The Role of the Transorbital Superior Eyelid Approach in the Management of Selected Spheno-orbital Meningiomas: In-Depth Analysis of Indications, Technique, and Outcomes from the Study of a Cohort of 35 Patients

Deep Temporal Muscle Pedicled Flap: A Novel Reconstruction Technique Following Transorbital Approach, Anatomic Study, and Surgical Implications

BACKGROUND AND OBJECTIVES

The temporalis muscle flap has historically been used for repairing defects from orbital procedures and is commonly used in cranial, oral, and facial reconstructions. However, its application for reconstructing the skull base after a transorbital approach has not been explored. Reconstruction after a transorbital intradural approach is still object of preclinical and clinical investigation, with various techniques emerging recently. This study introduces a novel method suitable for extensive resections of the skull base, including intradural resections of the anterior, middle, and posterior cranial fossae.The study aimed to investigate the feasibility of rotating a vascularized myofascial flap from the anterior third of the temporalis muscle onto the skull base, exploring its extension into the middle cranial fossa after drilling the greater wing of the sphenoid.

METHODS

Six endoscopic dissections were performed on formalin-fixed heads to illustrate the feasibility of preparing a deep fascia flap from the temporalis muscle. Red silicone latex was injected into the external carotid artery to confirm the vascular integrity of the deep temporal branches of the maxillary artery.

RESULTS

The deep temporalis myofascial flap offers a large, well-vascularized tissue that can be easily rotated to cover skull base defects after transorbital approaches. Its coverage extends from the middle and anterior cranial fossae to the infratemporal fossa and the lateral wall of the cavernous sinus. It also effectively covers dural defects at the temporal pole.

CONCLUSION

With an appropriate temporal bony window and sufficient exposure, it is feasible to endoscopically prepare a rotation flap from the anterior third of the temporalis muscle, minimizing the need for resecting the lateral orbital margin. This approach is a favorable alternative to traditional reconstruction techniques, offering quick setup in a single operative procedure. Future studies are needed to confirm minimal donor site morbidity regarding masticatory function.

Surgical risk of CSF leakage following endoscopic transorbital approach for anterior and middle skull base pathologies: a systematic review and meta-analysis

The endoscopic superior eyelid transorbital approach (SETOA) has demonstrated considerable versatility and effectiveness in managing various paramedian anterior and middle skull base pathologies. However, as with any relatively new technique, potential complications remain. We conducted an extensive literature search in MEDLINE and Embase in accordance with PRISMA guidelines including case reports and surgical series reporting cerebrospinal fluid (CSF) leak rate following SETOA for intracranial pathologies. Factors analyzed included lesion location (extra- or intra-axial), reconstruction techniques, and complication management. ROBINS-I tool was employed to assess the risk of bias. Twenty-five studies including 240 cases were eligible. The majority of lesions were intradural extra-axial (68.3%), while trigeminal schwannomas comprised all extradural cases (25.0%). Sixteen patients (6.6%) presented intradural intra-axial tumors. Osteodural reconstruction involved dural substitutes in one third of the cases (32.5%) either alone (14.2%) or combined with fat free graft (18.3%). CSF leak occurred in 6 patients (2.50%), mostly resolving via conservative management (66.6%). The risk of postoperative CSF leak was found to be significantly higher in patients undergoing resection for intra-axial tumors (OR 0.13, 95% CI: 0.04-0.49) compared to those undergoing resection for extra-axial (OR 0.01, 95% CI: 0.00-0.02; I2 = 0%; p < 0.001). Key limitations include the retrospective nature and small sample sizes among included studies as well as data heterogeneity and lack of standardized protocols for reconstruction across studies. SETOA appears safe for addressing selected extradural and intradural skull base pathologies with a low postoperative CSF leak rate. The natural repositioning of the orbital content to its original position may be instrumental in preventing its postoperative occurrence. The investigation followed a prespecified protocol registered on PROSPERO (PROSPERO 2024 CRD42024614111).

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.

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.

Endoscopic Transpterygoid Approach to Meckel's Cave: Technical Considerations and Retrospective Analysis of a Clinical Series

OBJECTIVE

Tumors located within the Meckel's cave (MC) pose a significant surgical challenge. Although several corridors to access this complex region have been described, the endoscopic transpterygoid approach (ETPA) and the endoscopic transorbital superior eyelid approach (ETOA) have emerged in recent years, as viable alternatives to traditional microsurgical transcranial approaches (MTA). To date, there is a limited literature on surgical series considering endoscopic-assisted approaches to the MC.

METHODS

We conducted a retrospective analysis of patients with primary MC tumors treated at our Institution between 2015 and 2022, specifically those managed via the ETPA assisted by intraoperative Endoscopic Diving Technique (EDT). Lesion resection extent was evaluated using pre- and post-intervention radiological images and surgical videos. Moreover, a literature review on ETPA was performed.

RESULTS

This series comprises 7 patients affected by 4 trigeminal schwannomas, 1 benign notochordal cell tumor, 1 dermoid cyst and 1 mesenchymal tumor. In 71 % of cases, trigeminal neuralgia was the presenting symptom. Post-operative clinical improvement was observed in all but one case. Notably, 85.7 % of patients achieved total or near-total resection (NTR), with the remaining case undergoing subtotal resection (STR). No significant intraoperative complications occurred, and no recurrences were observed during the mean follow-up period of 41 months.

CONCLUSIONS

In selected cases, the ETPA offers a direct and safe path to lesions located into the MC. This approach circumvents complications and constraints associated with ETOA or MTA. Moreover, the use of the EDT reduces manipulation of critical neurovascular structures, enhancing the efficacy of the ETPA.

Lateral transorbital neuroendoscopic approach for tumors of the orbital apex and spheno-orbital region: Technique, feasibility, efficacy, and safety based on a consecutive case series

Introduction

Surgical approaches for tumors of the orbital apex and the spheno-orbital region (SOR) comprehend medial and lateral corridors. The TransOrbital NeuroEndoscopic (TONE) approach has recently been reported as a possible effective alternative to the classic lateral corridors, but literature about is still underestimated.

Research question

The aim of this study was to make a critical appraisal of the results of using the lateral TONE approach in a monocentric consecutive series of SOR tumors.

Material and methods

Data from 38 consecutive patients managed surgically by means of a lateral TONE approach for a tumor involving the orbital apex and the SOR were collected and retrospectively reviewed from 2016, January 1st to 2023, December 31st.

Results

Mean age was 57 ± 14,9 years (23 female). 20 tumors were intraconal, with intradural involvement of SOR in 5 cases. Gross total resection was achieved in 82,9% of the 35 cases treated with a curative intent. Average operative time was 94,8 ± 28,5 and 140,2 ± 43,3 min for extraconal and intraconal tumors, respectively. Meningiomas had an overall prevalence of 31,6%. The complication rate was 21%, of which 87,5% transient. The recurrence rate was 0 for meningiomas and 14,3% for malignant tumors based on a follow-up of 55,3 ± 26,3 and 68,6 ± 17 months, respectively.

Discussion and conclusion

The lateral TONE approach is the approach of choice for tumors involving the lateral compartment of the orbital apex. It is also an effective and minimal invasive option in selected cases of spheno-orbital intradural tumors with no encasement of intracranial vessels.

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.

360 Degrees Endoscopic Access to and Through the Orbit

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Quantitative Anatomical Comparison of Surgical Approaches to Meckel's Cave

BACKGROUND

Meckel's cave is a challenging surgical target due to its deep location and proximity to vital neurovascular structures. Surgeons have developed various microsurgical transcranial approaches (MTAs) to access it, but there is no consensus on the best method. Newer endoscopic approaches have also emerged. This study seeks to quantitatively compare these surgical approaches to Meckel's cave, offering insights into surgical volumes and exposure areas.

METHODS

Fifteen surgical approaches were performed bilaterally in six specimens, including the pterional approach (PTA), fronto-temporal-orbito-zygomatic approach (FTOZA), subtemporal approach (STA), Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), endoscopic endonasal transpterygoid approach (EETPA), inferolateral transorbital approach (ILTEA) and superior eyelid approach (SEYA). All the MTAs were performed both with 10 mm and 15 mm of brain retraction, to consider different percentages of surface exposure. A dedicated navigation system was used to quantify the surgical working volumes and exposure of different areas of Meckel's cave (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada). Microsurgical transcranial approaches were quantified with two different degrees of brain retraction (10 mm and 15 mm). Statistical analysis was performed using a mixed linear model with bootstrap resampling.

RESULTS

The RSAS with 15 mm of retraction offered the maximum exposure of the trigeminal stem (TS). If compared to the KWA, the RSA exposed more of the TS (69% vs. 46%; p = 0.01). The EETPA and ILTEA exposed the Gasserian ganglion (GG) mainly in the anteromedial portion, but with a significant 20% gain in exposure provided by the EETPA compared to ILTEA (42% vs. 22%; p = 0.06). The STA with 15 mm of retraction offered the maximum exposure of the GG, with a significant gain in exposure compared to the STA with 10 mm of retraction (50% vs. 35%; p = 0.03). The medial part of the three trigeminal branches was mainly exposed by the EETPA, particularly for the ophthalmic (66%) and maxillary (83%) nerves. The EETPA offered the maximum exposure of the medial part of the mandibular nerve, with a significant gain in exposure compared to the ILTEA (42% vs. 11%; p = 0.01) and the SEY (42% vs. 2%; p = 0.01). The FTOZA offered the maximum exposure of the lateral part of the ophthalmic nerve, with a significant gain of 67% (p = 0.03) and 48% (p = 0.04) in exposure compared to the PTA and STA, respectively. The STA with 15 mm of retraction offered the maximum exposure of the lateral part of the maxillary nerve, with a significant gain in exposure compared to the STA with 10 mm of retraction (58% vs. 45%; p = 0.04). The STA with 15 mm of retraction provided a significant exposure gain of 23% for the lateral part of the mandibular nerve compared to FTOZA with 15 mm of retraction (p = 0.03).

CONCLUSIONS

The endoscopic approaches, through the endonasal and transorbital routes, can provide adequate exposure of Meckel's cave, especially for its more medial portions, bypassing the impediment of major neurovascular structures and significant brain retraction. As far as the most lateral portion of Meckel's cave, MTA approaches still seem to be the gold standard in obtaining optimal exposure and adequate surgical volumes.

Reconstruction of orbital walls after resection of cranioorbital meningiomas: a systematic review and meta-analysis of individual patient data

Following meningioma removal, there are numerous methods available for reconstructing the orbital wall. This systematic review seeks to summarize the published data on the surgical treatment of cranioorbital meningiomas, and to analyze the effectiveness and safety of various techniques and materials used for the reconstruction of bony orbital walls. We conducted a search of the two databases and included original articles with a series of 10 or more cases. Descriptive statistics and meta-analysis of individual patient date were performed. The analysis included a total of 858 patients from 29 sources. No reconstruction of the orbital walls was performed in 525 patients (61.2%), while 333 observations (38.8%) involved resection followed by reconstruction. A relative improvement in eye position was achieved in 94.4% of cases with a 95% CI of (88.92%; 97.25%). However, normalization of eye position, regardless of reconstruction technique, was only present in 6.22% of cases with a 95% CI of (1.24%; 25.9%). The best results were observed with the use of autologous bone implants (64%, 95% CI [33.35%; 86.33%]) and titanium implants (55.78%, 95% CI [2.86%; 98.18%]). In cases of endoscopic resection and microsurgical resection without reconstruction, symmetrical eye position accounted for only 1.94% (95% CI [0%; 96.71%]) and 2.35% (95% CI [0.13%; 31.23%]), respectively. The frequency of normalization of eye position differed significantly (p < 0.01) among the subgroups. A total of 49 postoperative complications were registered, with wound infection (1.52%, 95% CI [0.86%; 2.65%]) and wound cerebrospinal fluid leak (1.32%, 95% CI [0.6%; 2.91%]) being the most frequent. No significant differences were found in the rates of complications among the different subgroups. One of the primary objectives of cranioorbital meningioma surgery is to correct the position of the eye. Simultaneous reconstruction of the bony orbital leads to better cosmetic outcomes. Postoperative complications did not depend on the reconstructive technique or the materials.

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.

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

BACKGROUND

Spheno-orbital meningiomas (SOMs) are rare tumors arising from the meninges surrounding the sphenoid bone and orbital structures. Surgical resection is the primary treatment approach for SOMs. Several surgical approaches have been described during the decades, including microsurgical transcranial (MTAs), endoscopic endonasal (EEAs), endoscopic transorbital (ETOAs), and combined approaches, and the choice of surgical approach remains a topic of debate.

PURPOSE

This systematic review and meta-analysis aim to compare the clinical and surgical outcomes of different surgical approaches used for the treatment of SOMs, discussing surgical techniques, outcomes, and factors influencing surgical decision making.

METHODS

A comprehensive literature review of the databases PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted for articles published on the role of surgery for the treatment of SOMs until 2023. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Meta-analysis was performed to estimate pooled event rates and assess heterogeneity. Fixed- and random-effects were used to assess 95% confidential intervals (CIs) of presenting symptoms, outcomes, and complications.

RESULTS

A total of 59 studies comprising 1903 patients were included in the systematic review and meta-analysis. Gross total resection (GTR) rates ranged from 23.5% for ETOAs to 59.8% for MTAs. Overall recurrence rate after surgery was 20.7%. Progression-free survival (PFS) rates at 5 and 10 years were 75.5% and 49.1%, respectively. Visual acuity and proptosis improvement rates were 57.5% and 79.3%, respectively. Postoperative cranial nerve (CN) focal deficits were observed in 20.6% of cases. The overall cerebro-spinal fluid (CSF) leak rate was 3.9%, and other complications occurred in 13.9% of cases. MTAs showed the highest GTR rates (59.8%, 95%CI = 49.5-70.2%; p = 0.001) but were associated with increased CN deficits (21.0%, 95%CI = 14.5-27.6%). ETOAs had the lowest GTR rates (23.5%, 95%CI = 0.0-52.5%; p = 0.001), while combined ETOA and EEA had the highest CSF leak rates (20.3%, 95%CI = 0.0-46.7%; p = 0.551). ETOAs were associated with better proptosis improvement (79.4%, 95%CI = 57.3-100%; p = 0.002), while anatomical class I lesions were associated with better visual acuity (71.5%, 95%CI = 63.7-79.4; p = 0.003) and proptosis (60.1%, 95%CI = 38.0-82.2; p = 0.001) recovery. No significant differences were found in PFS rates between surgical approaches.

CONCLUSION

Surgical treatment of SOMs aims to preserve visual function and improve proptosis. Different surgical approaches offer varying rates of GTR, complications, and functional outcomes. A multidisciplinary approach involving a skull base team is crucial for optimizing patient outcomes.

Surgical Anatomy of the Microscopic and Endoscopic Transorbital Approach to the Middle Fossa and Cavernous Sinus: Anatomo-Radiological Study with Clinical Applications

BACKGROUND

The transorbital approaches (TOAs) have acquired growing notoriety, thanks to their ability to offer alternative corridors to the skull base. However, the limited access and the unfamiliarity with this surgical perspective make recognition of key landmarks difficult, especially for less experienced surgeons. The study wants to offer a detailed description of the anatomy to comprehend the potential and limitations of TOAs.

METHODS

Measurements of the orbit region and the surrounding areas were performed on two hundred high-resolution CT scans and thirty-nine dry skulls. Five specimens were dissected to illustrate the TOA, and one was used to perform the extradural clinoidectomy. Three clinical cases highlighted the surgical applications.

RESULTS

A step-by-step description of the key steps of the TOA was proposed and a comparison with the transcranial anterior clinoidectomy was discussed. The mean work distance was 6.1 ± 0.4 cm, and the lateral working angle increased 20 ± 5.4° after removing the lateral orbital rim.

CONCLUSIONS

TOAs are indicated in selected cases when tumor involves the lateral portion of the cavernous sinus or the middle skull base, obtaining a direct decompression of the optic nerve and avoiding excessive manipulation of the neurovascular structures. Comprehension of surgical anatomy of the orbit and its surrounding structures is essential to safely perform these approaches.

Endoscopic Transorbital Approach for Spheno-Orbital Tumors: Case Series and Systematic Review of Literature

BACKGROUND

Transorbital neuroendoscopic surgery (TONES) comprises a group of approaches with indications expanding from orbital tumors to more complex skull base lesions. We analyzed the role of the endoscopic transorbital approach (eTOA) for spheno-orbital tumors, reporting the results of our clinical series and of a systematic review of the literature.

MATERIALS AND METHODS

All patients operated on from 2016 to 2022 at our institution for a spheno-orbital tumor through an eTOA were included in a clinical series, and a systematic review of the literature was performed.

RESULTS

Our series consisted of 22 patients (16 females, mean age 57 ± 13 years). Gross tumor removal was achieved in 8 patients (36.4%) after the eTOA and in 11 (50.0%) after a multistaged strategy combining the eTOA with the endoscopic endonasal approach. Complications included 1 chronic subdural hematoma and 1 permanent extrinsic ocular muscle deficit. Patients were discharged after 2.4 ± 1.3 days. The most common histotype was meningioma (86.4%). Proptosis improved in all cases, visual deficit in 66.6%, and diplopia in 76.9%. These results were confirmed by the review of the 127 cases reported in the literature.

CONCLUSIONS

Despite its recent introduction, a significant number of spheno-orbital lesions treated with an eTOA are being reported. Its main advantages are favorable patient outcome and optimal cosmetic results, with minimal morbidity and quick recovery. This approach can be combined with other surgical routes or adjuvant therapies for complex tumors. However, it is a technically demanding procedure, requiring specific skills in endoscopic surgery, that should be reserved to dedicated centers.

Comparison of Accessibility to Cavernous Sinus Areas Throughout Endonasal, Transorbital, and Transcranial Approaches: Anatomic Study With Quantitative Analysis

BACKGROUND

The cavernous sinus (CS) is accessed through several approaches, both transcranially and endoscopically. The transorbital endoscopic approach is the newest proposed route in the literature.

OBJECTIVE

To quantify and observe the areas of the CS reach from 2 endoscopic and 1 transcranial approaches to the CS in the cadaver laboratory.

METHODS

Six CSs were dissected through endoscopic endonasal, transorbital endoscopic, and transcranial pterional approaches, with previous implanted references for neuronavigation during the dissection. Point registration was used to mark the CS exposure and limits through each approach for later area and volume quantification through a computerized technique.

RESULTS

The endoscopic endonasal approach reaches most of the CS except part of the sinus's superior, lateral, and posterior regions. The area exposed through this approach was 210 mm 2 , and the volume was 1165 mm 3 . The transcranial pterional approach reached the superior and part of the lateral sides of the sinus, not allowing good access to the medial side. The area exposed through this approach was 306 m 2 , whereas the volume was 815 m 3 . Finally, the transorbital endoscopic approach accessed the whole lateral side of the sinus but not the medial one. The area exposed was the greatest, 374 m 2 , but its volume was the smallest, 754 m 3 .

CONCLUSION

According to our results, the endonasal endoscopic approach is the direct route to access the medial, inferior, and part of the superior CS compartments. The transorbital approach is for the lateral side of the CS. Finally, the transcranial pterional approach is the one for the superior side of the CS.

Spheno-Orbital Meningioma and Vision Impairment-Case Report and Review of the Literature

(1) Background: Spheno-orbital meningioma (SOM) is a very rare subtype of meningioma which arises from the sphenoid ridge with an orbital extension. It exhibits intraosseous tumor growth with hyperostosis and a widespread soft-tissue growth at the dura. The intra-orbital invasion results in painless proptosis and slowly progressing visual impairment. (2) Methods: We present a case of a 46-year-old woman with SOM and compressive optic nerve neuropathy related to it. Her corrected distance visual acuity (CDVA) was decreased to 20/100, she had extensive visual field (VF) scotoma, dyschromatopsia, impaired pattern-reversal visual-evoked potential (PVEP), and decreased thicknesses of the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC), measured with the swept-source optical coherence tomography (SS-OCT), and a pale optic nerve disc in her left eye. Brain CT and MRI showed a lesion at the base of the anterior cranial fossa, involving the sphenoid wing and orbit. Pterional craniotomy and a partial removal of the tumor at the base of the skull and in the left orbit with the resection of the lesional dura mater and bony defect reconstruction were performed. (3) Results: The histological examination revealed meningothelial meningioma (WHO G1). Decreased CDVA and VF defects completely recovered, and the color vision score and PVEP improved following the surgery, but RNFL and GCC remained impaired. No tumor recurrence was observed at a follow-up of 78 months. (4) Conclusions: Optic nerve dysfunction has the capacity to improve once the compression has been relieved despite the presence of the structural features of optic nerve atrophy.

Functional and clinical outcomes after superior eyelid transorbital endoscopic approach for spheno-orbital meningiomas: illustrative case and literature review

The pattern of growth of spheno-orbital meningiomas accounts for the main presenting symptoms, such as proptosis, eye motility deficit, visual impairment, diplopia. As these are benign tumors, the postoperative patient's quality of life is an important factor to consider during the preoperative planning. A detailed literature review of superior eyelid transorbital endoscopic approach for spheno-orbital meningiomas, including our own case, was made. A Medline search up to March 2022 in PubMed online electronic database was made using the following key phrases: "superior eyelid endoscopic transorbital approach spheno-orbital meningiomas," "superior eyelid endoscopic transorbital approach," "spheno-orbital meningiomas endoscopic approach." The inclusion criteria were surgical series, reviews, and case reports in English language, as well as papers written in other languages, but including the abstract in English. Cadaveric studies, multiportal combined approaches for SOM, were excluded. The literature review has disclosed five studies for a total of 65 patients, whose demographic, clinical, pathological, surgical, complications, and outcome data were analyzed. Functional and esthetic outcome data after superior eyelid transorbital approach are the following: improvement of proptosis (100%), of visual deficits (66.66%) and of ocular paresis (75%), with only 11 complications (4 trigeminal dysesthesia, 2 CSF leak, 2 wound complications, 1 upper eyelid necrosis, 1 hemorrhage of surgical field, 1 keratitis) reported, but at the expense of extent of resection (gross total resection 33.39%). Based on the outcome data, the superior eyelid transorbital endoscopic approach results in a suitable operative technique for selected spheno-orbital meningiomas.

Endoscopic transorbital avenue to the skull base: Four-step conceptual analysis of the anatomic journey

Background

In the last decades, skull base surgery had passed through an impressive evolution. The role of neuroanatomic research has been uppermost, and it has played a central role in the development of novel techniques directed to the skull base. Indeed, the deep and comprehensive study of skull base anatomy has been one of the keys of success of the endoscopic endonasal approach to the skull base. In the same way, dedicated efforts expended in the anatomic lab has been a powerful force for the growth of the endoscopic transorbital approach to the lateral skull base.

Therefore, in this conceptual paper, the main steps for the anatomic description of the endoscopic transorbital approach to the skull base have been detailed.

Methods

The anatomic journey for the development of the endoscopic transorbital approach to the skull base has been analyzed, and four “conceptual” steps have been highlighted.

Results

As neurosurgeons, the eyeball has always represented a respectful area: to become familiar with this complex and delicate anatomy, we started by examining the orbital anatomy on a dry skull (step 1). Hence, step 1 is represented by a detailed bone study; step 2 is centered on cadaveric dissection; step 3 consists in 3D quantitative assessment of the novel endoscopic transorbital corridor; and finally, step 4 is the translation of the preclinical data in the real surgical scenario by means of dedicated surgical planning.

Conclusions

The conceptual analysis of the anatomic journey for the description of the endoscopic transorbital approach to the skull base resulted in four main methodological steps that should not be thought strictly consequential but rather interconnected. Indeed, such steps should evolve following the drives that can arise in each specific situation. In conclusion, the four-step anatomic rehearsal can be relevant for the description, diffusion, and development of a novel technique in order to facilitate the application of the endoscopic transorbital approach to the skull base in a real surgical scenario.

Endoscopic-assisted transorbital surgery: Where do we stand on the scott’s parabola? personal considerations after a 10-year experience

Transorbital approaches are genuinely versatile surgical routes which show interesting potentials in skull base surgery. Given their “new” trajectory, they can be a very useful adjunct to traditional routes, even being a valid alternative to them in some cases, and add valuable opportunities in selected patients. Indications are constantly expanding, and currently include selected intraorbital, skull base and even intra-axial lesions, both benign and malignant. Given their relatively recent development and thus unfamiliarity among the skull base community, achieving adequate proficiency needs not only a personalized training and knowledge but also, above all, an adequate case volume and a dedicated setting. Current, but mostly future, applications should be selected by genetic, omics and biological features and applied in the context of a truly multidisciplinary environment.