Anterior clinoidal meningiomas: functional outcome after microsurgical resection in a consecutive series of 106 patients

Prognostic Factors in the Surgery of Clinoidal Meningiomas

INTRODUCTION

Clinoidal meningiomas are currently among the intracranial meningiomas with the greatest neurosurgical complexity, morbidity, and mortality associated with their resection. The worldwide literature has described tumor size (>4 cm³), patient age (>60 years), and invasion of the cavernous sinus as factors associated with a worse clinical outcome following surgery.

METHODS

We describe the series of cases of patients with clinoidal meningiomas who underwent microsurgical resection at our institution between January 2014 and March 2019. The intention was to analyze the multiple preoperative variables, such as the patient's demographic, tumor, and surgical characteristics, such as the Al-Mefty Classification to find a relationship with the patient's clinical outcome during their postoperative follow-up.  Results: Death occurred in 4.8% of the cases. Postoperative morbidity was documented in 42.9%, the most frequent being ophthalmoparesis, followed by worsening of visual acuity, and new onset motor deficits. Radiological characteristics were assessed based on preoperative MRI. The maximum diameter, midline shift, invasion of the cavernous sinus, arterial encasement, and peritumoral edema were evaluated. Average intraoperative bleeding was 1.3 L. The most frequent histological grade was World Health Organization (WHO) grade 1 in 85.6% of the cases. Complete resection was obtained in 52.4% of the cases; 42.8% received fractionated stereotactic radiotherapy after surgery for disease control, and one received radiosurgery. Recurrence occurred in 33.3%. The average follow-up in months was 23.8.  Conclusions: Demographic factors and tumor characteristics in clinoidal meningioma surgery are related to the subtype of meningioma according to the Al-Mefty Classification and impact directly the degree of resection, progression of the disease, and degree of postoperative complications. To achieve maximal resection while minimizing morbidity and mortality, these factors must be considered to decide on an appropriate approach and specific plan for each case.

The factors influencing postoperative efficacy of anterior clinoidal meningioma treatment and an analysis of best-suited surgical strategies

Objective

To explore the influence of the type of anterior clinoidal meningioma on surgical strategy planning, surgical approach selection, and postoperative efficacy.

Patients and methods

We conducted a retrospective analysis of the clinical data of 63 cases, including data on visual function, extent of tumor resection, and postoperative follow-up. Grade I and II approaches were selected according to the type of tumor. A univariate analysis of the factors influencing the extent of tumor resection, postoperative visual function, and postoperative relapse and complications was conducted.

Results

Simpson Grade I–II total resection was seen in 48 cases (76.2%), with an overall relapse/progression rate of 12.7%. The tumor type and texture and the relationship between the tumors and adjacent structures were the main factors influencing total tumor resection (P < 0.01). The overall postoperative visual acuity improvement, stabilization rate, and deterioration rate were 76.2, 15.9, and 7.9%, respectively. Postoperative visual acuity level was significantly correlated with preoperative visual acuity level and tumor type (P < 0.01).

Conclusions

Determining the type of tumor at a preoperative level and whether the optic canal and cavernous sinus are invaded can aid in the planning of detailed individualized surgical strategies.

Extradural Clinoidectomy in Clinoidal Meningiomas: Analysis of the Surgical Technique and Evaluation of the Clinical Outcome

The surgical treatment of clinoidal meningiomas is currently still discussed in the literature. Different surgical approaches have been proposed and evaluated, in multiple studies, in order to improve the surgical outcomes. The aim of this study is to evaluate the advantages of extradural clinoidectomy in the context of tumor removal radicality for visual function improvement. A retrospective analysis was performed on 74 patients—of which 26 patients with clinoidal meningiomas were in group III, according to Al Mefty classification—who underwent surgery at the Policlinico Umberto I Hospital between 2000 and 2019. Further, extradural clinoidectomy was performed on 15 patients (Group A), and 11 patients underwent the pterional approach only (Group B). Additionally, visual impairment was present in all 26 patients before surgery. Next, visual function assessment was performed on all patients, both in presurgery and postsurgery. Radiological follow up was performed at 3 and 6 months, and then every 12 months. Gross Total Resection (GTR) was achieved in 13/15 (86.7%) patients who underwent clinoidectomy, and in 4/11 (36.4%) patients who did not undergo clinoidectomy. Visual function improvement was achieved in 12/15 (80%) patients who underwent clinoidectomy and in 4 of 11 (36.4%) who did not undergo clinoidectomy. According to our study, extradural clinoidectomy is the most suitable method for facilitating the gross total resection of clinoidal meningiomas. Our experience and data suggest that a higher rate of total resection and, subsequently, the best visual outcomes are achieved. Extradural drilling via the anterior clinoid process reveals a wider surgical corridor for meticulous tumor resection.

Surgical management of anterior clinoidal meningiomas: consensus statement on behalf of the EANS skull base section

BACKGROUND

The optimal management of clinoidal meningiomas (CMs) continues to be debated.

METHODS

We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of these tumors. The data from the literature along with contemporary practice patterns were discussed within the task force to generate consensual recommendations.

RESULTS AND CONCLUSION

This article represents the consensus opinion of the task force regarding pre-operative evaluations, patient's counselling, surgical classification, and optimal surgical strategy. Although this analysis yielded only Class B evidence and expert opinions, it should guide practitioners in the management of patients with clinoidal meningiomas and might form the basis for future clinical trials.

Stereotactic radiosurgery for clinoid meningiomas: a multi-institutional study

PURPOSE

Resection of clinoid meningiomas can be associated with significant morbidity. Experience with stereotactic radiosurgery (SRS) for clinoid meningiomas remains limited. We studied the safety and effectiveness of SRS for clinoid meningiomas.

METHODS

From twelve institutions participating in the International Radiosurgery Research Foundation, we pooled patients treated with SRS for radiologically suspected or histologically confirmed WHO grade I clinoid meningiomas.

RESULTS

Two hundred seven patients (median age: 56 years) underwent SRS for clinoid meningiomas. Median treatment volume was 8.02 cm³, and 87% of tumors were immediately adjacent to the optic apparatus. The median tumor prescription dose was 12 Gy, and the median maximal dose to the anterior optic apparatus was 8.5 Gy. During a median post-SRS imaging follow-up of 51.1 months, 7% of patients experienced tumor progression. Greater margin SRS dose (HR = 0.700, p = 0.007) and pre-SRS radiotherapy (HR = 0.004, p < 0.001) were independent predictors of better tumor control. During median visual follow-up of 48 months, visual function declined in 8% of patients. Pre-SRS visual deficit (HR = 2.938, p = 0.048) and maximal radiation dose to the optic apparatus of ≥ 10 Gy (HR = 11.297, p = 0.02) independently predicted greater risk of post-SRS visual decline. Four patients experienced new post-SRS cranial nerve V neuropathy.

CONCLUSIONS

SRS allows durable control of clinoid meningiomas and visual preservation in the majority of patients. Greater radiosurgical prescription dose is associated with better tumor control. Radiation dose to the optic apparatus of ≥ 10 Gy and visual impairment before the SRS increase risk of visual deterioration.

How I do it: total resection of a giant sphenoclinoidal meningioma with normalization of near blind vision

BACKGROUND

Resection of giant sphenoclinoidal meningiomas (SCLM) remains difficult. We discuss a patient presenting with right eye near blindness who underwent total removal of a giant SCLM, resulting in normal vision and no recurrence.

METHOD

Utilizing frontotemporal craniotomy, devascularization, debulking, and detachment was achieved. Microdissection of tumor off the optic nerve and carotid perforators was accomplished, resulting in total resection, visual normalization, and no deficits using efficient face-to-face microscope set-up, 2-surgeon 4-hand technique, and double bipolar-suction arrangement.

CONCLUSION

Frontotemporal craniotomy was adequate. Preservation of the optic nerve and carotid artery is key. Meticulous microsurgical techniques and refined instruments are important for success.

Preserved arachnoid membrane acts as a predictor of postoperative visual improvement in clinoidal meningioma

OBJECTIVES

Improvement of patient visual outcome is very important in the treatment of clinoidal meningioma (CLM). The purpose of this study is to determine the association between arachnoid preservation and visual outcome.

PATIENTS

Fifteen patients with CLMs that caused visual impairment underwent surgery in our hospital. The patients included 4 men and 11 women, and the mean age was 53.3 years.

METHODS

The clinical findings of these patients were retrospectively reviewed. We divided the patients into two groups based on the presence or absence of the arachnoid membrane. Group 1 comprised cases in which arachnoid preservation was intraoperatively confirmed. Group 2 comprised cases in which the arachnoid membrane was not preserved. The Landolt C chart was used to evaluate visual acuity, and dynamic visual field tests using Goldmann perimetry were used to evaluate the visual field. Results were compared before and after surgery.

RESULTS

The visual acuity of the ipsilateral eye was significantly improved in Group 1 (p = 0.038). There were no other significant differences between the two groups in terms of tumor volume, patient age, and symptom duration.

CONCLUSIONS

Patients in which arachnoid preservation could be intraoperatively confirmed had good improvement in visual acuity. Further research with an increased number of cases is needed to confirm these findings.

Extradural anterior clinoidectomy in surgical management of clinoidal meningiomas

Background

Despite the recent advances in skull base surgery, microsurgical techniques, and neuroimaging, yet surgical resection of clinoidal meningiomas is still a major challenge. In this study, we present our institution experience in the surgical treatment of anterior clinoidal meningiomas highlighting the role of extradural anterior clinoidectomy in improving the visual outcome and the extent of tumor resection. This is a prospective observational study conducted on 33 consecutive patients with clinoidal meningiomas. The surgical approach utilized consisted of extradural anterior clinoidectomy, optic canal deroofing with falciform ligament opening in all patients. The primary outcome assessment was visual improvement and secondary outcomes were extent of tumor resection, recurrence, and postoperative complications.

Results

The study included 5 males and 28 females with mean age 49.48 ± 11.41 years. Preoperative visual deficit was present in 30 (90.9%) patients. Optic canal involvement was present in 24 (72.7%) patients, ICA encasement was in 16 (48.5%), and cavernous sinus invasion in 8 (24.2%). Vision improved in 21 patients (70%), while 6 patients (20%) had stationary course and 1 patient (3%) suffered postoperative new visual deterioration. Gross total resection was achieved in 24 patients (72.7%). The main factors precluding total removal were cavernous sinus involvement and ICA encasement. Mortality rate was 6.1%; mean follow-up period was 27 ± 13 months.

Conclusions

In this series, the use of extradural anterior clinoidectomy provided a favorable visual outcome and improved the extent of resection in clinoidal meningioma patients.

Advances in Multidisciplinary Management of Skull Base Meningiomas

The surgical management of Skull Base Meningiomas (SBMs) has radically changed over the last two decades. Extensive surgery for patients with SBMs represents the mainstream treatment; however, it is often challenging due to narrow surgical corridors and proximity to critical neurovascular structures. Novel surgical technologies, including three-dimensional (3D) preoperative imaging, neuromonitoring, and surgical instruments, have gradually facilitated the surgical resectability of SBMs, reducing postoperative morbidity. Total removal is not always feasible considering a risky tumor location and invasion of surrounding structures and brain parenchyma. In recent years, the use of primary or adjuvant stereotactic radiosurgery (SRS) has progressively increased due to its safety and efficacy in the control of grade I and II meningiomas, especially for small to moderate size lesions. Patients with WHO grade SBMs receiving subtotal surgery can be monitored over time with surveillance imaging. Postoperative management remains highly controversial for grade II meningiomas, and depends on the presence of residual disease, with optional upfront adjuvant radiation therapy or close surveillance imaging in cases with total resection. Adjuvant radiation is strongly recommended in patients with grade III tumors. Although the currently available chemotherapy or targeted therapies available have a low efficacy, the molecular profiling of SBMs has shown genetic alterations that could be potentially targeted with novel tailored treatments. This multidisciplinary review provides an update on the advances in surgical technology, postoperative management and molecular profile of SBMs.

Stereotactic Radiosurgery for Perioptic Meningiomas: An International, Multicenter Study

BACKGROUND

Stereotactic radiosurgery (SRS) is increasingly used for management of perioptic meningiomas.

OBJECTIVE

To study the safety and effectiveness of SRS for perioptic meningiomas.

METHODS

From 12 institutions participating in the International Radiosurgery Research Foundation (IRRF), we retrospectively assessed treatment parameters and outcomes following SRS for meningiomas located within 3 mm of the optic apparatus.

RESULTS

A total of 438 patients (median age 51 yr) underwent SRS for histologically confirmed (29%) or radiologically suspected (71%) perioptic meningiomas. Median treatment volume was 8.01 cm3. Median prescription dose was 12 Gy, and median dose to the optic apparatus was 8.50 Gy. A total of 405 patients (93%) underwent single-fraction SRS and 33 patients (7%) underwent hypofractionated SRS. During median imaging follow-up of 55.6 mo (range: 3.15-239 mo), 33 (8%) patients experienced tumor progression. Actuarial 5-yr and 10-yr progression-free survival was 96% and 89%, respectively. Prescription dose of ≥12 Gy (HR: 0.310; 95% CI [0.141-0.679], P = .003) and single-fraction SRS (HR: 0.078; 95% CI [0.016-0.395], P = .002) were associated with improved tumor control. A total of 31 (10%) patients experienced visual decline, with actuarial 5-yr and 10-yr post-SRS visual decline rates of 9% and 21%, respectively. Maximum dose to the optic apparatus ≥10 Gy (HR = 2.370; 95% CI [1.086-5.172], P = .03) and tumor progression (HR = 4.340; 95% CI [2.070-9.097], P < .001) were independent predictors of post-SRS visual decline.

CONCLUSION

SRS provides durable tumor control and quite acceptable rates of vision preservation in perioptic meningiomas. Margin dose of ≥12 Gy is associated with improved tumor control, while a dose to the optic apparatus of ≥10 Gy and tumor progression are associated with post-SRS visual decline.

Clinoidal meningiomas

Meningiomas that arise at the anterior clinoid process are termed clinoidal meningiomas and are characterized by unique anatomopathologic correlates that result in unique clinical behavior. According to their site of origin, clinoidal meningiomas can be further divided into three subgroups, which also differ in their clinical presentation and surgical outcome. Clinoidal meningiomas are centered on the anterior clinoid process and grow upward with a small pedicle while causing hyperostosis of the anterior clinoid process itself. The optic nerve is frequently compressed and visual symptoms occur early and in most cases. Upon surgical resection, visual symptoms improve in a significant portion of patients. Cavernous sinus invasion is infrequent. With increasing size, however, clinoidal meningiomas tend to invade surrounding neurovascular structures including distal carotid branches, which results in poor surgical outcome. Most clinoidal meningioma cases are managed with surgery where the anterior clinoid process is also removed along with the tumor either with an extradural or an intradural approach. Standard as well as minimal invasive and skull base approaches are advocated by different groups, but the results are comparable. Surgical results are very good in most cases with low mortality and morbidity. Invasion of the internal carotid artery, optic nerve, or distal carotid branches increase the risk of a postoperative residual. Recurrences are observed and usually managed with Gamma-Knife radiosurgery.

Postoperative Long-Term Independence Among the Elderly With Meningiomas: Function Evolution, Determinant Identification, and Prediction Model Development

Background

Maintenance of postoperative long-term independence has value for older adults who undergo surgical procedures. However, independence has barely caught attention for the elderly with meningiomas. Preventing postoperative long-term independence decline in this population necessitates the identification of the factors related to this outcome and minimizing their implications. Therefore, we assessed the independence evolution and identified potential determinants and population.

Materials and Methods

From 2010 to 2016, elderly meningioma patients (≥65 years old) undergoing operation at Beijing Tiantan Hospital were included in our study. The primary outcome was 3-year (i.e., long-term) postoperative independence measured by Karnofsky performance scale (KPS) score. We used univariate and multivariate analyses to determine the risk factors for postoperative long-term independence, and nomogram was established.

Results

A total of 470 patients were included eligibly. The distribution in each KPS was significantly different before and 3 years after resection (P < 0.001). Especially in patients with preoperative KPS 80 and 70, only 17.5 and 17.3% of the patients kept the same KPS after 3 years, and the remaining patients experienced significant polarization. The most common remaining symptom cluster correlated with postoperative long-term independence included fatigue (R = −0.795), memory impairment (R = −0.512), motor dysfunction (R = −0.636) and communication deficits (R = −0.501). Independent risk factors for postoperative long-term non-independence included: advanced age (70–74 vs. 65–69 OR: 2.631; 95% CI: 1.545–4.481 and ≥75 vs. 65–69 OR: 3.833; 95% CI: 1.667–8.812), recurrent meningioma (OR: 7.791; 95% CI: 3.202–18.954), location in the skull base (OR: 2.683; 95% CI: 1.383–5.205), tumor maximal diameter >6 cm (OR: 3.089; 95% CI: 1.471–6.488), nerves involved (OR: 3.144; 95% CI: 1.585–6.235), high risk of WHO grade and biological behavior (OR: 2.294; 95% CI: 1.193–4.408), recurrence during follow-up (OR: 10.296; 95% CI: 3.253–32.585), lower preoperative KPS (OR: 0.964; 95% CI: 0.938–0.991) and decreased KPS on discharge (OR: 0.967; 95% CI: 0.951–0.984) (P < 0.05). The discrimination and calibration of the nomogram revealed good predictive ability (C-index: 0.810).

Conclusion

Elderly meningioma patients might present significant polarization trend in maintaining long-term independence after surgery. Our findings will be helpful for guiding surgical management for the elderly with meningioma and provide proposals for early functional rehabilitation.

Surgical Strategies and Clinical Outcome of Large to Giant Sphenoid Wing Meningiomas: A Case Series Study

Large to giant sphenoid wing meningiomas (SWMs) remain surgically challenging due to frequent vascular encasement and a tendency for tumoral invasion of the cavernous sinus and optic canal. We aimed to study the quality of resection, postoperative clinical evolution, and recurrence rate of large SWMs. This retrospective study enrolled 21 patients who underwent surgery between January 2014 and December 2019 for SWMs > 5 cm in diameter (average 6.3 cm). Tumor association with cerebral edema, extension into the cavernous sinus or optic canal, degree of encasement of the major intracranial arteries, and tumor resection grade were recorded. Cognitive decline was the most common symptom (65% of patients), followed by visual decline (52%). Infiltration of the cavernous sinus and optical canal were identified in five and six patients, respectively. Varying degrees of arterial encasement were seen. Gross total resection was achieved in 67% of patients. Long-term follow-up revealed improvement in 17 patients (81%), deterioration in two patients (9.5%), and one death (4.7%) directly related to the surgical procedure. Seven patients displayed postoperative tumor progression and two required reintervention 3 years post initial surgery. Tumor size, vascular encasement, and skull base invasion mean that, despite technological advancements, surgical results are dependent on surgical strategy and skill. Appropriate microsurgical techniques can adequately solve arterial encasement but tumor progression remains an issue.

Mini-Pterional Craniotomy and Extradural Clinoidectomy for Clinoid Meningioma: Optimization of Exposure Using Augmented Reality Template: 2-Dimensional Operative Video

A "keyhole" approach to a deep-lying skull base lesion, as such a clinoid meningioma, can be a daunting challenge.1-3 The minimally invasive exposure must be precisely placed and adequately wide to accomplish the surgical goal. Surgical rehearsal in virtual reality (VR) can not only increase the confidence of the surgeon through practice on patient-specific anatomy,4 but it can also generate navigation-integrated templates to ensure precise placement and adequate bone openings. In this operative video, we demonstrate the use of an augmented reality (AR) template in a 69-yr-old woman with a growing clinoid meningioma. The 3-dimensional, VR rendering (SNAP VR360, Surgical Theater Inc, Cleveland, Ohio) of her right clinoid meningioma was used in surgical rehearsal for the mini-pterional approach with extradural clinoidectomy. The optimal opening was saved as a VR file and, at surgery, projected into the eye-piece of the navigation-tracked microscope (Synchronized AR v3.8.0, Surgical Theater Inc). In this manner, the surgical opening in the template was visible in AR on the patient's anatomy in real time during surgery. The template enhanced the planning of the incision and soft-tissue exposure, guided the drilling of the sphenoid wing, facilitated the extradural clinoidectomy,5 and ultimately facilitated the accomplishment of the surgical goal of total resection of the meningioma. With this application of novel technology, the surgeon is no longer using navigation to get her/his bearings. Instead, the surgeon is using AR-enhanced navigation to duplicate a plan that is known to work. This is a fundamental paradigm shift.  Patient consent was obtained prior to the creation of the video and is available on request.

Microsurgical Transcranial Approach of 112 Paraoptic Meningiomas: A Single-Center Case Series

BACKGROUND

Predictors of visual outcomes after optic nerve decompression are controversial.

OBJECTIVE

To identify the predictors of poor visual outcomes after surgery of meningiomas responsible of a compressive optic neuropathy.

METHODS

We focused on paraoptic meningiomas (POMs), which gathered tuberculum sellae meningiomas (TSMs) and anterior clinoid meningiomas (ACMs) responsible for visual impairment or threatening visual function, that underwent surgery at our institution between January 2009 and December 2015 and analyzed the clinical and radiological findings of our patients.

RESULTS

Among 112 patients who underwent surgery for a POM, a preoperative visual deficit was present in 108 patients (96.4%). Six months after surgery, 79 patients (70.5%) had a visual improvement, 15 patients (13.4%) had an unchanged vision, and 18 patients (16.1%) had deteriorated vision. A preoperative visual deficit of 6 mo or more was a strong predictor of poor visual outcome after surgery (P = .034). Poor visual outcome after surgery was not significantly related to the size of the tumor (P = .057), the age of the patient (P = .94), or the tumor extension into the optic canal (P = .47).

CONCLUSION

The duration of preoperative visual deficit was found to be a strong predictor of poor visual outcomes after surgery in POMs Other predictors of poor visual outcomes are still needed and are currently under evaluation in a prospective study at our institution.

Management of incidental anterior skull base large and giant meningiomas in elderly patients

INTRODUCTION

The incidence of meningiomas among the elderly is considered to be high, and are at increased risk of severe morbidity and mortality following surgery due to their aging physiology and unexpected comorbidities. This study aimed to evaluate the optimal management strategies of meningiomas in elderly patients.

METHODS

We retrospectively analyzed 150 patients with incidental large (≥ 3 cm) and giant (≥ 6 cm) anterior skull base meningiomas from 2009 to 2018. These patients were divided into elderly group (≥ 65 years, n = 70) and younger group (< 65 years, n = 80). Information of patients with regard to their medical records, operative details, relevant imaging, and follow-up data were obtained from their respective electronic medical records.

RESULTS

The elderly patients had significantly longer length of hospital stay (15.9 ± 3.5) compared to younger patients (13.6 ± 3.6, P < 0.001). Karnofsky Performance Scale (KPS) at discharge was significantly lower in elderly group when compared to younger group (P = 0.04). However, the KPS at 1-year after surgery was similar between the two groups. In addition, there was no significant difference in the incidence of surgical complications between the two groups. Multivariate regression analysis of postoperative complications revealed blood loss ≥ 800 mL (P = 0.007) and BMI (< 18.5 or ≥ 24, P < 0.001) as risk factors, rather than age.

CONCLUSIONS

Surgical resection in elderly patients with incidental anterior skull base large and giant meningiomas is considered to be a safe and effective therapeutic option owing to acceptable mortality, postoperative complications and postoperative clinical outcomes.

Anterior Clinoidal Meningiomas: Meningeal Anatomical Considerations and Surgical Implications

Objective: Surgical removal of anterior clinoidal meningiomas (ACMs) remains a challenge because of its complicated relationship with surrounding meninges, major arteries and cranial nerves. This study aims to define the meningeal structures around the anterior clinoid process (ACP) and its surgical implications.

Methods: Five dry skulls and 19 cadavers were used in the anatomical study. Cadavers were prepared as transverse, coronal, and sagittal plastinated sections, and the meningeal architecture around the ACP was studied with dissecting and confocal microscopies. The database of meningiomas in one single center was retrospectively reviewed, and the patients with ACMs were collected for clinical analysis.

Results: The superior, lateral, medial surfaces, and the tip of ACP were covered by different layers and types of meninges. The ACMs were classified into four main types based on the sites of origin, possible extending pathways following meningeal dura. In the retrospective cohort of 131 ACMs, the percentage of types I, IIa, IIb, III, and IV were 42.0% (55/131), 19.8% (26/131), 9.2% (12/131), 16.8% (22/131), and 12.2% (16/131), respectively. We found that types IIa and I had higher chances for achieving Simpson grade 1–2 resection (92.3 and 85.4%, respectively), followed by type III (54.5%) and type IV (31.3%), while type IIb showed little chance of Simpson grade 1–2 resection. Univariate and multivariate analyses revealed ACM classification and tumor size (<3 cm) to be independent risk factors for achieving more extensive resection.

Conclusion: The meningeal architecture around the ACP may guide and determine the origin and extension of ACMs. The classification based on the meningeal architecture helps to understand surgical anatomy as well as predicting surgical outcomes.

Extended Pterional Approach for Medial Sphenoid Wing Meningioma: A Series of 47 Patients

Background  To describe our operative strategy and analyze its safety and effectiveness for the removal of medial sphenoid wing meningiomas (MSWMs) through the extended pterional approach. Method  We identified 47 patients with MSWMs who were operated using this approach between 1986 and 2016. Medical charts, operative reports, imaging results, and clinical follow-up evaluations were reviewed and retrospectively analyzed. Results  No surgical mortality was observed in this sample. Gross total resection was achieved in 30 (63.8%) patients. Intradural clinoidectomy was performed in 16 (34%) patients. The median length of follow-up was 8.5 years (range, 1-30 years). Conclusion  The extended pterional approach associated with microsurgery techniques provided excellent results for the removal of MSWMs.

Surgery for posterior fossa meningioma: elevated postoperative cranial nerve morbidity discards aggressive tumor resection policy

Radical excision of meningioma is suggested to provide for the best tumor control rates. However, aggressive surgery for meningiomas located at the posterior cranial fossa may lead to elevated postoperative morbidity of adjacent cranial nerves which in turn worsens patients' postoperative quality of life. Therefore, we analyzed our institutional database with regard to new cranial nerve dysfunction as well as postoperative cerebrospinal fluid (CSF) leakage depending on the extent of tumor resection. Between 2009 and 2017, 89 patients were surgically treated for posterior fossa meningioma at the authors' institution. Postoperative new cranial nerve dysfunction as well as CSF leakage were stratified into Simpson grade I resections with excision of the adjacent dura as an aggressive resection regime versus Simpson grade II-IV tumor removal. Simpson grade I resections revealed a significantly higher percentage of new cranial nerve dysfunction immediately after surgery (39%) compared with Simpson grade II (11%, p = 0.01) and Simpson grade II-IV resections (14%, p = 0.02). These observed differences were also present for the 12-month follow-up (27% Simpson grade I, 3% Simpson grade II (p = 0.004), 7% Simpson grades II-IV (p = 0.01)). Postoperative CSF leakage was present in 21% of Simpson grade I and 3% of Simpson grade II resections (p = 0.04). Retreatment rates did not significantly differ between these two groups (6% versus 8% (p = 1.0)). Elevated levels of postoperative new cranial nerve deficits as well as CSF leakage following radical tumor removal strongly suggest a less aggressive resection policy to constitute the surgical modality of choice for posterior cranial fossa meningiomas.

Current decision-making in meningiomas

The incidence of meningiomas is rising and the number of incidental cases is increasing steadily. The efficiency and the safety of each treatment strategy are also improving over time. Therefore the indications to treat meningiomas are constantly changing. The aim of meningioma treatment is keeping the patient fully functional while achieving long-term relief or prevention from problems related to intracranial tumor growth. This chapter reviews the natural history and treatment results and aims to put together the information for the most objective decision-making in treating meningiomas. Factors acting on the treatment decision such as anatomical localization, symptomatology, variations in tumor biology, recurrence status, age and co-morbidities, operative gains, and patient preference are individually discussed.

Natural history of intracranial meningiomas

We know that the extent of resection is the greatest predictor of long-term survival. However, the potential tradeoff for gross total resection in difficult locations is diminished quality of life. Benign subtotally resected or small incidentally discovered meningiomas may be followed clinically especially in the elderly. In addition, radiosurgery plays a role in the treatment of meningiomas as a primary treatment modality, or as a salvage therapy. Decisions regarding management should be made with an understanding of the natural history and rate of growth. In this chapter we review the known meningioma epidemiology as well as the growth patterns of meningiomas based upon location.

High Mib-1-score correlates with new cranial nerve deficits after surgery for frontal skull base meningioma

Postoperative new cranial nerve deficits comprise severe concomitant morbidity in skull base meningioma surgery. Therefore, long-term cranial nerve integrity represents an important outcome measure. In the current study, we analyzed our institutional database in order to identify risk factors for postoperative new cranial nerve morbidity in the course of frontobasal meningioma surgery. Between 2009 and 2017, 195 patients were surgically treated for frontobasal meningioma at the authors' institution. Postoperative cranial nerve function was assessed immediately after surgery as well as 12 months postoperatively. A univariate and multivariate analysis was performed to identify factors influencing favorable postoperative cranial nerve outcome. Tumors with histological Mib-1-labeling indices > 5% were associated with a significantly higher percentage of new cranial nerve deficits immediately after surgery compared with those with Mib-1-labeling indices ≤ 5% (39% versus 20%, p = 0.029). Elevated Mib-1-labeling indices could be correlated with high CD68-positive macrophage staining (54% for Mib-1 index > 5% versus 19% for Mib-1 index ≤ 5%, p = 0.001). Elevated Mib-1-labeling index correlates with initial new cranial nerve dysfunction after resection of frontal skull base meningioma. With regard to elevated CD68-positive macrophage staining in high Mib-1-positive meningiomas, initial postoperative new cranial nerve morbidity might partly reflect macrophage-based inflammatory immune responses.

Multivariate risk factor analysis and literature review of postoperative deterioration in Karnofsky Performance Scale score in elderly patients with skull base meningioma

OBJECTIVE Elderly patients are particularly at risk for severe morbidity following surgery. Among the various risk factors, age and skull base location of meningioma are known to be poor prognostic factors in meningioma surgery. The authors conducted this study to analyze significant preoperative risk factors in elderly patients with skull base meningioma. METHODS A total of 265 elderly patients (≥ 65 years old) with meningioma were surgically treated at the authors' institute and affiliated hospitals between 2000 and 2016, and these cases were reviewed. Among them, 57 patients with skull base meningioma were evaluated. Among the various risk factors, the authors analyzed age, sex, Karnofsky Performance Scale (KPS) score, American Society of Anesthesiologists score, and tumor size, location, and pathology. Body mass index (BMI) and serum albumin were investigated as the frailty factors. The authors also reviewed 11 surgical studies of elderly patients ≥ 60 years old with meningioma. RESULTS The mean age was 72.4 ± 5.7 years, and 42 patients were female (73.6%). The mean size of meningioma was 36.6 ± 14.8 mm at the maximum diameter, and the mean follow-up period was 31.1 ± 31.5 months. (The continuous variables are expressed as the mean ± SD.) Histopathological investigation revealed a higher incidence (71.9%) of WHO Grade I. The rates of deterioration after surgery, at 3 months, and at 1 year were 33.3%, 37.3%, and 39.1%, respectively. Univariate analysis revealed location, preoperative KPS score, BMI level 2, and serum albumin level (p = 0.010, 0.017, 0.0012, and 0.0019, respectively) to be poor prognostic factors. Multivariate analysis revealed that location (p = 0.038) and BMI (p = 0.035) were risk factors for KPS score deterioration immediately after surgery. According to the 11 papers reviewed, the median rate (25th-75th percentile) of skull base-related location was 43.5% (39.6-47.75); for asymptomatic status the mean was 24%; and for mortality at 3 months and 1 year the medians were 6.3% (0.7-7.1) and 8% (4.8-9.4), respectively. CONCLUSION Careful preoperative assessment based on the frailty concept was essential for better outcome in elderly patients with skull base meningioma. The BMI is appropriate as a quantitative factor for measure of frailty, particularly in elderly individuals with skull base meningioma. Further prospective randomized controlled trials are necessary to validate frailty as a preoperative risk factor. Not only patient selection but also surgical timing was an important factor.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Usefulness of Preoperative Simulation in Skull Base Approach: A Case Report

Skull base approach is a neurosurgical challenge requiring dexterity of the operating surgeon for good postoperative outcome. In addition to the experience of the operating surgeon, adequate preoperative information of the tumor is necessary to ensure better outcome. In clinoid meningioma, it is sometimes difficult to determine its relationship with the surrounding structure and the feeding artery. Previously, preoperative simulation has been utilized to determine the intracranial course of the compressed nerves in relation to the petroclival meningioma. We report a case of clinoid meningioma where preoperative fusion of three dimensional computed tomography angiography (3D-CTA) and 3T-fast imaging employing steady-state acquisition (FIESTA) images was useful in determining the exact location of the feeding artery to devascularize the tumor and aid in surgery. Preoperative simulation with three-dimensional digital subtraction angiography (3D-DSA) and 3T-FIESTA fusion images can be a useful adjunct tool to supplement surgery and to train neurosurgical trainees.

Anterior Clinoid Metastasis Removed Extradurally: First Case Report

Background  We report a case of isolated metastasis on the anterior clinoid process (ACP) mimicking meningioma.

Clinical Presentation  A 58-year-old male presented with headaches, right-sided visual disturbances, and blurred and double vision. The cause of double vision was partial weakness of the right III nerve, resulting from compression of the nerve by “hypertrophied” tumor-involved right anterior clinoid. Medical history revealed two primary malignant tumors—male breast cancer and prostate cancer (diagnosed 6 and 18 months prior, respectively). The patient was treated with chemotherapy and showed no signs of active disease, recurrence, or metastasis. Postcontrast head magnetic resonance imaging (MRI) showed extra-axial well-bordered enhancing mass measuring 1.6 × 1.1 × 1 × 1 cm (anteroposterior, transverse, and craniocaudal dimensions) on the ACP, resembling a clinoidal meningioma. Extradural clinoidectomy with tumor resection was performed via right orbitozygomatic pretemporal skull base approach. Visual symptoms improved. Follow-up MRI showed no signs of tumor residual or recurrence.

Conclusion  This is the first case report of a metastasis of any kind on ACP. Metastasis should be included as a part of the differential diagnosis of lesions of the anterior clinoid. Extradural clinoidectomy is a safe and effective method in the treatment of these tumors.

Endoscopic transnasal suprasellar approach for anterior clinoidal meningioma: A case report and review of the literature

BACKGROUND

Anterior clinoidal meningiomas (ACM) are traditionally approached through transcranial routes. Due to their tendency to extend laterally and their proximity to vital neurovascular structures, the endoscopic transnasal suprasellar approach is still questionable. We present and describe an ACM case that underwent an endoscopic transnasal suprasellar approach, and provide a review of the literature and operative technique.

CASE DESCRIPTION

A 56 year-old lady who presented with chronic left-sided decreased vision. Brain imaging revealed a lesion measuring 9 × 10 × 11 mm attached to the left anterior clinoid process (ACP) and extending to the left optic canal. Lesion was compressing the left optic nerve (ON) and abutting the supraclinoid part of the left internal carotid artery (ICA). Utilizing the endoscopic transnasal suprasellar approach, the meningioma was resected and the optic canal was decompressed. Reconstruction was achieved using fascia lata, vomer bone, and nasoseptal flap. A lumbar drain was inserted perioperatively. Patient had no perioperative morbidity and retained vision in the affected eye.

CONCLUSIONS

Resection of selected ACMs can be safely achieved utilizing the endoscopic transnasal suprasellar approach. Although the literature lacks long-term outcome comparison between the transnasal and the traditional transcranial approaches, specifically addressing ACMs, this technique is becoming more popular over the last decade. More efforts should be directed towards implementing and reporting the endoscopic transnasal suprasellar approach for meningiomas of the anterior clinoid process.

[Early postoperative results of surgical treatment of patients with anterior clinoidal meningiomas]

Resection of anterior clinoidal meningiomas is a challenging task due to their localization, frequent involvement of the major cerebral arteries and cranial nerves, a high risk of postoperative neurological deficits, and low radicalness of surgery.

AIM

To evaluate the radicalness of microsurgical removal and a neurological deficit in the early postoperative period in patients with anterior clinoidal meningiomas.

MATERIAL AND METHODS

A total of 35 patients with anterior clinoidal meningiomas underwent surgery at the Department of Neurooncology of the Novosibirsk Federal Neurosurgical Center in the period from 2013 to July 2016. There were 29 (82.9%) females and 6 (17.1%) males. The mean patient age was 50.1 years (31-72 years). According to the Al-Mefty classification (1990), type 1 tumors occurred in 10 (28.6%) patients, type 2 tumors were in 22 (62.8%) patients, and type 3 tumors were in 3 (8.6%) patients. Twenty four (68.6%) patients had large (greater than 4.0 cm) tumors, 7 (20.0%) patients had medium (2.0-4.0 cm) tumors, and 4 (11.4%) patients had small (less than 2.0 cm) meningiomas. The tumor involved the major arteries in 21 (60.0%) patients.

RESULTS

The lateral supraorbital approach was used in 26 (74.3%) patients, and the pterional approach was used in 9 (25.7%) cases. The tumor was resected totally (Simpson II) in 25 (71.4%) cases and subtotally (Simpson IV, subtype A and B) in 10 (28.6%) patients. In the early postoperative period, cerebral symptoms regressed in 20 (57.1%) patients; visual acuity improved in 2 of 13 (15.4%) patients. Four (11.4%) patients developed IIIrd nerve palsy; 2 (5.7%) patients developed severe hemiparesis. The mortality rate was 2.9%.

CONCLUSION

The completeness of resection directly depends on the tumor consistency: soft meningiomas can be totally resected (Simpson II) with a good functional outcome. In the case of solid tumors, total resection may lead to serious ischemic disorders with a high risk of death.

Predictive factors for surgical outcome in anterior clinoidal meningiomas: Analysis of 59 consecutive surgically treated cases

Despite the advances in the microsurgical technique and anatomical understanding of the anterior and middle skull base, anterior clinoidal meningiomas are still challenging lesions to resect completely and safely due to their intimate relationship with vital neurovascular structures. We report predictive factors for tumor recurrence and postoperative complications based on surgical outcome of patients with anterior clinoidal meningiomas treated at our institution.Fifty-nine consecutive patients with anterior clinoidal meningioma who were surgically treated between March, 1993, and July, 2015, were reviewed retrospectively. For microsurgical tumor removal, orbitocranial or orbitozygomatic (78.0%), extended pterional (15.3%) and subfrontal approach (6.8%) were performed.The median follow-up duration was 54.1 months. Gross total resection (GTR, Simpson's grade I or II) was achieved in 38 patients (64.4%). The overall recurrence rate (new lesion in GTR cases and re-growth in non-GTR cases) was 18.6%. GTR (Hazard ratio [HR] 0.014, 95% confidence interval [CI] 0.001-0.256; P = .004), absence of internal feeder (HR 0.058, 95% CI 0.004-0.759; P = .030) and benign pathology (WHO grade I, HR 0.056, 95% CI 0.005-0.674; P = .023) were independent prognostic factors for recurrence-free. Fourteen patients (23.7%) developed permanent complications. The most common complication was cranial nerve injury (n = 6; 10.2%), followed by postoperative hemorrhage/infarction, hydrocephalus and infection. Larger size (≥ 40 mm) was significant as an independent predictive factor for permanent complication (HR 0.139, 95% CI 0.030-0.653; P = .012). Old age (≥60 years, P = .056) and peritumoral edema (thickness ≥ 5 mm, P = .303) did not reach statistical significance in multivariate analysis.In surgical resection of anterior clinoidal meningiomas, various clinicoradiological factors were related with resection degree, complication, and progression rate. Although our results showed acceptable resection degree and morbidity, mortality, and recurrence rate, compared to the results of past, anterior clinoidal meningioma remain as neurosurgical challenges because of their close contact to critical vascular and neural structures.

Hypofractionated stereotactic radiotherapy (HFSRT) for who grade I anterior clinoid meningiomas (ACM)

PURPOSE

While microsurgical resection plays a central role in the management of ACMs, extensive surgery may be associated with substantial morbidity particularly for tumors in intimate association with critical structures. In this study, we evaluated the use of HFSRT in the management of ACM.

MATERIALS AND METHODS

A total of 22 patients with ACM were treated using HFSRT. Frameless image guided volumetric modulated arc therapy (VMAT) was performed with a 6 MV linear accelerator (LINAC). The total dose was 25 Gy delivered in five fractions over five consecutive treatment days. Local control (LC) and progression free survival (PFS) rates were calculated using the Kaplan-Meier method. Common Terminology Criteria for Adverse Events, version 4.0 was used in toxicity grading.

RESULTS

Out of the total 22 patients, outcomes of 19 patients with at least 36 months of periodic follow-up were assessed. Median patient age was 40 years old (range 24-77 years old). Median follow-up time was 53 months (range 36-63 months). LC and PFS rates were 100 and 89.4 % at 1 and 3 years, respectively. Only two patients (10.5 %) experienced clinical deterioration during the follow-up period.

CONCLUSION

LINAC-based HFSRT offers high rates of LC and PFS for patients with ACMs.

Radiosurgical decompression for benign perioptic tumors causing compressive cranial neuropathies: a feasible alternative to microsurgery?

Several studies have reported the efficacy and safety of hypofractionated stereotactic radiosurgery (hSRS) in the treatment of benign perioptic tumors. This study went further and evaluated the feasibility of hSRS in the treatment of those causing compressive cranial neuropathies (CCNs) among perioptic tumors with special consideration of functional improvement. Twenty-six patients with CCNs (CN II = 19; CN III/IV/VI = 9; CN V = 3) caused by perioptic tumors underwent hSRS between 2011 and 2015. hSRS was delivered in five fractions with a median marginal dose of 27.8 Gy (≈14 Gy in a single fraction, assuming an α/β of three) to a tumor volume of 8.2 ± 8.3 cm³. All tumors except one shrank after treatment, with a mean volume decrease of 35 % (range 4-84 %) during the mean follow-up period of 20 months. In 19 patients (38 eyes) with compressive optic neuropathy, vision improved in 55.3 % of eyes (n = 21), was unchanged in 36.8 % (n = 14), and worsened in 7.9 % (n = 3) (2.6 % after excluding two eyes deteriorated due to transient tumor swelling). A higher conformity index (p = 0.034) and volume of the optic apparatus receiving >23.0 Gy (p = 0.019) were associated with greater tumor shrinkage. A greater decrease in tumor volume (p = 0.035) was associated with a better improvement in vision. Ophthalmoplegia and facial hypesthesia improved in six of nine (66.7 %) and three of three (100 %) patients, respectively. There was no newly developed neurological deficit. Decompressive SRS for benign perioptic tumors causing CCN is feasible using hypofractionation, representing a useful alternative to microsurgical resection.

Surgical Resectability of Skull Base Meningiomas

With recent advances in surgical technology such as preoperative imaging, neuro-monitoring, and surgical instruments, the surgical resectability of intracranial meningiomas has increased over the last two decades. This study reviewed clinical articles regarding the surgical treatment of meningiomas to clarify the role of surgical excision, with a focus on skull base meningiomas. We sub-classified clinical articles about skull base meningiomas into two categories (anterior and middle fossa meningiomas; and posterior fossa meningiomas) and reviewed papers in each category. In cases with anterior and middle fossa meningiomas, surgical resectability has reached a sufficient level to maximize functional preservation. In cases of posterior fossa meningioma, however, surgical respectability remains insufficient even with full use of recent surgical modalities. Continuous refining of operative procedures is required to obtain more satisfactory outcomes, especially for posterior fossa meningioma. In addition, recent long-term outcomes of stereotactic radiosurgery (SRS) were acceptable for controlling the skull base meningiomas. Therefore, combination with surgical excision and SRS should be considered in complicated skull base meningiomas.

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.

Optic nerve mobilization to enhance the exposure of the pituitary stalk during craniopharyngioma resection: early experience

OBJECT Preservation of the pituitary stalk and its vasculature is a key step in good postoperative endocrinological outcome in patients with craniopharyngiomas. In this article, the authors describe the surgical technique of medial optic nerve mobilization for better inspection and preservation of the pituitary stalk. METHODS This operative technique has been applied in 3 patients. Following tumor exposure via a frontolateral approach, the pituitary stalk could be seen partially hidden under the optic nerve and the optic chiasm. The subchiasmatic and opticocarotid spaces were narrow, and tumor dissection from the pituitary stalk under direct vision was not possible. The optic canal was therefore unroofed, the falciform ligament was incised, and the lateral part of the tuberculum sellae was drilled medial to the optic nerve. The optic nerve could be mobilized medially to widen the opticocarotid triangle, which enhanced visualization of and access to the pituitary stalk. RESULTS By using the optic nerve mobilization technique, the tumor could be removed completely, and the pituitary stalk and its vasculature were preserved in all patients. In 2 patients, vision improved after surgery, while in 1 patient it remained normal, as it was before surgery. The hormonal status remained normal after surgery in 2 patients. In the patient with preoperative hormonal deficiencies, improvement occurred early after surgery and hormonal levels were normal after 3 months. No approach-related complications occurred. CONCLUSIONS This early experience shows that this technique is safe and could be used as a complementary step during microsurgery of craniopharyngiomas. It allows for tumor dissection from the pituitary stalk under direct vision. The pituitary stalk can thus be preserved without jeopardizing the optic nerve.

Meningiomas of the Anterior Clinoid Process: Is It Wise to Drill Out the Optic Canal?

Introduction: Meningiomas of the anterior clinoid process are uncommon tumors, acknowledged by most experienced surgeons to be among the most challenging meningiomas to completely remove. In this article, we summarize our institutional experience removing these uncommon and challenging skull base meningiomas.

Methods: We analyzed the clinical outcomes of patients undergoing surgical removal of anterior at our institution over an 18-year period. We characterized the radiographic appearance of these tumors and related tumor features to symptoms and ability to obtain a gross total resection. We also analyzed visual outcomes in these patients, focusing on visual outcomes with and without optic canal unroofing.

Results: We identified 29 patients with anterior clinoid meningiomas who underwent surgical resection at our institution between 1991 and 2007. The median length of follow-up was 7.5 years (range: 2.0 to 18.6 years). Similar to others, we found gross total resection was seldom safely achievable in these patients. Despite this, only 1/20 of patients undergoing subtotal resection without immediate postoperative radiosurgery experienced tumor progression. The optic canal was unroofed in 18/29 patients in this series, while in 11/29 patients it was not. Notably, all five patients experiencing visual improvement underwent optic canal unroofing, while three of four patients experiencing visual worsening did not.

Conclusions:  These data provide some evidence suggesting that unroofing the optic canal in anterior clinoid meningiomas might improve visual outcomes in these patients.

Stereotactic radiosurgery for intracranial meningiomas: current concepts and future perspectives

Meningiomas are among the most common adult brain tumors. Although the optimal management of meningiomas would provide complete elimination of the lesion, this cannot always be accomplished safely through resection. Therefore, other therapeutic modalities, such as stereotactic radiosurgery (as primary or adjunctive therapy), have emerged. In the current review, we have provided an overview of the historical outcomes of various radiosurgical modalities applied in the management of meningiomas. Furthermore, we provide a discussion on key factors (eg World Health Organization grade, lesion size, and lesion location) that affect tumor control and adverse event rates. We discuss recent changes in our understanding of meningiomas, based on molecular and genetic markers, and how these will change our perspective on the management of meningiomas. We conclude by outlining the areas in which knowledge gaps persist and provide suggestions as to how these can be addressed.

Hypofractionated stereotactic radiation therapy in skull base meningiomas

To investigate the role of hypo-fractionated stereotactic radiation treatment (HSRT) in the management of skull base meningioma. Twenty-six patients were included in the study and treated with a dose of 30 Gy in 5 fractions with volumetric modulated arc therapy (RapidArc). Eighteen patients were symptomatic before treatment. Endpoints were local toxicity and relief from symptoms. Tumors were located in anterior skull base in 4/27 cases, in middle skull base in 12/27 and in posterior skull base in 11/27. HSRT was performed as first treatment in 17 (65 %) patients, in 9 (35 %) patients it followed a previous partial resection. Median follow up was 24.5 months (range 5-57 months). clinical remission of symptoms, complete or partial, was obtained in the vast majority of patients after treatment. Out of the 18 symptomatic patients, partial remission occurred in 9 (50 %) patients and complete remission in 9 (50 %). All asymptomatic patients retained their status after treatment. No severe neurologic toxicity grade III-IV was recorded. No increase of meningioma in the same site of treatment occurred; 16 (62 %) patients had stable disease and 9 (38 %) patients had tumor reduction. The mean tumor volume after treatment was 10.8 ± 17.8 cm(3) compared with 13.0 ± 19.1 cm(3) before treatment (p = 0.02). The mean actuarial OS was 54.4 ± 2.8 months. The 1- and 2-years OS was 92.9 ± 0.7 %. HSRT proved to be feasible for these patients not eligible to full surgery or to ablative radiation therapy. Local control and durability of results suggest for a routine application of this approach in properly selected cases.

Sphenoid wing meningiomas: Surgical strategies and evaluation of prognostic factors influencing clinical outcomes

OBJECTIVE

To study microsurgical technique and prognostic factors influencing clinical outcomes in a series of 53 patients with sphenoid wing meningiomas (SWMs).

MATERIALS AND METHODS

The clinical materials of 53 patients with sphenoid wing meningiomas treated microsurgically between January 2008 and January 2012 were analyzed retrospectively. Follow-up period ranged from 6 to 62 months (median, 34 months). Clinical outcomes including postoperative quality of life and recurrence rate were evaluated. Univariate and multivariate statistical analysis were performed among factors that might influence postoperative quality of life.

RESULTS

In our group, the mean age of patients was 49 years. Mean tumor size was 3.9cm. Total tumor resection was achieved in 38 cases (71.7%), subtotal in 10 cases (18.9%) and partial resection in 5 cases (9.4%). Within the follow-up period, ten patients (18.9%) had recurrence and three patients (5.7%) died. In univariate analysis, we found the postoperative Karnofshky Performance Score (KPS) improvement was determined by various factors, including extent of tumor resection, peritumoral edema, tumor blood supply, size, adhesion, encasement and preoperative KPS. However, multivariate analysis showed that complete resection, rich blood supply, adhesion to adjacent structure, encasement of neurovascular were independent predictive factors for worse postoperative KPS.

CONCLUSIONS

With the improved requirement of postoperative quality of life in patients, intentional incomplete resection should be considered as an acceptable treatment option. Multivariate analysis confirmed that incomplete resection, poor blood supply, lack of adhesion or encasement of adjacent structure were independent predictive factors for favorable postoperative quality of life. An individual treatment strategy could help improved quality of life.

Results of surgical treatment of anterior clinoidal meningiomas - our experiences

OBJECTIVE

Presentation of our experience in the treatment of anterior clinoidal meningiomas, including evaluation of factors that may affect early and long-term treatment outcomes.

METHODS

Thirty patients were operated with strategy of complete tumor resection using fronto-orbito-zygomatic approach. Outcomes were assessed by Glasgow Outcome Scale at discharge and by Karnofsky Performance Scale at follow-up.

RESULTS

There were 6 tumors in group I, 20 in group II, and 4 in group III according to Al-Mefty classification. Complete tumor resection (Simpson I or II) was achieved in 19 patients, incomplete resection (Simpson IV) in 11: due to strict tumor adhesion to cerebral arteries in 5 and tumor extension to cavernous sinus in 6 cases. Operative mortality was 6.7%. Visual acuity improved in six among nine patients with impaired vision but in no one among nine patients with blindness. Normal life activity (80-100 KPS) could be carried out by 88% patients at follow-up. Recurrence was observed in two (11.8%) patients after radical removal and progression of residual tumor in two (25%) after subtotal resection.

CONCLUSIONS

Complete tumor removal is possible with an acceptable risk of death and severe neurological deficits, except for cases with tumor extension to the cavernous sinus or strict tumor adhesion to cerebral arteries. Visual acuity improvement may be expected in two thirds of patients with impaired vision, but not in cases of blindness. In cases of incomplete tumor removal, use of stereotactic radiosurgery immediately after surgery seems justified.

Towards a hypermodern theory of meningioma surgery

In spite of significant improvements in patient outcomes, meningioma surgery continues to be associated with appreciable morbidity and variability in management schemes, suggesting an opportunity for improvement. In this article, we attempt to cross-pollinate our discipline with theoretical concepts and analytic frameworks from the field of cultural studies over the past several decades. We provide an overview of modernist, postmodernist, and hypermodernist thinking, the last of which emphasizes rapid progress, repeated recreation of dogmas, and data-driven decision-making. We subsequently demonstrate how the evolution of these schools of thought can be used to improve the analytic approach to comparative outcomes research in neurosurgery, with meningioma research as a principal example. We contend that with the renaissance of microsurgery and advent of improved technologies in meningioma management over recent years, modernist analytic methods are no longer adequate. Instead, we advocate for a new hypermodern paradigm that provides evidence-based answers to unresolved questions, minimizes unwarranted variability in clinical practice patterns, and provides a system for continuous assessment and reassessment of outcomes in the rapidly evolving environment of contemporary skull base neurosurgery. In particular, we discuss the relevance of historical case series from leading neurosurgeons for clinical decision-making, the value of seeking new data for longstanding clinical questions, the merits of radiosurgery versus open surgery, and the importance of recognizing tumor heterogeneity rather than simply stratifying them based on general characteristics such as tumor location. In turn, we lay a conceptual foundation for improving outcomes research in meningioma surgery.

Iatrogenic diplopia [corrected]

Diplopia is a very disturbing condition that has been reported as a complication of several surgical procedures. The following review aims to identify the ocular and nonocular surgical techniques more often associated with this undesirable result. Diplopia is reported as an adverse outcome of some neurosurgical procedures, dental procedures, endoscopic paranasal sinus surgery, and several ophthalmic procedures. The most common patterns and some recommendations in order to prevent and treat this frustrating outcome are also given.

Quality-of-Life after Anterior Skull Base Surgery: A Systematic Review

Background Improved treatment and survival of patients with skull base tumors has made the assessment of quality-of-life (QoL) in this population increasingly important. This article provides a comprehensive systematic review pertaining to QoL assessment in adults undergoing anterior skull base surgery. Methods We performed a literature search using the electronic databases of Ovid Medline and Embase. Additional articles were identified through a search using the phrase anterior skull base. Further articles were sought through hand-searching relevant journals and reference lists of identified articles. Results Our search strategy identified 29 articles for inclusion in our systematic review, with considerable variation between studies in population characteristics, methodological design and quality, follow-up length, and outcome assessment. The most commonly used QoL tools were the Karnofsky Performance Status and the Anterior Skull Base Questionnaire. QoL following anterior skull base surgery appears to improve beyond preoperative levels in the months after surgery. For patients undergoing endoscopic skull base surgery, the gain in QoL appears to be greater and may manifest earlier, with no clear long-term deleterious effect on sinonasal outcomes compared with open surgery. Conclusions QoL after anterior skull base surgery in adults appears to improve within several months of surgery, but earlier and to a larger extent if the endoscopic approach is used. Given the relative paucity and heterogeneity of anterior skull base tumors, large-scale prospective multicentre studies utilizing valid and reliable multidimensional QoL tools are required. This may result in improved patient care, by understanding patients' needs better and facilitating the provision of reliable outcome data for clinical trials.

Surgical techniques for the dissection of encased perforators in giant clinoidal meningiomas

BACKGROUND

Surgical treatment of giant clinoidal meningiomas remains a challenging task for neurosurgeons. Here, we present details of the surgical techniques for the dissection of encased perforators.

METHODS

The dissection of encased perforators is summarized as follows: (1) split the tumor above the encased arteries and perforators; (2) find the entrance and exit points of the perforators, and estimate the running course of the perforators within the tumor; (3) dissect and expose the perforators along the estimated line.

CONCLUSIONS

The surgical techniques described in this article will aid in achieving maximum tumor resection while preserving encased perforators.

Presurgical planning of feeder resection with realistic three-dimensional virtual operation field in patient with cerebellopontine angle meningioma

BACKGROUND

To devascularize meningiomas, the precise location of tumor attachment must be known. However, when a cerebellopontine angle (CPA) meningioma is in contact with many surrounding structures, it can be difficult to distinguish the most vascularized attachment (MVA) from other contact surfaces.

OBJECTIVE

To validate the usefulness of a virtual operation field (VOF) of a CPA meningioma by high-spatial-resolution three-dimensional computer graphics (hs-3DCG).

METHODS

Presurgical simulation with VOF was performed for eight CPA meningiomas to assess the MVA and the appropriate route to the main feeder. For hs-3DCG, the necessary preoperative radiographic images were fused. A hybrid model of volume and surface rendering was created from the fused images. The simulation results were compared with the operative results, and the MVA estimation rate was compared between VOF and contrast-enhanced fast imaging employing steady-state acquisition.

RESULTS

By using VOF, the point at which the main feeder penetrated the tumor was estimated in all cases, and using this information, the MVA was detected. All patients underwent resection of the main feeder in the same way as simulated preoperatively. Estimation rates of MVA were 37.5% in CE-FIESTA and 100% in VOF (p = 0.02, Fisher's exact test).

CONCLUSION

The hs-3DCG method was of sufficiently high quality to enable VOF of CPA meningioma. This method may facilitate estimation of MVA and the main feeder penetration point, and may aid in the determination of the most appropriate approach to the main feeder.

Surgical unroofing of the optic canal and visual outcome in basal meningiomas

BACKGROUND

To define from a series of surgically treated suprasellar, anterior clinoid, and sphenoid wing meningiomas, an unequivocal criterion for performing optic canal deroofing in patients with basal meningiomas with deteriorated vision.

METHODS

One hundred-fifty consecutive patients with suprasellar and parasellar meningiomas (44 tuberculum sellae, 46 clinoidal, and 60 spheno-orbital) who underwent surgery between 1988 and 2008 are retrospectively analyzed. The rate of preoperative visual deficit, the incidence of optic canal involvement, the related surgical management, and its influence on visual outcome are reviewed in all tumor localizations.

RESULTS

All 44 patients with tuberculum sellae meningiomas had variable preoperative visual impairment. All were operated on by transcranial approach. Unroofing of the optic canal was performed in the two cases with intracanalar tumor extension. Postoperatively, the visual function improved in 27 patients (61.4 %) and was unchanged in 17 (25 %). Among 46 patients with clinoidal meningiomas, visual dysfunction was found in 30 (65.2 %). The first 32 patients were operated on by classical pterional approach, with selective opening of the optic canal in six cases (group A), whereas all the last 14 underwent routine anterior clinoidectomy and opening of the optic canal (group B). The visual function improved postoperatively in 17 among 30 patients (56.7 %), with a significantly higher rate in group B cases (80 % versus 45 %). Among 60 patients with spheno-orbital meningiomas, 36 (60 %) had visual dysfunction and 43 (71.6 %) involvement of the optic canal. The visual function improved in 18 cases (50 %), was unchanged in 13 (36 %), and worsened in 5 (14 %). Lateral tumors had the lowest rate of optic canal involvement and a 100 % rate of visual improvement; on the other hand, all orbital apex and diffuse tumors had concentric invasion of the optic canal with a 18.6 % rate of visual worsening.

CONCLUSIONS

UOC seems to be a safe procedure not associated with immediate postoperative impairment of the vision. We recommend routine deroofing of the optic canal coupled with extradural anterior clinoidectomy in all clinoidal meningiomas in order to obtain early and complete exposure of both intradural and extradural segments of the optic nerve. For tuberculum sellae meningiomas, we advise to open the optic canal only in cases with intracanalar tumor extension. Finally, for spheno-orbital meningiomas, we recommend UOC through a cranio-orbital approach in almost all cases, except for lateral meningiomas, where the involvement of the lateral wall of the optic canal is rare and may be successfully managed through a lateral orbitotomy without craniotomy.