Long-term outcome and growth rate of subtotally resected petroclival meningiomas: experience with 38 cases

Neurosurgical treatment and outcome patterns in patients with meningioma in South Moravian region-a population-based study

INTRODUCTION

Meningiomas are usually slow-growing tumours, constituting about one third of all primary intracranial tumours. They occur more frequently in women. Clinical manifestation of meningiomas depends on their location, tumour size and growth rate. In most cases, surgical treatment is the procedure of choice. The success of this treatment is, however, associated with the radicality of the resection. Radiotherapy represents an additional or alternative treatment modality. Gamma knife surgery is another notable treatment method, especially in small and/or slow-growing tumours in eloquent areas or in elderly patients.

MATERIAL AND METHODS

Authors describe their experience with the diagnosis, treatment and outcome of the patients with meningioma (n = 857). Furthermore, they also assess the postoperative morbidity/mortality and recurrence rate.

RESULTS AND CONCLUSIONS

In view of the benign histology of meningiomas, the success of the treatment largely depends (besides the tumour grading) on the radicality of the resection. The emphasis is also put on appropriate follow-up of the patients. In certain patients, the watch and wait strategy should be also considered as a suitable treatment method.

Postoperative Complications and Neurological Deficits After Petroclival Region Meningioma Resection: A Case Series

BACKGROUND

Surgical management of meningiomas involving the petroclival junction remains a challenge because of nearby critical neurovascular structures.

OBJECTIVE

To describe surgical approach selection, outcomes, and factors associated with postoperative complications and neurological deficits in a series of patients undergoing resection of petroclival region meningiomas.

METHODS

Retrospective review of patients undergoing symptomatic petroclival region meningioma resection was performed. Logistic regression was performed to identify variables associated with postoperative complications and new neurological deficits.

RESULTS

Sixty-five patients underwent 54 one-stage and 11 two-stage resections with median follow-up of 51 months. Most tumors were World Health Organization grade 1 (90.8%), and the median volume was 23.9 cm 3 . Posterior petrosectomy and anterior petrosectomy were performed in 67.1% and 6.6% of operations, respectively. The gross or near total resection rate was 15.4%, and 8 patients (12.3%) progressed on follow-up. The surgical complication rate was 26.2% with no perioperative mortalities. Postoperatively, 45.8% of patients had new, persistent neurological deficits, with cranial nerves VII palsy being most common. On multivariate analysis, higher body mass index (odds ratio [OR]: 1.1, P = .04) was associated with risk of surgical complications. Longer operative time (OR: 1.4, P = .004) and staged procedures (OR: 4.9, P = .04) were associated with risk of new neurological deficit on follow-up, likely reflecting more challenging tumors. Comparing early vs later career surgeries performed by the senior author, rates of severe complications and neurological deficits decreased 23.1% and 22.3%, respectively.

CONCLUSION

Petroclival region meningiomas remain surgically challenging, but improved outcomes are seen with surgeon experience. These data help inform patients on perioperative morbidity risk and provide a guide for surgical approach selection.

Surgical management of large cerebellopontine angle meningiomas: long-term results of a less aggressive resection strategy

OBJECTIVE

Cerebellopontine angle (CPA) meningiomas present many surgical challenges depending on their volume, site of dural attachment, and connection to surrounding neurovascular structures. Assuming that systematic radical resection of large CPA meningiomas carries a high risk of permanent morbidity, the authors adopted an alternative strategy of optimal resection followed by radiosurgery or careful observation of the residual tumor and assessed the efficiency and safety of this approach to meningioma treatment management.

METHODS

This single-center retrospective cohort study included 50 consecutive patients who underwent surgery for meningioma between January 2003 and February 2020.

RESULTS

The most common main dural attachments of the meningiomas were posterior (42%) and superior (26%) to the internal auditory meatus. The suboccipital retrosigmoid route was the most routinely used (92%). At the last follow-up examination, 93% of the patients with normal preoperative facial nerve (FN) function retained good House-Brackmann (HB) grades of I and II, whereas 3 patients (7%) displayed intermediate HB grade III FN function. Hearing preservation was achieved in 86% of the patients who presented with preoperative serviceable hearing, and recovery after surgery was achieved in 19% of the patients experiencing preoperative hearing loss. In order to preserve all cranial nerve function, gross-total resection was obtained in 26% of patients. Of the 35 patients who had undergone subtotal resection, 20 (57%) had been allocated into a wait-and-rescan treatment approach and 15 (43%) underwent upfront Gamma Knife surgery (GKS). The mean postoperative tumor volume was 1.20 cm3 in the upfront GKS group and 0.73 cm3 in the wait-and-rescan group (p = 0.08). Tumor control was achieved in 87% and 55% of cases (p < 0.001), with a mean follow-up of 85 and 69 months in the GKS and wait-and-rescan groups, respectively. The 1-, 5-, and 7-year tumor progression-free survival rates were 100%, 100%, and 89% in the GKS group and 95%, 59%, and 47% in the wait-and-rescan group, respectively (p < 0.001).

CONCLUSIONS

Optimal nonradical resection of large CPA meningiomas provides favorable long-term tumor control and functional preservation. Adjuvant GKS does not carry additional morbidity and appears to be an efficient adjuvant treatment.

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.

Abordajes quirúrgicos de los meningiomas petroclivales Parte 2: revisión narrativa y lo que aprendimos con 30 casos

Antecedentes:

La resección quirúrgica de los meningiomas petroclivales es un desafío debido a su ubicación profunda y su relación con las estructuras neurovasculares vitales. Por lo general, son lesiones benignas, pero pueden involucrar o infiltrar huesos en la base del cráneo, la duramadre y el tronco encefálico. Esto hace que la extirpación total sea muy difícil o imposible sin causar déficits neurológicos. El objetivo de este estudio es revisar los abordajes quirúrgicos utilizados para tratar los meningiomas petroclivales y las lecciones que hemos aprendido en el manejo quirúrgico de 30 casos.

Métodos:

Serie de casos de 30 meningiomas petroclivales. Al comienzo de nuestra serie, utilizamos el abordaje petroso para todos los casos, pero con la adquisición de experiencia comenzamos a indicar cada vez más el abordaje retrosigmoideo, reservando los abordajes petrosos y cráneo-orbitocigomático para casos seleccionados.

Resultados:

Debido a la dificultad de acceso, los meningiomas petroclivales generalmente requieren diferentes abordajes quirúrgicos y presentan diferentes dificultades quirúrgicas. Hay tres abordajes principales: fronto-orbito-cigomático y variantes; petroso y variantes; y retrosigmoideo, pudiendo ser combinados. La elección del abordaje quirúrgico generalmente se basa en la ubicación y extensión del tumor, la forma del cráneo y la participación de las estructuras venosas, y la experiencia del cirujano.

Conclusión:

Los meningiomas petroclivales son raros y complejos en la base del cráneo. Elegir el abordaje correcto es crucial para un resultado quirúrgico exitoso.

A Retrospective Evaluation of the Retrosigmoidal Approach for Petroclival Meningioma Surgery and Prognostic Factors Affecting Clinical Outcome

Introduction

Petroclival meningioma (PCM) remains a major neurosurgical challenge. There are still controversial strategic treatment concepts about surgical approach, the extent of resection, and postoperative radiotherapy. We aimed to evaluate prognostic factors influencing the progression-free survival (PFS) rates of PCM, with a particular focus on the retrosigmoidal approach, the role of the extent of resection, and postoperative radiotherapy.

Methods

Eighty-nine patients with complete follow-up data were included. All patients were operated on via a retrosigmoidal approach, of whom 19 underwent gross total resection (GTR) and 70 underwent subtotal resection (STR). In the subgroups of tumors with infiltration of the cavernous sinus, 41 patients received near total resection (NTR) and 24 STR. Thirty-one patients received postoperative radiotherapy of the residual tumor and 58 were treated with surgery alone. Kaplan–Meier analyses and Cox regression were used to identify significant factors associated with treatment.

Results

GTR (p=0.0107) and postoperative radiotherapy (p=0.014) were associated with significantly improved PFS. Even the subgroup analysis of extended PCM with infiltration of the cavernous sinus (CS) showed an advantage for PFS after near total resection (NTR) (p=0.0017). The additional radiotherapy of the residual tumor in the CS in this subgroup also showed a beneficial effect on PFS (p=0.012).

Conclusion

The extension of surgical resection remains the most important prognostic factor in relation to oncological outcomes. However, the GTR of extended PCM with infiltration of the CS is associated with significant neurological morbidity and requires additional adjuvant therapy concepts. Postoperative radiotherapy is an important element in the treatment of the residual tumor after surgery.

Primary versus postoperative gamma knife radiosurgery for intracranial benign meningiomas: a matched cohort retrospective study

Objective

The aims of this study were to investigate the long-term outcomes of primary versus postoperative Gamma Knife radiosurgery (GKRS) for benign meningiomas.

Methods

Three hundred and forty meningioma patients underwent GKRS were retrospectively reviewed. Patients in the postoperative GKRS group were matched to those in the primary GKRS group, in a 1:1 ratio.

Results

The study consisted of 122 patients, including primary (n = 61) and postoperative (n = 61) GKRS group. Thirty-four patients (27.9%) occurred radiological progression after a median follow-up of 72.5 (range, 24.2–254.5) months. The median time to radiological progression was 85.1 (range, 20.7–205.1) months. The radiological progression-free survival (PFS) was 100%, 93%, 87%, and 49%, at 1, 3, 5, and 10 years respectively. Thirty-one patients (25.4%) occurred clinical progression. The clinical PFS was 92%, 89%, 84%, and 60%, at 1, 3, 5, and 10 years. In combined group, only max diameter ≥ 50 mm was associated with radiological (p = 0.020) and clinical PFS (hazard ratio [HR] = 2.896, 95% confidence interval [CI] = 1.280–6.553, p = 0.011). Twenty-five patients (20.5%) developed GKRS related adverse effects, including radiation-induced edema (n = 21). Non-skull base tumors (HR = 3.611, 95% CI = 1.489–8.760, p = 0.005) and preexisting peritumoral edema (HR = 3.571, 95% CI = 1.167–10.929, p = 0.026) were significantly related to radiation-induced edema in combined group. There was no significant difference in radiological PFS (p = 0.403), clinical PFS (p = 0.336), and GKRS related adverse effects (p = 0.138) between primary and postoperative GKRS groups.

Conclusions

Primary GKRS could provide similar radiological and clinical outcomes, as well as similar complication rate compared with postoperative GKRS. For selective benign meningioma patients (asymptomatic or mildly symptomatic tumors; unfavorable locations for surgical resection; comorbidities or an advanced age), GKRS could be an alternative primary treatment.

Mortality and morbidity in surgically treated patients with petroclival meningiomas: a systematic review and meta-analysis of case series

BACKGROUND

Reports on petroclival meningioma (PCM) surgical mortality and morbidity often deviate from established standards; as such, a comprehensive summary is lacking.

METHODS

Eligibility/sources. Peer-reviewed case series of at least 10 PCM patients identified from PubMed, Web of Science, Ovid, or Google Scholar. Outcomes. Primary: mortality, tumor recurrence, any cranial nerve deficit (CND); other: individual CNDs, other complications. Data synthesis. Random-effects meta-analysis/meta-regression [effects: surgical approach (supratentorial, S; infratentorial, I; combined, (C), average age and follow-up, sample size, and percent of patients with gross-total resection (GTR)] of logit-transformed proportions.

RESULTS

Data. 73 case-series/3553 patients. Mortality. Adjusted predicted mortalities of 2.4%, 2.5%, and 1.2% (50-month follow-up) for the S, I, and C approaches, respectively, with the upper limits of the 95% credibility intervals at 3.3%, 3.7%, and 3.6%, respectively. Recurrence. Adjusted predicted recurrences of 5.5%, 11.1%, and 12.0% (50-month follow-up and 57% GTR) for the S, I, and C approaches, respectively; recurrence was positively associated with follow-up period and negatively associated with having received GTR. At all covariates at median values but at GTR 90% predictions: 3.1% (95%CI 3.1-9.8), 6.3% (3.8-10.4), and 6.9% (3.4-13.2) with the S, I, and C; prediction credibility intervals 1-4% and 22.4%. Any CND. Adjusted predicted probabilities of 37.2%, 23.4%, and 29.5% (at median covariate values) for the S, I, and C approaches, respectively; prediction credibility intervals ranged from <10% to 78%. Other outcomes. The most common individual CNDs were nVII (14.4%), nV (11.5%), and nIII (10.2%); other common complications included motor deficit (10.8%), infection (9.8%), and CSF leak (7.5%).

CONCLUSION

This is the first systematic review on PCM surgical mortality, recurrence, and morbidity. Outcomes differ between surgical approaches and reporting quality varies greatly.

Stereotactic radiosurgery for asymptomatic petroclival region meningiomas: a focused analysis from the IMPASSE study

BACKGROUND

The optimal management of asymptomatic, petroclival meningiomas remains incompletely defined. The purpose of this study was to evaluate the safety and efficacy of upfront stereotactic radiosurgery (SRS) for patients with asymptomatic, petroclival region meningiomas.

METHODS

This retrospective, international, multicenter study involved patients treated with SRS for an asymptomatic, petroclival region meningioma. Study endpoints included local tumor control rate, procedural complications, and the emergence of new neurological deficits.

RESULTS

There were 72 patients (22 males, mean age 59.53 years (SD ± 11.9)) with an asymptomatic meningioma located in the petroclival region who were treated with upfront SRS. Mean margin dose and maximum dose were 13.26 (SD ± 2.72) Gy and 26.14 (SD ± 6.75) Gy respectively. Median radiological and clinical follow-up periods post-SRS were 52.5 (IQR 61.75) and 47.5 months (IQR 69.75) respectively. At last follow-up, tumor control was achieved in all patients. SRS-related complications occurred in 6 (8.33%) patients, with 3 of them (4.17%) exhibiting new neurological deficits.

CONCLUSIONS

Upfront SRS for asymptomatic, petroclival region meningiomas affords excellent local tumor control and does so with a relatively low risk of SRS-related complications. SRS can be considered at diagnosis of an asymptomatic petroclival region meningioma. If active surveillance is initially chosen, SRS should be recommended when growth is noted during radiological follow-up.

Impact of the Extent of Microsurgical Resection in Sphenopetro-clival Meningiomas Trough a Multistaged Approach: A Volumetric Analysis

Objective  Sphenopetroclival meningiomas (SPCMs) represent a challenge for surgical treatment. The authors used an objective volumetric analysis to assess the effect of the grade of resection and different surgical strategies that may affect the outcome of this tumors. Methods  Over a period of 4 years, patients with SPCMs were treated using a middle versus posterior fossa approach, or a two-stage surgery combining both approaches, based on the tumor location in relation to the petrous ridge and tumor volume. Retrospectively, all cases were analyzed with regard to tumor volume, extent of resection (EOR), functional outcome, and complications. Results  Twenty-seven patients with SPCMs met the inclusion criteria, and the mean follow-up was 24.8 months. Eleven patients underwent a two-stage surgery, while 16 patients had their SPCMs resected via a single craniotomy. Mean EOR was 87.6% and gross total resection was achieved in 48% of patients. Patients with greater EOR had better functional outcomes ( r  = 0.81, p  < 0.01). Greater EOR was not accompanied by a significant increase in surgical complications. There was a trend toward lower postoperative volumes and better EOR with our two-stage approach (2.2 vs. 3.2 cm ³ , p  = 0.09; and 94.1 vs. 91.2%, p  = 0.49, respectively), without an increase in the rate of complications (18.7 vs. 18.2%, p  = 0.5). Conclusion  Staging of the surgical resection of larger tumors may lead to greater EOR, and this strategy should be considered for larger tumors.

Posterior petrosal approach for microsurgical resection of petroclival meningioma: 3-Dimensional operative video

Background:

Petroclival meningiomas are challenging lesions considering their deep location and close relationship with many vital neurovascular structures.[1-8]

Case Description:

We present the case of a 54-year-old male presenting a history of headache, dizziness, and tinnitus on the left side, associated with left facial hypoesthesia. Preoperative imaging depicted a lesion highly suggestive of a petroclival meningioma with important compression of the brainstem. Considering worsening of symptoms, size, and location of this lesion, microsurgical resection was indicated. A left posterior petrosal approach was employed with aid of neurophysiological monitoring. The patient was placed in a true lateral position and an arciform incision was done. First, the mastoidectomy was performed and then the craniotomy around encompassing both posterior and middle cranial fossae. Middle and posterior fossa dural incisions were connected through coagulation of the superior petrosal sinus. Then tentorium was all the way cut to the incisura. After that, sigmoid sinus can be mobilized posteriorly, increasing exposure of presigmoid space. The area since jugular foramen up to the supratentorial region was fully exposed, allowing safe total resection of the lesion. Postoperative imaging demonstrated complete tumor removal. Patient presented improvement of symptoms, with no new neurological deficits on follow-up.

Conclusion:

The posterior petrosal approach provided a shorter pathway and direct angle of attack to the tumor attachment, allowing successful resection.[1,6] Extensive laboratory training is essential to get familiarized with the complex anatomical relationships in that area. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Volumetric growth of residual meningioma - A systematic review

Surgical resection of meningioma leaves residual solid tumour in over 25% of patients. Selection for further treatment and follow-up strategy may benefit from knowledge of volumetric growth and factors associated with re-growth. The aim of this review was to evaluate volumetric growth and variables associated with growth in patients that underwent incomplete resection of a meningioma without the use of adjuvant radiotherapy. A systematic review was conducted in accordance with the PRISMA statement and registered a priori with PROSPERO (registration number: CRD42020177052). Six databases were searched up to May 2020. Full text articles analysing volumetric growth rates in at least 10 patients who had residual meningioma after surgery were assessed. Four single-centre, retrospective studies totalling 238 patients were included, of which 99% of meningioma were WHO grade 1. The absolute tumour growth rate ranged from 0.09 to 4.94 cm³ per year. The relative growth rate ranged from 5.11 to 14.18% per year. Varying methods of volumetric assessment and definitions of growth impeded pooled analysis. Pre-operative and residual tumour volume, and hyperintensity on T2 weighted MRI were identified as variables associated with residual meningioma growth, however this was inconsistent across studies. Risk of bias was high in all studies. Radiological regrowth occurred in 42-67% of cases. Our review identified that volumetric growth of residual meningioma is scarcely reported. Sufficiently powered studies are required to delineate volumetric growth and prognostic factors to stratify management.

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.

Does general comorbidity impact the postoperative outcomes after surgery for large and giant petroclival meningiomas?

We assessed the role of the general condition of the patient in addition to usual anatomical reasoning to improve the prediction of personalized surgical risk for patients harboring a large and giant petroclival meningiomas. Single-center, retrospective observational study including adult patients surgically treated for a large and giant petroclival meningioma between January 2002 and October 2019 in a French tertiary neurosurgical skull-base center by one Neurosurgeon. Inclusion criteria were as follows: (1) histopathologically proven meningioma; (2) larger than 3 cm in diameter; (3) located within the upper two-thirds of the clivus, the inferior petrosal sinus, or the petrous apex around the trigeminal incisura, medial to the trigeminal nerve. Clinical and radiological characteristics were gathered preoperatively including ASA score, the modified frailty index, and the Charlson comorbidity index. Post-operative severe neurological and non-neurological complications were collected. A total of 102 patients harboring a large and giant petroclival meningioma were included. The rate of postoperative death was 3.0% related to a congestive heart failure (n = 1), a surgical site hematoma (n = 1), and an ischemic stroke (n = 1). A severe neurological impairment was found in 12.8% and a severe non-neurological morbidity was found in 4.0%. The overall rate of severe morbidity and mortality was 15.7% after large and giant petroclival meningioma surgery. The presence of brainstem peri-tumoral edema (adjusted OR, 4.83 [95% CI 1.84-7.52], p = 0.028) was independently associated with a history of postoperative severe neurological morbidity. Male gender (adjusted OR, 7.42 [95% CI 1.05-49.77], p = 0.044), major cardiovascular morbidity (adjusted OR, 9.5 [95% CI 1.05-86.72], p = 0.045), and an ASA score ≥ 2 (adjusted OR, 11.09 [95% CI 1.46-92.98], p = 0.038) were independently associated with a history of postoperative severe non-neurological morbidity. A modified frailty index ≥ 1 (adjusted OR, 3.13 [95% CI 1.07-9.93], p = 0.047) and a low neurosurgical experience (adjusted OR, 5.38 [95% CI 1.38-20.97], p = 0.007) were independently associated with a history of postoperative overall morbidity and mortality. Pre-operative cranial nerve deficits (adjusted OR, 4.77 [95% CI 1.02-23.31], p = 0.024) and gross total resection (adjusted OR, 10.72 [95% CI 1.72-66.90], p = 0.022) were independently associated with postoperative new cranial nerve deficits. This study suggests to add scores assessing the patient general condition in daily practice to improve the selection of patients eligible for surgery. Collaborative international multicenter studies will be necessary to confirm these results and allow their implementation in clinical routine.

Petroclival meningiomas: update of current treatment and consensus by the EANS skull base section

BACKGROUND

The optimal management of petroclival meningiomas (PCMs) continues to be debated along with several controversies that persist.

METHODS

A task force was created by the EANS skull base section along with its members and other renowned experts in the field to generate recommendations for the management of these tumors. To achieve this, the task force reviewed in detail the literature in this field and had formal discussions within the group.

RESULTS

The constituted task force dealt with the existing definitions and classifications, pre-operative radiological investigations, management of small and asymptomatic PCMs, radiosurgery, optimal surgical strategies, multimodal treatment, decision-making, and patient's counselling.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the management of PCMs.

Differences in surgical outcome between petroclival meningioma and anterior petrous meningioma

BACKGROUND

Petroclival meningiomas (PC MNGs) and anterior petrous meningiomas (AP MNGs) have similar locations. However, these are different tumors clearly divided by the trigeminal nerve. There has never been a study on the comparison of the surgical outcomes of these two meningiomas. In this study, we compared and analyzed the surgical outcome of PC MNGs and AP MNGs.

METHODS

The charts of 85 patients diagnosed with PC MNGs of AP MNGs who underwent surgical treatment were retrospectively reviewed. And we analyzed the characteristics of 49 PC MNGs (57.6%) and compared them with those of 36 AP MNGs.

RESULTS

Preoperative brainstem edema was observed in 11 patients (22.4%) of the PC MNG group and 1 patient (2.8%) of the AP MNG group (p = 0.024). Total tumor removal was achieved in 21 patients (58.3%) of the AP MNG group, but only 17 patients (34.7%) of the PC MNG group were able to completely (p = 0.047). In addition, sixth cranial nerve palsy occurred in 17 patients (34.7%) of the PC MNG group and 4 patients (11.1%) of the AP MNG group (p = 0.025).

CONCLUSIONS

In this study, we found that PC MNGs has a worse surgical outcome than AP MNGs, because PC MNGs were difficult to completely remove and were more likely to damage abducens nerve.

Piezosurgery for safe and efficient petrous bone cutting in cerebellopontine angle and petroclival meningioma surgery

Intradural petrous bone drilling has become a widespread practice, providing extended exposure in the removal of cerebellopontine angle (CPA) or petroclival tumors. Adjacent neurovascular structures are at risk, however, when drilling is performed in this deep and narrow area. Hence, this study evaluates the use of Piezosurgery (PS) as a non-rotating tool for selective bone cutting in CPA surgery. A Piezosurgery® device was used in 36 patients who underwent microsurgery for extra-axial CPA or petroclival tumors in our Neurosurgical Department between 2013 and 2019. The clinical and radiological data were retrospectively analyzed. The use of PS was evaluated with respect to the intraoperative applicability and limitations as well as efficacy and safety of the procedure. Piezosurgical petrous bone cutting was successfully performed in the removal of meningiomas or extra-axial metastases arising from the dura of the petroclival region (21 patients) or petrous bone (15 patients). PS proved to be very helpful in the deep and narrow CPA region, considerably reducing the surgeon's distress toward bone removal in close proximity to cranial nerves and vessels in comparison to common rotating drills. The use of PS was safe without injuries to neurovascular structures. Gross total resection was achieved in 67% of petroclival and 100% of petrous bone tumors. Piezosurgery proved to be an effective and safe method for selective petrous bone cutting in CPA surgery avoiding rotating power and associated risks. This technique can particularly be recommended for bone cutting in close vicinity to critical neurovascular structures.

Analysis of Approaches in the Microsurgical Treatment of 102 Cases of Petroclival Meningioma in a Single Center

Objectives: We identified the optimal approaches for treating the diverse tumor subtypes of petroclival meningioma (PM) by analyzing the clinical benefits of various surgical approaches adopted for each subtype. Methods: Tumors in 102 PM patients from a single center who underwent surgical treatment were classified as upper clivus (UC), cavernous sinus (CS), tentorium (TE), or petrous apex (PA) types based on the attachment site of the tumor base and the displacement of the trigeminal nerve. The therapeutic effects of different surgical approaches among the subtypes were evaluated according to the patient outcomes. Results: The subtemporal (33.33%), retrosigmoid (16.67%), and Kawase approaches (50%) were used for the UC type. Simpson I/II resection was achieved in 46.66% of patients with the Kawase approach. Significant differences were found between the other two approaches (P = 0.044) and in the follow-up Karnofsky performance scale (KPS) scores (P = 0.008). The subtemporal (60%) and Kawase approaches (40%) were used for the CS type; neither approach achieved Simpson I/II resection. The retrosigmoid (25.81%) and Kawase approaches (74.19%) were used for the TE type. The Simpson I/II resection rates of the two approaches were 55.55 and 86.95%, respectively, and a significant difference was observed between them (P = 0.039). The retrosigmoid (43.75%) and Kawase approaches (56.25%) were used for the PA type. The Simpson I/II resection rates of the two approaches were 31.25 and 50%, respectively. The resection degrees of the two approaches and the KPS scores at follow-up were significantly different (P = 0.034). Conclusion: The individual microsurgical approaches adopted for the various PM tumor subtypes can provide maximal safe resection and good KPS scores. The Kawase approach is more suitable for PM, especially for UC- and PA-type PM tumors.

Petroclival Meningioma: Management Strategy and Results in 21st Century

Background

Petroclival meningioma (PCM) is considered among the most difficult tumors to be treated by microneurosurgery because of its location and its relation to critical structures. The authors report on the outcome in a series of patients with PCM treated in the new millennium with a tailored approach of gross total excision or subtotal removal and adjuvant Gamma Knife Radiosurgery (GKR) depending on the particular case.

Methods

Between 2001 and 2017, 72 consecutive PCMs were operated in a single center by the senior surgeon. Clinical presentation, operative approaches, intraoperative findings, complications, and imaging findings were retrospectively analyzed. Postoperative outcome, adjuvant Gamma knife, and follow-up findings were reviewed.

Results

The average age was 47.95 years, and female-to-male ratio was 52:20. Cavernous sinus extension was present in 21 patients. The mean duration of follow-up was 66.65 months. Gross-total resection, near-total resection (NTR), and subtotal resection (STR) resection was achieved in 30, 24, and 18 (42.8%, 34.28%, and 25%) patients, respectively, with recurrences of 10%, 33%, and 50%, respectively. Twenty-two patients (18 STR and 4 NTR) had received postoperative GKR. Only four patients had recurrences following GKR. New cranial nerve deficits were more common in patients in whom a total resection was performed. There was no mortality.

Conclusions

Gross total excision had the best recurrence free rate though with a higher morbidity. Upfront GKR is advisable in patients with residual tumor, if the preoperative temporal course had a rapid symptomatology, to reduce recurrence. Wait and watch for a small intracavernous residue and radiosurgery on growth is also a valid option as long as follow-up is not suspect. A flexible approach of individualizing the treatment protocol for a given patient goes a long way toward optimal outcome.

Ten-year follow-up after Gamma Knife radiosurgery of meningioma and review of the literature

Objectives

With regard to the generally slow growth of meningioma, it is essential to analyse clinical treatment results in a long-term perspective. The purpose of the present analysis is to provide clinical data after Gamma Knife radiosurgery of meningioma in a 10-year perspective together with a review of the current literature.

Methods

The current study is a retrospective analysis of 86 consecutive Swedish patients with meningiomas treated using Gamma Knife radiosurgery at the Karolinska Hospital Stockholm between March 1991 and May 2001. A total of 130 tumours were treated in 115 treatment sessions. The median radiological follow-up was 10 years (1.8–16.5 years), and the median clinical follow-up was 9.4 years (2.1–17.4 years).

Results

After a median follow-up period of 10 years, local tumour control was achieved in 87.8% of meningiomas (108/123 tumours). The median latency between initial treatment and local (in-field) recurrence (n = 15) was 5.8 years (1.9–11.5). Recurrences adjacent but outside the initial radiation field occurred in 15.1% of patients (13/86) at a median of 7.5 years (1.3–15.7). New meningiomas were seen in 10.5% after a median of 5.4 years (0.9–10.8). In 72% of patients, no further treatment was required, 17.4% (15/86) underwent a second Gamma Knife treatment, 4.7% (4/86) required later open surgery and 5.8% (5/86) required both secondary treatments. Eighty-six percent of patients were neurologically unchanged or improved. A significantly lower rate of local (in-field) recurrences was seen in meningiomas treated with a prescription dose of > 13.4 Gy (7.1% vs. 24%, p = 0.02).

Conclusions

The current retrospective analysis provides a 10-year follow-up and comprises one of the longest available follow-up studies of radiosurgically treated meningiomas. The current series documents a persistent high local tumour control after Gamma Knife treatment, while providing an estimation of a necessary minimum dose for long-term tumour control in meningiomas. The study confirms the validity of previous short-term data in a long-term perspective.

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.

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.

Petroclival meningiomas and the petrosal approach

As with other meningiomas, the goal of petroclival meningioma treatment should be curative total removal by achieving a Simpson I resection of the tumor, dura, and bone. Petroclival meningiomas particularly pose a great technical challenge because of their deep location and intimate relation with vital neurovascular structures. They require adequate exposure and trajectory to achieve total removal while minimizing the manipulation and risk to critical neurovascular structures, such as the vertebrobasilar system, the brainstem, and the cranial nerves. Here, we describe the indications and technical nuances of the posterior and combined posterior-anterior petrosal approaches for petroclival meningiomas.

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.

Found at Old Age and Continuously Growing WHO Grade II Fourth Ventricle Ependymoma: A Case Report

A 74-year-old woman presented with a month-long nausea and vomiting, then she could not take a meal. She had found an asymptomatic 4th ventricular mass 6 year ago as a preoperative work-up for ovarian cancer. And during the yearly follow-up, the mass had grown continuously over 6 years, and caused symptoms in the seventh year. MRI revealed a large ovoid extra-axial mass in the fourth ventricle compressing adjacent medulla and cerebellum. Surgery achieved near total resection since the tumor tightly adhered to the brain stem of 4th ventricle floor. The histological diagnosis was ependymoma (WHO grade II). She transferred rehabilitation facility for mild gait disturbance, hoarseness and swallowing difficulty. Fourth ventricle ependymoma in the elderly is extremely rare and the growth rate has not been reported. Here, we present a rare care of 4th ventricle ependymoma found asymptomatic at elderly but continuously grow to cause local pressure symptoms.

Tumor Progression Following Petroclival Meningioma Subtotal Resection: A Volumetric Study

BACKGROUND

One study has investigated postoperative growth rates following subtotal resection of petroclival meningiomas utilizing linear measurements, which are insensitive to the multidimensional complex growth of meningiomas, to estimate tumor volume.

OBJECTIVE

To describe petroclival meningioma growth patterns following less-than-complete resection utilizing volumetric analysis and to identify variables associated with tumor progression.

METHODS

Patients with surgically resected WHO grade I petroclival meningiomas were retrospectively reviewed (1999-2015). Image analysis software was utilized to perform volumetric analyses of tumor size and growth on serial MRI studies. The impact of preoperative and postoperative variables on tumor growth after subtotal resection was analyzed. An increase in tumor volume of at least 20% was defined as "tumor growth."

RESULTS

Twenty-three patients had immediate preoperative and serial postoperative MRI studies available for review. The mean preoperative tumor volume was 20.9 cm3 (range 0.4-54.6). The mean extent of resection was 75.5% (range 31.5%-100.0%). At a mean follow-up of 24.8 mo, 12 tumors (66.7%) exhibited radiological tumor growth, while 6 tumors did not change in size. The median annual volumetric growth rate was 2.82 cm3/yr (range -0.34 to 10.1). Extent of resection and immediate postoperative tumor volume were significantly correlated with the annual volumetric growth rate following resection. At last follow-up, 3 (13%) patients required further intervention.

CONCLUSION

The majority of petroclival meningiomas exhibit growth following subtotal resection. Extent of resection is strongly associated with risk for disease progression following surgery.

Nonvestibular Schwannoma Tumors in the Cerebellopontine Angle: A Single-Surgeon Experience

Background:

The most common cerebellopontine angle (CPA) tumor is a vestibular schwannoma. Schwannomas account for 8.5% of all intracranial tumors and more than 90% of the tumors originate from the eighth cranial nerve, but one in five CPA tumors are not vestibular schwannoma. These tumors may have different manifestations and require different management strategies.

Methods:

We report 224 consecutive NVCPAT operated in the Department of Neurosurgery, P.D. Hinduja National Hospital and Medical Research Centre, Mumbai, by the senior author between 2001 and 2014 and discuss the different approaches and outcomes in NVCPAT.

Results:

The age range was 20–60 years and there were 129 females and 95 male patients. The clinical material consisted of 81 cases of meningioma (36.1%), 44 cases of epidermoid (19.64%), 34 cases of trigeminal schwannoma (15.17%), 26 cases of jugular foramen schwannoma (11.60%), and 39 cases of other tumors (17.41%). In nonvestibular schwannoma (NVS), symptoms and signs from cranial nerve VIII are less frequent and other cranial nerves and cerebellar symptoms and signs predominate.

Conclusion:

Symptoms and signs are different in NVCPAT from those found in patients with vestibular schwannoma. Hearing loss is not the predominant symptoms. Cerebellar signs and trigeminal dysfunction are more common. The most common approach used in the current series was retrosigmoid craniotomy. Gamma knife radiosurgery was a useful adjunct in a subset of these patients.

Prognostic factors for progression in atypical meningioma

OBJECTIVE

The optimal adjuvant management for atypical meningiomas remains controversial. The aim of this study was to review long-term outcomes to identify potential prognostic factors for disease progression.

METHODS

From August 1992 to August 2013, 70 patients with atypical meningioma were treated at the authors’ institution. Pathology revision was performed based on WHO 2007 criteria. Patients with multiple tumors, neurofibromatosis Type 2, or inadequate imaging follow-up were not eligible. The authors performed pre- and postoperative serial measurements of tumor volume from MRI. Age, sex, tumor location, bone involvement, brain invasion, mitotic figures, preoperative disease volume, extent of resection, tumor growth rates, use of adjuvant postoperative radiation therapy (PORT), and residual tumor volume at the time of radiation therapy (RT) were assessed by univariate and multivariate analysis to determine their potential impact on disease progression.

RESULTS

Forty patients (57%) underwent gross-total resection (GTR) and 30 (43%) underwent subtotal resection (STR). PORT was delivered to 12 patients (30%) with a GTR and in only 4 (13%) with an STR. The 5-year progression-free survival (PFS) rate for patients in the GTR group with or without PORT was 100% and 54.1%, respectively (p = 0.0058). PFS for patients in the STR group with or without PORT was 75% and 0%, respectively (p = 0.0026). On multivariate analysis, STR and PORT were the only independent significant prognostic factors for disease progression with hazard ratios of 5.4873 (95% CI 2.19–13.72, p = 0.0003) and 0.0464 (95% CI 0.0059–0.364, p = 0.0035), respectively. Based on Youden’s index statistic, a cutoff residual tumor volume of more than 8.76 cm3 at the time of RT was associated with worse PFS (13.6% vs 56%, p = 0.0079). Before receiving RT, the median relative and absolute growth rates and tumor doubling time for patients were 124.2%/year, 4.8 cm3/year, and 1.67 years, respectively. These indices changed after RT to 0.245%/year, −0.09 cm3/year, and −0.005 year, respectively (p < 0.05).

CONCLUSIONS

In atypical meningioma, the use of PORT is associated with improved PFS even in patients who undergo GTR. Patients with residual tumor volume larger than 8.76 cm3 have an increased risk of disease progression and should be considered for early RT.

Extended Retrosigmoid Approach for Cerebellopontine Angle Meningiomas: Operative Technique and Results-A Series of 28 Patients

Background  The purpose of this article is to describe our approach, surgical strategies, and results for resection of meningiomas located at cerebellopontine angle (CPA). Methods  We retrospectively identified 28 patients with CPA meningiomas operated by the extended retrosigmoid approach. This approach incorporates a generous mastoidectomy and the sigmoid sinus exposure. Results  The mean age was 33.8 years, with a follow-up of 12.5 years. Gross total removal (GTR) was achieved in 22 (78.5%) patients with low surgical mortality, acceptable morbidity, and recurrence rate of 7.1% (2 patients). Conclusion  The extended retrosigmoid approach enhances the exposure of the CPA and posterior fossa cisterns and increases the surgical angle of maneuverability. This approach provides adequate access even to extensive CPA meningiomas, enabling, in most of cases, GTR to be safe and effective. The extended retrosigmoid approach used in this group of patients is an alternative to more extensive cranial base approaches.

Volumetric tumor growth rates of meningiomas involving the intracranial venous sinuses

OBJECT

There is currently no consensus as to whether meningiomas located inside the venous sinuses should be aggressively or conservatively treated. The goals of this study were to identify how sinus-invading meningiomas grow, report and compare growth rates of tumor components inside and outside the different venous sinuses, identify risk factors associated with increased tumor growth, and determine the effects of the extent of tumor resection on recurrence for meningiomas that invade the dural venous sinuses.

METHODS

Adult patients who underwent primary, non-biopsy resection of a WHO grade 1 meningioma invading the dural venous sinuses at a tertiary care institution between 2007 and 2015 were retrospectively reviewed. Rates of tumor growth were fit to several growth models to evaluate the most accurate model. Cohen's d analysis was used to identify associations with increased growth of tumor in the venous sinuses. Logistic regression was used to compare extent of resection with recurrence.

RESULTS

Of the 68 patients included in the study, 34 patients had postoperative residual tumors in the venous sinuses that were measured over time. The growth model that best fit the growth of intrasinus meningiomas was the Gompertzian growth model (r² = 0.93). The annual growth rate of meningiomas inside the sinuses was 7.3%, compared to extrasinus tumors with 13.6% growth per year. The only factor significantly associated with increased tumor growth in sinuses was preoperative embolization (effect sizes (ES) [95% CI], 1.874 [7.633-46.735], p = 0.008).

CONCLUSIONS

This study shows that meningiomas involving the venous sinuses have a Gompertzian-type growth with early exponential growth followed by a slower growth rate that plateaus when they reach a certain size. Overall, the growth rate of the intrasinus portion is low (7.3%), which is half of the reported growth rates for other studies involving primarily extrasinus tumors.

Skull base versus non-skull base meningioma surgery in the elderly

To compare outcomes after surgery for skull base meningiomas (SBMs) with non-skull base meningiomas (NSBMs) in the elderly. Overall, 128 consecutive patients ≥ 70 years of age with intracranial SBMs operated between 1990 and 2010 were compared to 193 consecutive patients ≥ 70 years of age with NSBMs operated within the same time period. Median age at surgery was 75.0 years (mean 75.7, range 70.0-92.4). Follow-up was complete with median 4.7 years (mean 5.5, range 0-19). The female-to-male ratio was 2.8 for SBMs and 1.3 for NSBMs (p < 0.005). The groups had similar preoperative KPS (median 80, range 20-100), but SBMs presented significantly more frequently with raised ICP (RR = 2.2, p < 0.005) and less frequently with seizures (RR = 0.6, p < 0.05). WHO I was significantly more frequent in SBMs (p < 0.005). Gross-total resection (GTR) was less frequent in SBMs (63 vs 82%) (RR = 2.1, p < 0.0001). SBMs were similar to NSBMs with respect to neurological outcome at 6-12 months, reoperations for hematomas, postoperative infections, and 30-day mortality. Retreatment rates and time to retreatments were also similar. There were no differences between the two groups with respect to risk of retreatment and overall survival (OS) at 5, 10, 15, and 20 years. In elderly patients with SBMs selected to surgical treatment, the risks of surgery, risk of retreatment, and OS were similar to NBSMs. Therefore, surgery for SBMs may be considered as safe as NSBMs in the elderly population.

Fractionated Gamma Knife Radiosurgery as Initial Treatment for Large Skull Base Meningioma

We present our experience on the hypofractionated Gamma Knife radiosurgery (FGKS) for large skull base meningioma as an initial treatment. We retrospectively reviewed 23 patients with large skull base meningioma ≥10 cm³ who underwent FGKS as the initial treatment option. The mean volume of tumors prior to radiosurgery was 21.2±15.63 cm³ (range, 10.09~71.42). The median total margin dose and marginal dose per fraction were 18 Gy (range, 15~20) and 6 Gy (range, 5~6), respectively. Patients underwent three or four fractionations in consecutive days with the same Leksell® frame. The mean follow-up duration was 38 months (range, 17~78). There was no mortality. At the last follow-up, the tumor volume was stationary in 15 patients (65.2%) and had decreased in 8 patients (34.8%). Six patients who had cranial neuropathy at the time of FGKS showed improvement at the last clinical follow-up. Following FGKS, 4 patients (17%) had new cranial neuropathy. The trigeminal neuropathy was the most common and all were transient. The mean Karnofsky Performance Status score at pre-FGKS and the last clinical follow-up was 97.0±10.4 points (median, 100) and 98.6±6.9 (median, 100) points, respectively. FGKS has showed satisfactory tumor control with functional preservation for large skull base meningiomas. Further prospective studies of large cohorts with long term follow-up are required to clarify the efficacy in the tumor control and functional outcome as well as radiation toxicity.

Surgical outcomes after reoperation for recurrent skull base meningiomas

OBJECTIVE

Skull base meningiomas are surgically challenging tumors due to the intricate skull base anatomy and the proximity of cranial nerves and critical cerebral vasculature. Many studies have reported outcomes after primary resection of skull base meningiomas; however, little is known about outcomes after reoperation for recurrent skull base meningiomas. Since reoperation is one treatment option for patients with recurrent meningioma, the authors sought to define the risk profile for reoperation of skull base meningiomas.

METHODS

A retrospective review of 2120 patients who underwent resection of meningiomas between 1985 and 2016 was conducted. Clinical information was extracted from the medical records, radiology data, and pathology data. All records of patients with recurrent skull base meningiomas were reviewed. Demographic data, presenting symptoms, surgical management, outcomes, and complications data were collected. Kaplan-Meier analysis was used to evaluate survival after reoperation. Logistic regression was used to evaluate for risk factors associated with complications.

RESULTS

Seventy-eight patients underwent 100 reoperations for recurrent skull base meningiomas. Seventeen patients had 2 reoperations, 3 had 3 reoperations, and 2 had 4 or more reoperations. The median age at diagnosis was 52 years, and 64% of patients were female. The median follow-up was 8.5 years. Presenting symptoms included cranial neuropathy, headache, seizure, proptosis, and weakness. The median time from initial resection to first reoperation was 4.4 years and 4.1 years from first to second reoperation. Seventy-two percent of tumors were WHO grade I, 22% were WHO grade II, and 6% were WHO grade III. The sphenoid wing was the most common location (31%), followed by cerebellopontine angle (14%), cavernous sinus (13%), olfactory groove (12%), tuberculum sellae (12%), and middle fossa floor (5%). Forty-four (54%) tumors were ≥ 3 cm in maximum diameter at the time of the first reoperation. In 100 reoperations, 60 complications occurred in 30 cases. Twenty of the 60 complications required surgical intervention (33%). Complications included hydrocephalus (12), CSF leak/pseudomeningocele (11), wound infection (9), postoperative hematoma (4), venous infarction (1), and pneumocephalus (1). Postoperative neurological deficits included new or worsened cranial nerve deficits (10) and hemiparesis (3). There were no perioperative deaths in this series. On multivariate analysis, posterior fossa location was significantly associated with complications (OR 3.45, p = 0.0472). The 1-, 2-, 5-, and 10-year overall survival rates according to Kaplan-Meier analysis after the first reoperation were 94%, 92%, 88%, and 76%, respectively. The median survival after the first reoperation was 17 years.

CONCLUSIONS

Recurrent skull base meningiomas are surgically challenging tumors, and reoperation is associated with high morbidity and complication rates. Despite these cautionary data, repeat resection of recurrent skull base meningiomas in appropriately selected patients provides excellent long-term survival.

Treatment of Lateral Skull Base and Posterior Cranial Fossa Lesions Utilizing the Extended Middle Cranial Fossa Approach

OBJECTIVE

Define the indications and outcomes for subjects undergoing treatment utilizing the extended middle cranial fossa approach (EMCF).

STUDY DESIGN

Retrospective records review.

SETTING

University-based tertiary referral center.

PATIENTS

Subjects undergoing treatment of posterior cranial fossa (PCF) lesions.

INTERVENTION(S)

EMCF exposure and treatment of the indicating PCF lesion.

MAIN OUTCOME MEASURE(S)

Demographic, audiometric, and cranial nerve functioning variables were assessed.

RESULTS

Thirty-five subjects who underwent an EMCF exposure were identified over a 12-year period. The most common indication was meningioma (18; 51%) followed by schwannomas (six, 17%), and vascular lesions (five, 14%). Preoperative cranial nerve complaints were common (32, 94%) as were objective cranial nerve abnormalities on physical examination (21; 60%). Preoperative audiometric data from subjects with hearing demonstrated good functioning including pure-tone average (PTA) (21.7 ± 15.6 dB HL) and word understanding scores (95.1 ± 7.4%). Most (34, 97%) subjects had intact facial nerve function. The average length of stay was 11.6 days (median = 9). Cranial neuropathies were common postoperatively with 27 (79%) subjects demonstrating some objective cranial nerve dysfunction, the most common of which was trigeminal nerve hypesthesia (21, 61.7%). Subjects with identifiable pre- and postoperative audiometric data and preoperative hearing demonstrated small declines in the four-tone average (16.2 dB) and word recognition scores (22.4%). Two subjects (6%) had new profound hearing loss postoperatively.

CONCLUSIONS

The EMCF approach can provide safe and effective exposure of the anterior PCF.

Petroclival Meningiomas: Factors Determining the Choice of Approach

Objectives  To review a surgical series of petroclival meningiomas and the factors considered in the choice of approach. Design  Retrospective review. Setting  The study was conducted in a university hospital in southern Brazil. Participants  Twenty-two patients with petroclival meningioma originating from the upper two-thirds of the clivus medial to the fifth cranial nerve. Main Outcome Measures  Gross-total resection, mortality, major morbidity, new cranial nerve deficits and tumor progression or recurrence. Results  Retrosigmoid approach was used in tumors <3 cm and in those at or below the internal auditory meatus. Posterior petrosectomy was performed for tumors extending into the middle fossa. Gross-total resection was performed in 11 patients (50%). The mean follow-up time was 32 months (6-75 months). There were four cases of tumor progression or recurrence, which were treated with radiosurgery. Conclusions  Resection of petroclival meningiomas remains challenging. In most cases, the retrosigmoid approach was sufficient, without affecting the degree of tumor resection. Petrosal approaches were reserved for patients with tumor extension into the middle fossa.

Recurred Intracranial Meningioma: A Retrospective Analysis for Treatment Outcome and Prognostic Factor

Background

In this study, we aimed to compare repeated resection and radiation treatment, such as Gamma knife radiosurgery (GKRS) or conventional radiotherapy (RT), and investigate the factors influencing treatment outcome, including overall survival (OS), progression-free survival (PFS), and complication rates.

Methods

We retrospectively reviewed 67 cases of recurred intracranial meningiomas (repeated resection: 36 cases, radiation treatment: 31 cases) with 56 months of the median follow-up duration (range, 13–294 months).

Results

The incidence of death rate was 29.9% over follow-up period after treatment for recurred meningiomas (20/67). As independent predictable factors for OS, benign pathology [hazard ratio (HR) 0.132, 95% confidence interval (CI) 0.048–0.362, p<0.001] and tumor size <3 cm (HR 0.167, 95% CI 0.061–0.452, p<0.001) were significantly associated with a longer OS. The incidence of progression rate was 23.9% (16/67). Only treatment modality was important for PFS as an independent predictable factor (GKRS/RT vs. open resection; HR 0.117, 95% CI 0.027–0.518, p<0.005). The complication rate was 14.9% in our study (10/67). Larger tumor size (≥3 cm, HR 0.060, 95% CI 0.007–0.509, p=0.010) was significant as an independent prognostic factor for development of complications. Although treatment modality was not included for multivariate analysis, it should be considered as a predictable factor for complications (p=0.001 in univariate analysis).

Conclusion

The role of repeated resection is questionable for recurred intracranial meningiomas, considering high progression and complication rates. Frequent and regular imaging follow-up is required to detect recurred tumor sized as small as possible, and radiation treatment can be a preferred treatment.

Volumetric growth rates of meningioma and its correlation with histological diagnosis and clinical outcome: a systematic review

INTRODUCTION

Tumour growth has been used to successfully predict progression-free survival in low-grade glioma. This systematic review sought to establish the evidence base regarding the correlation of volumetric growth rates with histological diagnosis and potential to predict clinical outcome in patients with meningioma.

METHODS

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Databases were searched for full text English articles analysing volumetric growth rates in patients with a meningioma.

RESULTS

Four retrospective cohort studies were accepted, demonstrating limited evidence of significantly different tumour doubling rates and shapes of growth curves between benign and atypical meningiomas. Heterogeneity of patient characteristics and timing of volumetric assessment, both pre- and post-operatively, limited pooled analysis of the data. No studies performed statistical analysis to demonstrate the clinical utility of growth rates in predicting clinical outcome.

CONCLUSION

This systematic review provides limited evidence in support of the use of volumetric growth rates in meningioma to predict histological diagnosis and clinical outcome to guide future monitoring and treatment.

Outcomes of Endonasal and Lateral Approaches to Petroclival Meningiomas

OBJECTIVE

Transpetrosal approaches for the treatment of petroclival meningiomas are often associated with substantial morbidity and long recovery. With the goal of early clinical improvement, we have used less invasive surgical approaches for petroclival meningiomas.

METHODS

We retrospectively reviewed 32 patients with petroclival meningiomas. Eleven patients (34.4%) were managed with lateral approaches (retrosigmoid or far lateral approach), 17 (53.1%) with anterior midline approaches (endoscopic endonasal approach [EEA]), and 4 (12.5%) with a combination.

RESULTS

The average Karnofsky Performance Score (KPS) at presentation was 73.8. The average postoperative KPS improved to 87.9 (P < 0.001) during short-term follow-up of 14 months (range, 1-42) and was significantly higher in primary tumors (P = 0.013), tumors <4 cm (P = 0.039), and tumors without vascular encasement (P = 0.002) but remained significant regardless of age, tumor size, or vascular encasement. The greatest benefit occurred with primary tumors, in young patients and in those who underwent nontotal resection (P < 0.001). EEA had a significantly greater potential for improved KPS (P = 0.002). Gross (n = 6) or near total (n = 9) resection was achieved in 15 of 32 cases (47%). Complications included new cranial nerve palsies affecting mainly the abducens nerve (18.7%). New lower cranial nerve palsies occurred in only 1 case (3.1%). Other complications included postoperative hydrocephalus (15.6%) and cerebrospinal fluid leak (28.1%). One patient died in the perioperative period (3.1%).

CONCLUSIONS

In the short-term, less aggressive cranial base approaches, including retrosigmoid exposures and the recently introduced EEA, are effective alternatives to transpetrosal approaches for debulking petroclival meningiomas with significant early clinical improvement and limited major surgical complications.

Petroclival meningiomas: Remaining controversies in light of minimally invasive approaches

Surgical resection of petroclival meningiomas remains challenging due to their deep location and relationship to vital neurovascular structures. Although the natural history of these tumors involves a slow course, the incidence of cranial nerve deficits and the extent of tumor resection vary widely in the literature. Some reviews on this topic have been conducted, but data remain fragmentary and based on retrospective case series, which hinders attempts at meta-analysis. Within this context, research into the use of minimally invasive approaches, including in neuroendoscopy, continues to emerge. The objective of this narrative review is to analyze the available literature on the surgical treatment of petroclival meningiomas, with a focus on attempts at endoscopy-assisted resection.

EANO guidelines for the diagnosis and treatment of meningiomas

Although meningiomas are the most common intracranial tumours, the level of evidence to provide recommendations for the diagnosis and treatment of meningiomas is low compared with other tumours such as high-grade gliomas. The meningioma task force of the European Association of Neuro-Oncology (EANO) assessed the scientific literature and composed a framework of the best possible evidence-based recommendations for health professionals. The provisional diagnosis of meningioma is mainly made by MRI. Definitive diagnosis, including histological classification, grading, and molecular profiling, requires a surgical procedure to obtain tumour tissue. Therefore, in many elderly patients, observation is the best therapeutic option. If therapy is deemed necessary, the standard treatment is gross total surgical resection including the involved dura. As an alternative, radiosurgery can be done for small tumours, or fractionated radiotherapy in large or previously treated tumours. Treatment concepts combining surgery and radiosurgery or fractionated radiotherapy, which enable treatment of the complete tumour volume with low morbidity, are being developed. Pharmacotherapy for meningiomas has remained largely experimental. However, antiangiogenic drugs, peptide receptor radionuclide therapy, and targeted agents are promising candidates for future pharmacological approaches to treat refractory meningiomas across all WHO grades.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Individualized Surgical Approach Planning for Petroclival Tumors Using a 3D Printer

Objectives To determine the utility of three-dimensional (3D) printed models in individualized petroclival tumor resection planning by measuring the fidelity of printed anatomical structures and comparing tumor exposure afforded by different approaches. Design Case series and review of the literature. Setting Tertiary care center. Participants Three patients with petroclival lesions. Main Outcome Measures Subjective opinion of access by neuro-otologists and neurosurgeons as well as surface area of tumor exposure. Results Surgeons found the 3D models of each patient's skull and tumor useful for preoperative planning. Limitations of individual surgical approaches not identified through preoperative imaging were apparent after 3D models were evaluated. Significant variability in exposure was noted between models for similar or identical approaches. A notable drawback is that our printing process did not replicate mastoid air cells. Conclusions We found that 3D modeling is useful for individualized preoperative planning for approaching petroclival tumors. Our printing techniques did produce authentic replicas of the tumors in relation to bony structures.