Surgical Treatment of Spheno-Orbital Meningiomas: A Systematic Review and Meta-Analysis of Surgical Techniques and Outcomes

Spheno-Orbital Meningiomas: Advances in Reconstruction Workflow and Cosmetic/Functional Outcomes in the Digital Era

Spheno-orbital (SOM) meningioma is a rare subtype of skull base tumor characterized by the proliferation of arachnoid cap cells with intradural expansion, hyperostosis of calvarial and spheno-orbital bone, and consecutive infiltration of critical surrounding neurovascular structures of the frontotemporal base of the skull. Surgical resection is often challenging due to the infiltrative growth and the anatomically complex localization. In most cases, a microsurgical transcranial approach is performed, resulting in the need to reconstruct the orbit with or without a cranioplasty. This review highlights the evolution and current state-of-the-art reconstructive strategies used in SOM surgery.

Endoscopic transorbital approach for the management of spheno-orbital meningiomas: A systematic review and meta-analysis

INTRODUCTION

Meningioma is the most common benign tumor in the central nervous system and may arise from the sphenoid wing region. The tumor can involve the cavernous sinus medially, periorbital and orbital apex structures anteriorly, and infratemporal fossa inferiorly. Surgical approaches more currently used include the fronto-temporal approach, the pterional approach, and even the frontotemporal-orbitozygomatic approach. The results of safety and efficacy of Transorbital neuroendoscopic surgery for these cases are still unclear, with scarce literature on the subject.

OBJECTIVE

We assessed the safety and efficacy of Endoscopic Transorbital Approach (TOA) for the Management of Spheno-Orbital Meningiomas (SOMs).

METHODS

We searched Medline, Embase, Web of Science databases following PRISMA guidelines. We used single proportion analysis with 95% confidence intervals under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Eligible studies included those with ≥4 patients treated with endoscopic transorbital approach for the management of spheno-orbital meningioma.

RESULTS

Of the 3520 studies initially identified, 9 were selected, involving 216 patients, with a median follow-up of 20 months. For subtotal resection, pooled analysis confirmed a rate of 40% (CI: 24% to 57%) and a total resection rate of 46% (CI: 27% to 65%). The analysis also confirmed a rate of visual deficits of 10% (CI: 0% to 24%). The rate of cerebrospinal fluid leak was 2% (CI: 0% to 5%), and diplopia occurred in 8% of cases (CI: 0% to 18%).

CONCLUSION

ETOA is a safe and minimally invasive approach for spheno-orbital meningiomas, with low complication rates and effective cranial nerve preservation. However, its tumor resection efficacy is inferior to non-minimally invasive techniques, potentially affecting long-term outcomes. Further studies are needed to clarify its role and optimize tumor control in selected cases.

Biportal Endoscopic TransOrbital and transMaxillary Approach to the Cranio-Orbital Region and Middle Cranial Fossa: A Preliminary Analysis of Maneuverability

BACKGROUND AND OBJECTIVES

Traditional and well-established transcranial approaches to the spheno-orbital region and middle cranial fossa guarantee optimal intracranial exposure, and additional orbital and zygomatic osteotomies provide further control over extracranial components to be resected; however, these techniques come at the cost of additional morbidity. The introduction of minimally invasive endoscopic approaches and the conceptualization of the so-called "multiportal" paradigm might provide an alternative route. This preliminary study investigates the feasibility of the combined Biportal Endoscopic TransOrbital and transMaxillary Approach (bETOMA) approach to the spheno-orbital and middle cranial fossa regions.

METHODS

Using 4 silicon-injected adult cadaver heads (8 sides; 16 approaches), we systematically dissected through superior eyelid ETOA and endoscopic TMA approaches. The analysis focused on pterygopalatine, infratemporal, anterior and middle cranial fossae, Meckel cave, and cavernous sinus access. We evaluated the feasibility of bETOMA using linear distances, angles of attack, and exposure areas. We also introduced volume of operative maneuverability, its standardized derivative (sVOM), target distance, visuo-operative angle, and working zone volume as novel metrics.

RESULTS

The analysis revealed comparable angles of attack between approaches. ETOA and TMA exposure areas were 918.38 ± 223.93 mm 2 and 257.07 ± 86.07 mm 2 , respectively. TMA showed a larger VOM in the greater sphenoid wing, but ETOA offered superior distal maneuverability (sVOM: 5.39 ± 1.94 vs 2.54 ± 0.79 cm 3 ) and closer intracranial space access (27.45 vs 50.83 mm). The combined approaches yielded a mean working zone volume of 13.75 ± 3.73 cm 3 in the spheno-orbital interface.

CONCLUSION

The bETOMA approach provides adequate neurovascular exposure and maneuverability to the spheno-orbital region, infratemporal, and anterior and middle cranial fossae, addressing significant limitations of previously investigated monoportal techniques (ie, optic nerve decompression, hyperostotic bone resection, and infratemporal exposure). This combined minimally invasive approach might help manage lesions harbored within the cranio-orbital interface region invading the extracranial space.

Advantages and limitations of orbital rim resection in transorbital endoscopic approach: an anatomical study

BACKGROUND

Endoscopic transorbital approach (eTOA) has been recently proposed as an alternative skull base approach. However, its feasibility for deeper lesions can be hampered by a reduced surgical maneuverability. Aim of this study is to consider how its extension through orbital rim resection can overcome this limitation, and to compare two different techniques for its removal.

METHODS

Both sides of seven cadaveric fresh frozen head were dissected. Three different surgical approaches were performed consequentially (standard eTOA, its expansion with lateral orbital rim hinge removal, and with its complete resection). Distance to target and angle of attack have been measured for superior orbital fissure (SOF), lateral wall of cavernous sinus (LWCS), anterior clinoid process (ACP), foramen rotudum (FR) and foramen ovale (FO).

RESULTS

The angle of attack to the SOF (p = 0.01), to the LWCS (p = 0.001), to the ACP (p = 0.01), to the FR (p = 0.01) and to FO (p = 0.01) resulted larger in extended approaches with orbital rim resection, as well as the distance to target of LWCS (p = 0.04). Particularly, we observed that hinge lateral orbital rim removal improved the angle of attack to SOF (p = 0.02), APC (p = 0.01), FR (p = 0.01 and FO (p = 0.01) in comparison to the standard eTOA.

CONCLUSION

Our study confirms that the lateral orbital rim resection could significantly expand the surgical room and the instruments maneuverability for the considered target skull base targets. Its hinge removal could balance the clinical outcome with the increase of the angles of attack for the more medial and deeper structures.

Single-step 3D printing aided cranio-orbital reconstruction with patient specific polyetheretherketone implants after resection of benign spheno-orbital tumors

PURPOSE

Computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques have paved the way for single-step resections and cranio-orbital reconstructions with patient specific implants in spheno-orbital tumors. Here, we present our interdisciplinary maxillofacial and neurosurgical workflow and a case series of patients treated with this integrated approach.

METHODS

Patients, who underwent single-step resection of benign spheno-orbital tumors and cranio-orbital reconstruction with polyetheretherketone (PEEK) patient specific implants (PSI) from 2019 to 2024 in our institution were included. Three dimensional models of the tumor, the skull, the implants and the cutting guides were integrated into intraoperative neuronavigation and 3D printed at the point of care (POC) for surgical planning. Clinical data was retrospectively analyzed, pre- and postoperative Exophthalmic index (EI) was radiologically determined.

RESULTS

Eleven patients met inclusion criteria. Meningioma WHO grade 1 was the most common tumor entity (81.8%). In a majority of patients, exophthalmos was the presenting sign (63.6%). Postoperative cranial imaging revealed an optimal position of the PEEK implants with regredient EI in 88.9%. Four (36.4%) patients, of whom two (50%) had undergone prior tumor resections, suffered from surgical complications. The most commonly recorded complication was impaired wound healing (n = 2). Tumor recurrence was observed in one (9.1%) patient at six months follow-up.

CONCLUSIONS

Single-step resection and reconstruction in spheno-orbital tumors with PEEK PSIs is feasible and combines surgical expertise, virtual implant design and 3D printing techniques. Favorable aesthetical, visual and oncological outcomes were achieved in this cohort, despite a significant risk for postoperative complications.

Endoscopic transorbital approach for recurrent spheno-orbital meningiomas: single center case series

Endoscopic transorbital approaches (ETOAs) are finding wide application for skull base lesions, particularly for spheno-orbital meningiomas (SOMs). These tumors have high recurrence rates, and second surgery can often represent a challenge. In this study we analyze our experience of management of recurrent SOMs through a slightly modified eyelid crease approach. Between May 2016 and September 2023, in the Department of Neurosurgery of Fondazione IRCCS Policlinico San Matteo (Pavia, Italy), five consecutive recurrent SOMs have been treated using an endoscopic transorbital approach. Demographic data, preoperatory deficits, lesions characteristics, histology, grade of resection, eventual adjuvant treatments, complications, outcome in terms of symptoms improvement and cosmesis, and hospitalization are described. One patient maintained a right lateral rectus muscle palsy that was already present in the preoperatory, no cerebrospinal fluid (CSF) leaks were reported. All patients had postoperative periorbital edema, but no other systemic complication was found. All patients had proptosis improvement, two had visual acuity improvement, and best cosmetic outcome was obtained in all cases. Hospitalization varied between 4 and 6 days. ETOAs in the management of recurrent SOMs are safe and have good outcome. Right selection of patients is mandatory, but when feasible, endoscopic surgery can allow a virgin route to a previously operated tumor, guaranteeing a good strategic option.

Spheno-Orbital Meningiomas: The Rationale behind the Decision-Making Process of Treatment Strategy

Surgery stands as the primary treatment for spheno-orbital meningiomas, following a symptoms-oriented approach. We discussed the decision-making process behind surgical strategies through a review of medical records from 80 patients who underwent surgical resection at the University of Naples Federico II. Different surgical approaches were employed based on the tumor's location relative to the optic nerve's long axis, categorized into lateral (type I), medial (type II), and diffuse (type III). We examined clinical, neuroradiological, surgical, pathological, and outcome factors. Proptosis emerged as the most frequent symptom (97%), followed by visual impairment (59%) and ocular motility issues (35%). Type I represented 20%, type II 43%, and type III 17%. Growth primarily affected the optic canal (74%), superior orbital fissure (65%), anterior clinoid (60%), and orbital apex (59%). The resection outcomes varied, with Simpson grades I and II achieved in all type I cases, 67.5% of type II, and 18% of type III. Recurrence rates were highest in type II (41.8%) and type III (59%). Improvement was notable in proptosis (68%) and visual function (51%, predominantly type I). Surgery for spheno-orbital meningiomas should be tailored to each patient, considering individual characteristics and tumor features to improve quality of life by addressing primary symptoms like proptosis and visual deficits.

The Transorbital Approach: A Comprehensive Review of Targets, Surgical Techniques, and Multiportal Variants

The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method.

Correlation Analysis on Anatomical Variants of Accessory Foramina in the Sphenoid Bone for Oncological Surgery

The sphenoid bone presents several anatomical variations, including accessory foramina, such as the foramen meningo-orbitale, the foramen of Vesalius, the canaliculus innominatus and the palatovaginal canal, which may be involved in tumor invasion or surgery of surrounding structures. Therefore, clinicians and surgeons have to consider these variants when planning surgical interventions of the cranial base. The prevalence of each variant is reported in the published literature, but very little information is available on the possible correlation among different variants. Here, 300 CT scans of patients (equally divided among males and females) were retrospectively assessed to investigate the presence of the foramen meningo-orbitale, the foramen of Vesalius, the canaliculus innominatus and the palatovaginal canal. Possible differences in the prevalence of each accessory foramen according to sex were assessed, as well as possible correlations among different variants through the Chi-square test (p < 0.01). Overall, the prevalence of the foramen meningo-orbitale, the foramen of Vesalius, the canaliculus innominatus and the palatovaginal canal was 30.7%, 67.7%, 14.0% and 35.3%, respectively, without any difference according to sex (p > 0.01). A significant positive correlation was found between the foramen of Vesalius and canaliculus innominatus, both in males and in females (p < 0.01). In detail, subjects with canaliculus innominatus in 85.7-100.0% of cases also showed the foramen of Vesalius, independently from sex and side. The present study provided novel data about the prevalence of four accessory foramina of the sphenoid bone in an Italian population, and a correlation between the foramen of Vesalius and the canaliculus innominatus was found for the first time. As these accessory foramina host neurovascular structures, the results of this study are thus useful for appropriate planning surgical procedures that are tailored to the anatomical configuration of the patient and for improving techniques to avoid accidental injuries in cranial base surgery. Knowledge of the topography, frequencies and the presence/absence of these additional foramina are pivotal for a successful procedure. Clinicians and surgeons may benefit from these novel data for appropriate recognition of the variants, decision-making, pre-operative and treatment planning, improvement of the procedures, screening of patients and prevention of misdiagnosis.

The Transorbital Approach, A Game-Changer in Neurosurgery: A Guide to Safe and Reliable Surgery Based on Anatomical Principles

During the last few years, the superior eyelid endoscopic transorbital approach has been proposed as a new minimally invasive pathway to access skull base lesions, mostly in ophthalmologic, otolaryngologic, and maxillofacial surgeries. However, most neurosurgeons performing minimally invasive endoscopic neurosurgery do not usually employ the orbit as a surgical corridor. The authors undertook this technical and anatomical study to contribute a neurosurgical perspective, exploring the different possibilities of this novel route. Ten dissections were performed on ten formalin-fixed specimens to further refine the transorbital technique. As part of the study, the authors also report an illustrative transorbital surgery case to further detail key surgical landmarks. Herein, we would like to discuss equipment, key anatomical landmarks, and surgical skills and stress the steps and details to ensure a safe and successful procedure. We believe it could be critical to promote and encourage the neurosurgical community to overcome difficulties and ensure a successful surgery by following these key recommendations.