Petroclival Meningiomas: Factors Determining the Choice of Approach

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.

Critical appraisal of minimally invasive keyhole surgery for intracranial meningioma in a large case series

Background

Meningioma surgery has evolved over the last 20 years with increased use of minimally invasive approaches including the endoscopic endonasal route and endoscope-assisted and gravity-assisted transcranial approaches. As the “keyhole” concept remains controversial, we present detailed outcomes in a cohort series.

Methods

Retrospective analysis was done for all patients undergoing meningioma removal at a tertiary brain tumor referral center from 2008–2021. Keyhole approaches were defined as: use of a minimally invasive “retractorless” approach for a given meningioma in which a traditional larger approach is often used instead. The surgical goal was maximal safe removal including conservative (subtotal) removal for some invasive locations. Primary outcomes were resection rates, complications, length of stay and Karnofsky Performance Scale (KPS). Secondary outcomes were endoscopy use, perioperative treatments, tumor control and acute MRI FLAIR/T2 changes to assess for brain manipulation and retraction injury.

Results

Of 329 patients, keyhole approaches were utilized in 193(59%) patients (mean age 59±13; 30 (15.5%) had prior surgery) who underwent 213 operations; 205(96%) were skull base location. Approaches included: endoscopic endonasal (n = 74,35%), supraorbital (n = 73,34%), retromastoid (n = 38,18%), mini-pterional (n = 20,9%), suboccipital (n = 4,2%), and contralateral transfalcine (n = 4,2%). Primary outcomes: Gross total/near total (>90%) resection was achieved in 125(59%) (5% for petroclival, cavernous sinus/Meckel’s cave, spheno-cavernous locations vs 77% for all other locations). Major complications included: permanent neurological worsening 12(6%), CSF leak 2(1%) meningitis 2(1%). There were no DVTs, PEs, MIs or 30-day mortality. Median LOS decreased from 3 to 2 days in the last 2 years; 94% were discharged to home with favorable 90-day KPS in 176(96%) patients. Secondary outcomes: Increased FLAIR/T2 changes were noted on POD#1/2 MRI in 36/213(17%) cases, resolving in all but 11 (5.2%). Endoscopy was used in 87/139(63%) craniotomies, facilitating additional tumor removal in 55%. Tumor progression occurred in 26(13%) patients, mean follow-up 42±36 months.

Conclusions & relevance

Our experience suggests minimally invasive keyhole transcranial and endoscopic endonasal meningioma removal is associated with comparable resection rates and low complication rates, short hospitalizations and high 90-day performance scores in comparison to prior reports using traditional skull base approaches. Subtotal removal may be appropriate for invasive/adherent meningiomas to avoid neurological deficits and other post-operative complications, although longer follow-up is needed. With careful patient selection and requisite experience, these approaches may be considered reasonable alternatives to traditional transcranial approaches.

Retractorless Surgery for Petroclival Meningiomas via the Subtemporal Approach: A Try to Reduce Brain Retraction Injury

Purpose

To present our experience with retractorless surgery for resection of petroclival meningiomas (PCMs) via the subtemporal approach with routine operative instruments.

Methods

Clinical data of patients with PCMs who received surgical treatments via subtemporal approach were retrospectively analyzed. Patient demographics, duration of operation, extent of resection, postoperative brain injury rate, postoperative complication, and surgical outcome were reviewed.

Results

Twenty-nine consecutive patients with retractorless surgery via subtemporal approach performed between November 2018 and November 2021. The gross total resection rate was 82.8% (N = 24). The incidence of postoperative temporal lobe injury was 3.4% (N = 1). All the procedures were completed without fixed retraction or other specialized instruments.

Conclusions

Retractorless surgery via subtemporal approach is a reliable treatment option for PCMs, which can be completed with routine operative instruments.

Abordajes quirúrgicos de meningiomas petroclivales parte 1: anatomía microquirúrgica

Antecedentes:

Los meningiomas petroclivales son tumores benignos cuyo tratamiento microquirúrgico es uno de los mayores retos de la neurocirugía. El conocimiento profundo de la anatomía microquirúrgica y los abordajes quirúrgicos para el tratamiento de estos tumores es la primera etapa de aprendizaje para un manejo ideal. Este artículo se divide en dos partes: la primera parte presentará los resultados de la anatomía microquirúrgica relevantes para el manejo de los meningiomaspetroclivales. En la segunda parte, los autores correlacionan esta anatomía con 30 casos de meningiomas petroclivales operados por el autor principal (GRI).

Métodos:

Se disecaron ocho cabezas de cadáveres utilizando un microscopio quirúrgico en el laboratorio de microcirugía de la University of Arkansas for Medical Sciences. En los cerebros y en todas las cabezas, se inyectó silicona de colores para resaltar la diferencia entre las arterias y las venas. Los cadáveres fueron colocados en un fijador craneal tipo Mayfield, simulando el posicionamiento quirúrgico de los abordajes craneo-órbito-cigomatico, petrosectomía anterior y posterior y retrosigmoideo. Otras ocho cabezas de cadáveres fueron formolizadas y con los vasos inyectados con silicona de colores. Se realizaron los abordajes petroso anterior, petroso posterior y craneo-órbito-cigomático.

Resultados:

En el manejo de los meningiomas petroclivales se utilizan tres abordajes quirúrgicos principales: abordaje pterional y sus variantes, abordaje petroso y sus variantes y abordaje retrosigmoideo. Los abordajes endonasales endoscópicos extendidos tienen factores limitantes para su uso en este tipo de procedimiento. Para racionalizar la elección del abordaje quirúrgico, dividimos el clivus en tercios superior, medio e inferior.

Conclusíon:

Varios abordajes quirúrgicos dan acceso a la regiónpetroclival. El conocimiento práctico de la anatomía de esta región adquirido en el laboratorio de microcirugía es parte fundamental del cirujano que se propone operar meningiomas petroclivales.

Endoscopic Far-Lateral Supracerebellar Infratentorial Approach for Petroclival Region Meningioma: Surgical Technique and Clinical Experience

BACKGROUND

The management of petroclival region meningioma remains the ultimate achievement in neurosurgery, because of the formidable technical challenges involved.

OBJECTIVE

To describe the technique and feasibility of the purely endoscopic far-lateral supracerebellar infratentorial approach (EF-SCITA) for the treatment of petroclival region meningiomas.

METHODS

We reviewed the clinical data of 10 consecutive cases of petroclival region meningiomas treated with the EF-SCITA from August 2018 to August 2020. The clinical outcomes were analyzed. The patient was placed in the lateral position, and then, a "C" shaped incision and craniotomy with exposed sigmoid and transverse sinuses were performed. With the endoscopic holder, endoscopic procedures were performed using standard 2-hand microsurgical techniques. Whether the tentorium or Meckel cave was handled depended on the tumor extension.

RESULTS

The mean diameter was 45 × 25 mm. Dizziness and headache were the main symptoms. All 10 patients achieved gross total or subtotal resection (Petroclival Meningioma Grade I-III) with good neurological outcomes. The EF-SCITA provides satisfactory, direct exposure to the petroclival region. Cranial nerve deficits are the main postoperative complications. Two patients had a trochlear nerve injury, 3 patients had transient facial paralysis, and 2 patients had oculomotor paralysis (1 total and 1 incomplete), but both of them recovered during the follow-up period. One patient experienced an ipsilateral superior cerebellar artery infarction, and another patient had transient hemiparesis.

CONCLUSION

The EF-SCITA is effective for most petroclival region meningiomas, except for the cavernous sinus type. This approach simplifies craniotomy procedures, omits burdensome petrosectomy, and avoids crossing posterior neurovascular structures.

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.

Surgical Treatment and Clinical Outcomes of Petroclival Meningiomas: A Single-Center Experience of 107 Patients

Objective

This study aimed to establish optimal surgical strategies via reviewing the clinical outcomes of various surgical approaches for the pertroclival meningiomas (PCMs).

Methods

This retrospective study enrolled 107 patients with PCMs at the authors’ institution from year 2010 to 2020. Patient demographics, the clinical characteristics, various operative approaches, major morbidity, post-operative cranial nerve deficits and tumor progression or recurrence were analyzed.

Results

The subtemporal transtentorial approach (STA), the Kawase approach (KA), the retrosigmoid approach (RSA) and the anterior sigmoid approach (ASA), namely the posterior petrosal approach (PPA) were adopted for 17 cases, 22 cases, 31 cases and 34 cases respectively. Total or subtotal resection was achieved in 96 cases (89.7%). The incidence of new-onset and aggravated cranial nerve dysfunction were 13.1% (14/107) and 10.4% (15/144), respectively. Furthermore, 14 cases suffered from intracranial infection, 9 cases had cerebrospinal fluid leakage, and 3 cases sustained intracranial hematoma (1 case underwent second operation). The mean preoperative and postoperative Karnofsky Performance Status (KPS) score was 80 (range 60-100) and 78.6 (range 0-100), but this was not statistically significant (P>0.05). After a mean follow-up of 5.1 years (range 0.3- 10.6 years), tumor progression or recurrence was confirmed in 23 cases. Two cases died from postoperative complications.

Conclusions

For the treatment of PCMs, it is still a challenge to achieve total resection. With elaborate surgical plans and advanced microsurgical skills, most patients with PCMs can be rendered tumor resection with satisfactory extent and functional preservation, despite transient neurological deterioration during early postoperative periods.

Study of comparative surgical exposure to the petroclival region using patient-specific, petroclival meningioma virtual reality models

OBJECTIVE

Despite advancement of surgical techniques, the attachments of petroclival meningiomas near the central clival depression (CCD) remain difficult to visualize. With existing methods, the amount of tumor near the CCD that is inaccessible through various approaches cannot be compared. Tumors distort the brainstem, changing the size of the operative corridor for some but not all approaches; therefore, using cadavers with normal posterior fossae makes it impossible to compare different approaches to the tumor. The authors used virtual reality (VR) models created from the imaging data of patients to compare various surgical approaches that have otherwise been incomparable in previous studies.

METHODS

CT and MRI data obtained in 15 patients with petroclival meningiomas were used to create anatomically accurate 3D VR models. For each model, various surgical approaches were performed, and the surgical freedom to 6 targets of the regions were measured. Furthermore, portions of the tumor that were visually blocked by the brainstem or bony structures were segmented and recorded as blinded volumes for comparison.

RESULTS

The extended retrosigmoid approach generated excellent exposure of the petroclival region, but for most specimens, there was inaccessible tumor volume adjacent to the brainstem (mean 641.3 mm3, SE 161.8). In contrast, the brainstem sides of the tumors were well-visualized by all the transpetrosal approaches. The blinded volume of the tumor was largest for the retrolabyrinthine approach, and this was statistically significant compared with all other approaches (mean 2381.3 mm3, SE 185.4).

CONCLUSIONS

The authors performed a novel laboratory study by using patient CT and MRI data to generate 3D virtual models to compare surgical approaches. Since it is impossible to perform various approaches in separate surgeries in patients for comparison, VR represents a viable alternative for such comparative investigations.

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.

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.

Transarterial Embolization of a Parasellar Hypervascular Tumor

Embolization of hypervascular tumors has been widely performed for over four decades, particularly for preoperative meningioma. Several benefits of preoperative embolization have been reported, including reduced blood loss, surgical time and surgical complications, and improved outcomes. However, the technical details of both embolization and surgical procedures, and lesions widely vary. Thus, the actual benefits of preoperative embolization have not been clarified by prospective randomized studies. Procedure-related complications due to embolization developed in 3%-12% in previous studies. For parasellar lesions, both surgical resection and embolization have a higher risk of complication than for lesions at other locations because of the complicated neurovascular anatomy in the parasellar area. Therefore, close attention should be paid to the detailed vascular anatomy, embolic material, and related information for embolization and resection in individual cases to improve patient outcomes.

Surgical outcomes of anterior cerebellopontine angle meningiomas using the anterior transpetrosal approach compared with the lateral suboccipital approach

BACKGROUND

Anterior transpetrosal approach (ATPA) and lateral suboccipital approach (LSO) are the major surgical approaches for cerebellopontine angle (CPA) meningiomas. Particularly, anterior CPA meningiomas are challenging lesions to be treated surgically. To date, only a few studies have directly compared the outcomes of both approaches focusing on the anterior CPA meningiomas.

METHODS

For the comparative analysis, anterior CPA meningiomas that were eligible for both APTA and LSO were collected in our hospital from April 2005 to March 2017. Anterior CPA meningiomas targeted for this study were defined as follows: (1) without cavernous sinus, clivus, and middle cranial fossa extension, (2) the posterior edge is 1 cm behind the posterior wall of the internal auditory canal, and (3) the inferior edge is above the jugular tuberculum. Based on these criteria, the operative outcomes of 17 patients and 13 patients who were operated via ATPA and LSO were evaluated.

RESULTS

The complication rate of the LSO group was significantly higher than that of the ATPA group (30.7% vs. 0%, p = 0.033). The removal rate did not differ between the ATPA and LSO groups (97.35% vs. 99.23%, p = 0.12). The operative time was significantly shorter in the LSO group than in the ATPA group (304.3 min vs. 405.8 min, p = 0.036).

CONCLUSIONS

Although the LSO is more widely used for CPA meningiomas, ATPA is also considered for these anterior CPA meningiomas.

The historical perspective in approaches to the spheno-petro-clival meningiomas

The current literature regarding surgical treatment for tumors in the sphenopetroclival (SPC) region is merely scarce. Through a comprehensive literature review, we investigated the indications, outcomes, and complications of different surgical approaches to the SPC meningiomas. Given its complicated relationship between these slow-progression tumors and some critical neurovascular structures in the SPC region, surgical treatment of these tumors faces the challenge of achieving a maximal grade of resection, while preserving patient functionality. The development of new surgical techniques and approaches in recent years have permitted the advancement in the treatment of these tumors, with acceptable rates of morbidity and mortality. The choice of a surgical approach as a treatment for the lesion depends mainly on the type of tumor extension, surgeon's preferences, and the displacement of neurovascular structures. Rather than focusing on one single strategy of treatment, the skull-base surgeon should tailor the approach based on the origin and features of the lesion; as well as the peculiarities of the surgical anatomy. This strategy aims to decrease morbidity and to optimize tumor resection and patient quality of life.