basal meningiomas.

PATIENTS AND METHODS

A retrospective study was performed on 124 eligible patients (90 female and 34 male) suffering from cranial base meningioma that had been operated on between April 1996 and February 2003. The patients were classified according to LS and our modified grading systems. The modified grading system deploys six groups of variables: optic apparatus involvement, cavernous sinus neural involvement, facial-auditory involvement, caudal cranial nerve dysfunction, data derived from imaging studies (multiple fossa involvement and/or vessel encasement), and history of previous radiosurgery. Each criterion scores 1 if present and the total score is the sum of scores obtained from the aforementioned criteria.

RESULTS

Amongst 124 patients, 66 (52%) underwent gross total removal of the tumour. Regression and correlation analysis were performed for both LS (r(2) = 0.9683) and our modified grading systems (r(2) = 0.990) to evaluate the relationship of tumour grade versus the proportion of total resection. The correlations were significantly different (P < 0.01).

CONCLUSION

Although the LS grading system is reported to be a good predictor of the extent of tumour resection, we believe that application of the six aforementioned variables will enhance the accuracy of this system, while preserving simplicity and communicability.

Surgical management of petroclival meningiomas: defining resection goals based on risk of neurological morbidity and tumor recurrence rates in 137 patients

OBJECTIVE

Meningiomas arising from the petroclival region remain a challenging surgical problem. Because of the substantial risk of neurological morbidity, uniformly pursuing a gross total resection (GTR) to minimize tumor recurrence rates may not be justified. We sought to define optimal resection goals based on risk factors for postoperative neurological morbidity and tumor recurrence rates.

METHODS

This series represents our experience with 137 meningiomas arising from the petroclival region resected between June 1993 and October 2002. There were 38 male and 99 female patients with a mean age of 53 years.

RESULTS

GTR was achieved in 40% of patients, and near total resection (NTR) was achieved in 40% of patients. One operative death occurred. Twenty-six percent of patients experienced new postoperative cranial nerve deficits, paresis, or ataxia when assessed at a mean follow-up of 8.3 months. The risk of cranial nerve deficits increased with prior resection (P < 0.001), preoperative cranial nerve deficit (P = 0.005), tumor adherence to neurovascular structures (P = 0.046), and fibrous tumor consistency (P = 0.005). The risk of paresis or ataxia increased with prior resection (P = 0.001) and tumor adherence (P = 0.045). Selective NTR rather than GTR in patients with adherent or fibrous tumors significantly reduced the rate of neurological deficits. Radiographic recurrence or progression occurred in 17.6% of patients at a mean follow-up of 29.8 months. Tumor recurrence rates after GTR and NTR did not differ significantly (P = 0.111).

CONCLUSION

Intraoperatively defined tumor characteristics played a critical role in identifying the subset of patients with an increased risk of postoperative deficits. By selectively pursuing an NTR rather than a GTR, neurological morbidity was reduced significantly without significantly increasing the rate of tumor recurrence.