Treatment Strategy for Petroclival Meningiomas Based on a Proposed Classification in a Study of 168 Cases

Surgical Strategy for Petroclival Meningioma-Related Trigeminal Neuralgia: The Role of Porus Trigeminus Opening

OBJECTIVE

Petroclival meningiomas invade Meckel's cave through the porus trigeminus, leading to secondary trigeminal neuralgia. Microsurgery and stereotactic radiosurgery (SRS) are the typical treatment options. This study investigated symptom control, outcomes, and surgical strategies for PC meningioma-induced TN.

METHODS

We retrospectively analyzed 28 TN patients with PC meningiomas who underwent microsurgical nerve decompression between January 2021 and February 2023. In all patients undergoing a transpetrosal approach, the porus trigeminus was opened to enable the removal of the entire tumor within Meckel's cave. Clinical outcomes were assessed using the Barrow Neurologic Institute (BNI) pain intensity scale. Risk factors for poor TN outcomes and poor facial numbness were analyzed.

RESULTS

Among 28 patients, 21 (75%) underwent the transpetrosal approach, 5 (17.9%) underwent the retrosigmoid approach, and 2 (7.1%) underwent the Dolenc approach. Following microsurgery, 23 patients (82.1%) experienced TN relief without further medication (BNI I or II). TN recurrence occurred in 2 patients (7.1%), and 3 patients (10.7%) did not achieve TN relief. Cavernous sinus invasion was significantly correlated with poor TN outcomes (P = 0.047). A history of previous SRS (P = 0.011) and upper clivus type tumor (P = 0.018) were significantly associated with poor facial numbness.

CONCLUSIONS

Microsurgical nerve decompression is effective in improving BNI scores in patients with TN associated with PC meningiomas. Considering the results of our study, the opening of the porus trigeminus can be considered as a suggested procedure in the treatment of PC meningiomas, especially in cases accompanied by TN.

The Evolution of Anterior Transpetrosal Approach for the Treatment of Petroclival Meningiomas: A Single-Center 128-Case Experience

BACKGROUND

The profound understanding of anterior transpetrosal approach (ATPA) is increasingly used to treat petroclival meningiomas (PCMs). We introduce the evolution of ATPA and the outcomes of PCMs treatment.

METHODS

Between January 2013 and December 2019, 128 patients with PCMs underwent surgery. According to tumor extension, we classified the 128 patients into 5 types (I-V), introduced key technologies of ATPA into different types for the first time, and achieved a supreme surgical technology. Clinical data, radiological findings, surgical treatments, complications, and patient outcomes were retrospectively analyzed.

RESULTS

A total of 22 (17.2%), 44 (34.4%), 25 (19.5%), 29 (22.7%), and 8 (6.3%) patients had type I, II, III, IV, and V disease, respectively. Tumors were gross totally removed (Simpson I and II) in 100 patients (78.1%), subtotally removed (Simpson III) in 20 patients (15.6%), and partially removed (Simpson IV) in 8 patients (6.3%). The progression or recurrence rates were 5% (5/100) for gross totally removed, 22.3% (6/20) for subtotally removed, and 62.5% (5/8; 1 died) for partially removed. According to the Karnofsky Performance Scale and Glasgow Outcome Scale, 108 patients had good recovery (84.4%, 108/128) and 115 were independent (89.8%, 115/128) at the end of follow-up.

CONCLUSIONS

Because some key technologies were used in ATPA, the application of ATPA was extended, and greater tumor resection and nerve function protection could be achieved in the treatment of PCMs.

Long-term Experience of LINAC Single-Dose Radiosurgery for Skull Base Meningiomas: A Retrospective Single-Center Study of 241 Cases

BACKGROUND AND OBJECTIVES

Stereotactic radiosurgery (SRS) is increasingly applied to treat meningiomas, attributable to their increased incidence in older individuals at greater surgical risk. To evaluate the effectiveness of treatment with linear accelerator (LINAC)-based stereotactic radiosurgery in skull base meningiomas as either primary treatment or postresection adjuvant therapy.

METHODS

This study included 241 patients diagnosed with skull base meningiomas treated by single-dose SRS, with a median age of 59 years. SRS was primary treatment in 68.1% (n = 164) and adjuvant treatment in 31.9% (n = 77), using LINAC (Varian 600, 6 MeV). The median tumor volume was 3.2 cm 3 , and the median coverage dose was 14 Gy. Bivariate and multivariate analyses were performed to determine predictive factors for tumor progression, clinical deterioration, and complications. Kaplan-Meier analysis was used for survival analysis.

RESULTS

After the median follow-up of 102 months, the tumor control rate was 91.2% (n = 220). Progression-free survival rates were 97.07%, 90.1%, and 85.7% at 5, 10, and 14 years, respectively. Clinical improvement was observed in 56 patients (23.2%). In multivariate analysis, previous surgery (hazard ratio 3.8 [95%CI 1.136-12.71], P = .030) and selectivity (hazard ratio .21 [95%CI 0.066-0.677], P = .009) were associated with tumor progression and increased maximum dose (odds ratio [OR] 4.19 [95% CI 1.287-13.653], P = .017) with clinical deterioration. The permanent adverse radiation effect rate was 6.2% (n = 15) and associated with maximum brainstem dose >12.5 Gy (OR 3.36 [95% CI .866-13.03], P = .08) and cerebellopontine angle localization (OR 3.93 [95% CI 1.29-11.98], P = .016).

CONCLUSION

Treatment of skull base meningiomas with single-dose SRS using LINAC is effective over the long term. Superior tumor control is obtained in patients without previous surgery. Adverse effects are related to localization in the cerebellopontine angle, and maximum brainstem radiation dose was >12.5 Gy.

Combined retrosigmoid and middle fossa approach for a small, superiorly located petroclival meningioma: how I do it

BACKGROUND

Petroclival meningiomas pose significant surgical challenges because of their deep location and complex surrounding neurovasculature. The use of multiple surgical approaches can optimize safe tumor removal from multiple anatomic compartments.

METHOD

We describe a patient with a growing superior petroclival meningioma centered at the posterior clinoid with extension into Meckel's cave that was successfully removed with a combined retrosigmoid and subtemporal middle fossa approach. This strategy avoided the need for anterior petrous bone drilling and tentorial splitting.

CONCLUSION

A combined retrosigmoid and subtemporal middle fossa approach can provide safe access to tumors spanning the supra- and infratentorial compartments.

Health-Related Quality of Life Outcomes in Meningioma Patients Based upon Tumor Location and Treatment Modality: A Systematic Review and Meta-Analysis

Patients with meningiomas may have reduced health-related quality of life (HRQoL) due to postoperative neurological deficits, cognitive dysfunction, and psychosocial burden. Although advances in surgery and radiotherapy have improved progression-free survival rates, there is limited evidence regarding treatment outcomes on HRQoL. This review examines HRQoL outcomes based on tumor location and treatment modality. A systematic search in PubMed yielded 28 studies with 3167 patients. The mean age was 54.27 years and most patients were female (70.8%). Approximately 78% of meningiomas were located in the skull base (10.8% anterior, 23.3% middle, and 39.7% posterior fossae). Treatment modalities included craniotomy (73.6%), radiotherapy (11.4%), and endoscopic endonasal approach (EEA) (4.0%). The Karnofsky Performance Scale (KPS) was the most commonly utilized HRQoL instrument (27%). Preoperative KPS scores > 80 were associated with increased occurrence of postoperative neurological deficits. A significant difference was found between pre- and post-operative KPS scores for anterior/middle skull base meningiomas (SBMs) in comparison to posterior (SBMs) when treated with craniotomy. Post-craniotomy SF-36 scores were lower for posterior SBMs in comparison to those in the anterior and middle fossae. Risk factors for poor neurological outcomes include a high preoperative KPS score and patients with posterior SBMs may experience a greater burden in HRQoL.

Surgical morbidity of the extradural anterior petrosal approach: the Lariboisière experience

OBJECTIVE

Concerns about the approach-related morbidity of the extradural anterior petrosal approach (EAPA) have been raised, especially regarding temporal lobe and venous injuries, hearing impairment, facial nerve palsy, cerebrospinal fluid fistula, and seizures. There is lack in the literature of studies with detailed analysis of surgical complications. The authors have presented a large series of patients who were treated with EAPA, focusing on complications and their avoidance.

METHODS

The authors carried out a retrospective review of patients who underwent EAPA at their institution between 2012 and 2021. They collected preoperative clinical characteristics, operative reports, operative videos, findings on neuroimaging, histological diagnosis, postoperative course, and clinical status at last follow-up. For pathologies without petrous bone invasion, the amount of petrous apex drilling was calculated and classified as low (< 70% of the volume) or high (≥ 70%). Complications were dichotomized as approach related and resection related.

RESULTS

This study included 49 patients: 26 with meningiomas, 10 brainstem cavernomas, 4 chondrosarcomas, 4 chordomas, 2 schwannomas, 1 epidermoid cyst, 1 cholesterol granuloma, and 1 osteoblastoma. The most common approach-related complications were temporal lobe injury (6.1% of patients), seizures (6.1%), pseudomeningocele (6.1%), hearing impairment (4.1%), and dry eye (4.1%). Approach-related complications occurred most commonly in patients with a meningioma (p = 0.02) and Meckel's cave invasion (p = 0.02). Gross-total or near-total resection was correlated with a higher rate of tumor resection-related complications (p = 0.02) but not approach-related complications (p = 0.76). Inferior, lateral, and superior tumoral extension were not correlated with a higher rate of tumor resection-related complications. No correlation was found between high amount of petrous bone drilling and approach- or resection-related complications.

CONCLUSIONS

EAPA is a challenging approach that deals with critical neurovascular structures and demands specific skills to be safely performed. Contrary to general belief, its approach-related morbidity seems to be acceptable at dedicated skull base centers. Morbidity can be lowered with careful examination of the preoperative neuroradiological workup, appropriate patient selection, and attention to technical details.

Treatment Strategies and Current Results of Petroclival Meningiomas

Petroclival meningiomas (PCMs) are complex skull-base tumors that continue to pose a formidable surgical challenge to neurosurgeons because of their deep-seated location/intimate relationship with the brainstem and neurovascular structures. The advent of stereotactic radiosurgery (SRS), along with the shifting of management goals from complete radiological cure to maximal preservation of the patient's quality of life (QOL), has further cluttered the topic of "optimal management" in PCMs. Not all patients with PCM need treatment ("watchful waiting"). However, many who reach the neurosurgeons with a symptomatic disease need surgery. The goal of the surgery in PCMs is a GTR, yet this can be achieved in only less than half of the patients with acceptable morbidity. The remainder of the patients are better treated by STR followed by SRS for residual tumor control or close follow-up. A small subset of patients with PCM may be best treated by primary SRS. In this chapter, we have tried to summarize the scientific evidence pertaining to the management of PCMs (including the senior author's series), particularly those regarding the available treatment strategies and current outcomes, and discuss the decision-making process to formulate an "optimal management" plan for individual PCMs.

Surgical results of 158 petroclival meningiomas with special focus on standard craniotomies

Objective

The goal of this retrospective study is the evaluation of risk factors for postoperative neurological deficits after petroclival meningioma (PCM) surgery with special focus on standard craniotomies.

Materials and methods

One-hundred-fifty-eight patients were included in the study, of which 133 patients suffered from primary and 25 from recurrent PCM. All patients were operated on and evaluated concerning age, tumor size, histology, pre- and postoperative cranial nerve (CN) deficits, morbidity, mortality, and surgical complications. Tumor-specific features—e.g., consistency, surface, arachnoid cleavage, and location—were set in a four-grade classification system that was used to evaluate the risk of CN deficits and tumor resectability.

Results

After primary tumor resection, new CN deficits occurred in 27.3% of patients. Preoperative ataxia improved in 25%, whereas 10% developed new ataxia. Gross total resection (GTR) was achieved in 59.4%. The morbidity rate, including hemiparesis, shunt-dependence, postop-hemorrhage, and tracheostomy was 22.6% and the mortality rate was 2.3%. In recurrent PCM surgery, CN deficits occurred in 16%. GTR could be achieved in three cases. Minor complications occurred in 20%. By applying the proposed new classification system to patients operated via standard craniotomies, the best outcome was observed in type I tumor patients (soft tumor consistency, smooth surface, plane arachnoid cleavage, and unilateral localization) with GTR in 78.7% (p < 0.001) and 11.9% new CN deficits (p = 0.006).

Conclusion

Standard craniotomies as the retrosigmoid or subtemporal/pterional approaches are often used for the resection of PCMs. Whether these approaches are sufficient for GTR—and avoidance of new neurological deficits—depends mainly on the localization and intrinsic tumor-specific features.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11060-022-04105-5.

Increased MIB-1 Labeling Index Is Associated with Abducens Nerve Morbidity in Primary Sporadic Petroclival Meningioma Surgery: Beyond Location and Approach

Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in patients who underwent the retrosigmoid approach in relation to the MIB-1 index. Thirty-two patients with primary sporadic PC MNG were retrospectively analyzed. Mean follow-up was 28.0 months. Analysis of the MIB-1 index was performed to evaluate the abducens nerve outcome. An optimal MIB-1 index cut-off value (<4/≥4) in the association with postoperative CN VI palsy was determined by ROC analysis (AUC: 0.74, 95% CI: 0.57−0.92). A new-onset CN VI palsy was present in 7 cases (21.88%) and was significantly associated with an increased MIB-1 index (≥4%, p = 0.025) and a peritumoral edema in the brachium pontis (p = 0.047) which might be caused by the increased growth rate. Tumor volume, cavernous sinus infiltration, auditory canal invasion, and Simpson grading were not associated with new CN VI deficits. Six (85.7%) of the 7 patients with both an increased MIB-1 index (≥4%) and new abducens nerve palsy still had a CN VI deficit at the 12-month follow-up. A peritumoral edema caused by a highly proliferative PC MNG with an elevated MIB-1 index (≥4%) is associated with postoperative abducens nerve deficits.

Midline Skull Base Meningiomas: Transcranial and Endonasal Perspectives

Simple Summary

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. Over time, several corridors have been proposed, each one carrying its own pros and cons. During the last decades, the endoscopic endonasal route has been asserted among the classic routes for a growing number of midline and paramedian lesions. Therefore, the aim of our paper is to present a comprehensive review of the indications and techniques for the management of skull base meningiomas, emphasizing the ambivalent and complementary role of the low and high routes.

Abstract

Skull base meningiomas have always represented a challenge for neurosurgeons. Despite their histological nature, they may be associated with unfavorable outcomes due to their deep-seated location and the surrounding neurovascular structures. The state of the art of skull base meningiomas accounts for both transcranial, or high, and endonasal, or low, routes. A comprehensive review of the pertinent literature was performed to address the surgical strategies and outcomes of skull base meningioma patients treated through a transcranial approach, an endoscopic endonasal approach (EEA), or both. Three databases (PubMed, Ovid Medline, and Ovid Embase) have been searched. The review of the literature provided 328 papers reporting the surgical, oncological, and clinical results of different approaches for the treatment of skull base meningiomas. The most suitable surgical corridors for olfactory groove, tuberculum sellae, clival and petroclival and cavernous sinus meningiomas have been analyzed. The EEA was proven to be associated with a lower extent of resection rates and better clinical outcomes compared with transcranial corridors, offering the possibility of achieving the so-called maximal safe resection.

Anterior petrosal (Kawase) approach to petroclival meningioma: 2-dimensional operative video

Petroclival meningiomas are challenging lesions that can be treated with several surgical approaches. The authors present a 66-year-old woman with a 1.6-cm left petroclival meningioma that was initially observed and then radiated after it grew 8 years later. Despite radiation, the tumor continued to grow to 4 cm; therefore, the patient was referred to the authors’ institution. A left anterior petrosal (Kawase) approach was performed. Postoperatively, the patient had transient cranial nerve IV and VI palsy that improved. The case presentation, surgical anatomy, operative technique, postoperative course, and different surgical approaches are reviewed. The patient gave verbal consent for participating in the surgical video.

The video can be found here: https://stream.cadmore.media/r10.3171/2022.1.FOCVID21259

Identification and Management of Aggressive Meningiomas

Meningiomas are common primary central nervous system tumors derived from the meninges, with management most frequently entailing serial monitoring or a combination of surgery and/or radiation therapy. Although often considered benign lesions, meningiomas can not only be surgically inaccessible but also exhibit aggressive growth and recurrence. In such cases, adjuvant radiation and systemic therapy may be required for tumor control. In this review, we briefly describe the current WHO grading scale for meningioma and provide demonstrative cases of treatment-resistant meningiomas. We also summarize frequently observed molecular abnormalities and their correlation with intracranial location and recurrence rate. We then describe how genetic and epigenetic features might supplement or even replace histopathologic features for improved identification of aggressive lesions. Finally, we describe the role of surgery, radiotherapy, and ongoing systemic therapy as well as precision medicine clinical trials for the treatment of recurrent meningioma.

Stereotactic radiosurgery in the management of petroclival meningiomas: a systematic review and meta-analysis of treatment outcomes of primary and adjuvant radiosurgery

PURPOSE

To summarize the clinical features and outcomes of petroclival meningioma patients treated with stereotactic radiosurgery (SRS) as either a primary or an adjuvant modality.

METHODS

Relevant articles were retrieved from PubMed, Scopus, Web of Science, and Cochrane. A systematic review and meta-analysis of treatment outcomes comparing primary and adjuvant SRS was conducted.

RESULTS

Seven articles comprising 722 cases were included. The mean tumor marginal dose was 13.5 Gy. After SRS, symptoms improved in 28.7%, remained unchanged in 61.3%, and worsened in 10.0% of the cohort. Tumor control was achieved in 94.8% of patients. The mean tumor volume change was -6.4 cm³. The 5-year and 10-year progression-free survival (PFS) rates were 91-100% and 69.6-89.9%, respectively. Overall, 61.9% of patients underwent primary radiosurgery, and 38.1% had adjuvant radiosurgery. Patients who had primary SRS reported higher rates of tumor control (94.3% vs. 88.2%) and fewer SRS-related complications (3.7% vs. 10.3%) than those who received adjuvant SRS (not accounting for microsurgical complications). The functional status of patients who had primary SRS was more likely to improve or remain unchanged, with an effect size of 1.12 (95% CI 1.1-1.25; I² = 0). Neither group displayed superiority in worsening functional outcomes or tumor control rate.

CONCLUSION

SRS of petroclival meningiomas was associated with excellent long-term PFS and local tumor control rates. Primary SRS was highly effective for patients with smaller volume lesions without clinically symptomatic mass effect. In patients who warrant initial resection, adjuvant radiosurgery remains an important modality to prevent regrowth while maintaining postresection function.

Factors Associated With Abducens Nerve Palsy in Patients Undergoing Surgery for Petroclival Meningiomas

BACKGROUND

During the surgical resection of petroclival meningiomas, preserving the cranial nerves is crucial. The abducens nerve is particularly vulnerable during surgery. However, the preoperative risk factors and postoperative prognosis of abducens nerve palsy (ANP) are poorly understood.

METHODS

We retrospectively analyzed 70 patients who underwent surgery for petroclival meningiomas between May 2010 and December 2019, divided into gross-total resection (GTR) and subtotal resection (STR) groups. The relationship of preoperative clinical factors with the incidence and recovery of postoperative ANP was analyzed.

RESULTS

Postoperative ANP was observed in 23 patients (32.9%). Multivariable logistic regression revealed that the tumor-to-cerebellar peduncle T2 imaging intensity index (TCTI) (P < 0.001) and internal auditory canal invasion (P = 0.033) contributed to postoperative ANP. GTR was achieved in 37 patients (52.9%), and 10 (27.0%) of them showed ANP. STR was achieved in 33 patients (47.1%), and 13 (39.4%) of them showed ANP. Recovery from ANP took a median of 6.6 months (range, 4.5-20.3 months). At 6 months after the operation, recovery of the abducens nerve function was observed in 16 patients (69.0%); of whom, 4 (40.0%) were in the GTR group and 12 (92.3%) were in the STR group (P = 0.025).

CONCLUSIONS

TCTI and internal auditory canal invasion were the risk factors for postoperative ANP. Although intentional STR did not prevent ANP immediately after the operation, recovery of the abducens nerve function after surgery was observed more frequently in the STR group than in the GTR group.

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.

Petroclival Meningiomas: A Simple System That Could Help in Selecting the Approach

BACKGROUND

Petroclival meningiomas (PCM) represent a neurosurgical challenge due to their strategic location close to the brainstem.

OBJECTIVE

To assess the applicability of a retrosigmoid approach (RSA) by analyzing the degree of displacement of the middle cerebellar peduncle (MCP) elicited by PCM.

METHODS

Patients with PCM were prospectively included and divided into those whose imaging studies showed that the posterior end of the MCP was displaced by the tumor and were eligible for and underwent RSA (group A) and those who were not eligible for RSA and who underwent surgery via a posterior transpetrosal approach (group B). We compared tumor behavior, clinical characteristic of patients and surgical results.

RESULTS

Twenty patients with PCM were enrolled and allocated to group A (n = 15) or group B (n = 5). The clinical manifestations were more severe in group B; tumors in this group were larger and gross total removal was achieved in only 1 patient (20%). In comparison, in 12 cases on group A, tumors could be totally removed (80%) and all of these patients could recover their quality of life after surgery.

CONCLUSION

To our knowledge, this study is the first to consider displacement of the MCP when establishing a suitable surgical approach for PCM. Our results suggest that the RSA becomes increasingly suitable when peduncle displacement is greater. By using this method, it was also possible to identify two types of tumors: petroclivals (group A) and clivopetrosals (group B), that show some specific clinical and surgical differences.

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.