Use of endoscopic transorbital and endonasal approaches for 360° circumferential access to orbital tumors

Robotic assisted orbital surgery for resection of advanced periocular tumours - a case series report on the feasibility, safety and outcome

PURPOSE

Orbital surgery benefits from well-designed instrumentation that offers gentle tissue manipulation, high manoeuvrability and control. Nevertheless, in confined spaces, tissue manipulation must be accomplished with exceptionally high accuracy and precision. This is where robotic surgery offers an advantage. We aimed to evaluate a robotic-assisted surgical system's feasibility, safety and outcome in assisting tumour clearance.

PATIENTS AND METHODS

A case series of patients with advanced periocular tumours undergoing robotic-assisted globe-sparing resection was performed using the DaVinci XI system (Intuitive Surgical, Inc). Institutional ethics and multidisciplinary approval were sought in all cases.

RESULTS

Four patients with advanced periocular tumours underwent robotic-assisted orbital surgery at a mean age of 63 years (range 42-86). Two patients were diagnosed with squamous cell carcinoma, and two had basal cell carcinoma. One patient was found to have positive lymph nodes at the time of surgery and underwent simultaneous parotidectomy and lymph node clearance. Clear resection of the primary tumour was achieved in all patients; three patients underwent further resection due to narrow margins prior to reconstruction. Patients were follow-up for at least one year, and three remained disease-free. One patient with pre-existing extra-orbital disease developed metastatic disease four months post-op. All patients preserved vision peri-operatively, with no complaints of diplopia. Moderate ocular surface disease was noted in two patients.

CONCLUSION

Our series highlights the potential advantage of three-dimensional optics, multi-directional instrumentation and motion scaling technology to achieve globe-sparing tumour resection in advanced periocular tumours. However, further robotic instrumentation development is required for orbital surgery.

Lateral micro-orbitotomy as the technique of choice for orbital pseudotumor in IgG4-RD. Case report and review of the literature

Immunoglobulin G4-related disease (IgG4-RD) is characterized by a systemic fibroinflammatory infiltrate that often involves the orbit in addition to other tissues. Thus it has to be considered in the differential diagnosis of orbital tumors. We report the clinical case of a 64-year-old woman who presented with right mydriasis, progressive proptosis and paralysis of the third cranial nerve of 1 year of evolution. Cranial MRI identified an intraconal lesion of the right orbit, located between the external and inferior rectus muscles and the optic nerve, and she was scheduled for surgery by transcranial approach with lateral micro-orbitomy. A satisfactory macroscopic excision was achieved with no remarkable complications and a definitive deferred histological result of pseudotumor by IgG4-RD. Follow-up for 24 months showed no tumor recurrence, and the patient clinically improved from ophthalmoplegia. This case highlights the efficacy of lateral orbitotomy in the etiologic diagnosis and successful therapeutic outcome of complex orbital lesions associated with IgG4-RD pseudotumor.

Neurophysiologic Monitoring of Oculomotor Nerves During Transorbital Surgery: Proof of Concept and Anatomic Demonstration

BACKGROUND AND OBJECTIVES

Transorbital neuroendoscopic surgery (TONES) is continuously evolving and gaining terrain in approaching different skull base pathologies. The objective of this study was to present our methodology for introducing recording electrodes, which includes a new transconjunctival pathway, to monitor the extraocular muscle function during TONES.

METHODS

A translational observational study was performed from an anatomic demonstration focused on the transconjunctival electrode placement technique to a descriptive analysis in our series of 6 patients operated using TONES in association with intraoperative neurophysiologic monitoring of the oculomotor nerves from 2017 to 2023. The stepwise anatomic demonstration for the electrode placement and correct positioning in the target muscle was realized through cadaveric dissection. The descriptive analysis evaluated viability (obtention of the electromyography in each cranial nerve [CN] monitored), security (complications), and compatibility (interference with TONES).

RESULTS

In our series of 6 patients, 16 CNs were correctly monitored: 6 (100%) CNs III, 5 (83.3%) CNs VI, and 5 (83.3%) CNs IV. Spontaneous electromyography was registered correctly, and compound muscle action potential using triggered electromyography was obtained for anatomic confirmation of structures (1 CN III and VI). No complications nor interference with the surgical procedure were detected.

CONCLUSION

The methodology for introducing the recording electrodes was viable, secure, and compatible with TONES.

Endoscopic transorbital decompression for traumatic superior orbital fissure syndrome: from cadaveric study to clinical application

PURPOSE

The endoscopic endonasal approach (EEA) is a minimally invasive and promising modality for treating traumatic superior orbital fissure (SOF) syndrome (tSOFS). Recently, the endoscopic transorbital approach (ETOA) has been considered an alternative method for reaching the anterolateral skull base. This study accessed the practicality of using the ETOA to treat SOF decompression using both cadaveric dissection and clinical application.

METHODS

Bilateral anatomic dissections were performed on four adult cadaveric heads using the ETOA and EEA to address SOF decompression. The ETOA procedure for SOF decompression is described, and the extent of SOF decompression was compared between the ETOA and EEA. The clinical feasibility of the ETOA for treating SOF decompression was performed in two patients diagnosed with tSOFS.

RESULTS

ETOA allowed for decompression over the lateral aspect of the SOF, from the meningo-orbital band superolaterally to the maxillary strut inferomedially. By contrast, the EEA allowed for decompression over the medial aspect of the SOF, from the lateral opticocarotid recess superiorly to the maxillary strut inferiorly. In both patients treated using the ETOA and SOF decompression, the severity of ophthalmoplegia got obvious improvement.

CONCLUSIONS

Based on the cadaveric findings, ETOA provided a feasible access pathway for SOF decompression with reliable outcomes, and our patients confirmed the clinical efficacy of the ETOA for managing tSOFS.

Gross-total resection in optic nerve sheath meningiomas: minimally invasive and cosmetic pleasing

PURPOSE

The optic nerve sheath meningioma (ONSM) is one of the most challenging tumors in orbital surgery. From the perspective of mental health and patient needs, we analyzed the necessity and importance of the endoscopic transnasal approach (ETA) combined with optic nerve transection (ONT) in gross-total resection (GTR) in ONSM patients with residual vision and aim to broaden the use of ONT for specific people.

METHODS

The authors included patients with ONSMs who were treated between 2014 and 2022. We divided those cases into two groups named ETA group and lateral orbitotomy approach (LOA) group. We present the application of ETA and analyze the preoperative indication of the ONT and compared the advantages and disadvantages between ETA and LOA. The degree of tumor resection was based on imaging and surgical evaluation.

RESULTS

A total of 23 patients with ONSM were included. Sixteen patients underwent ETA, and seven underwent LOA. Among ETA cases, GTR was achieved in 14 patients with ONT and most patients maintained normal eye movement function (75%) and morphology (93.75%). In the ETA group, 14 patients experienced vision loss, while two other patients saw improvements in vision. And proptosis was alleviated (5.20 ± 2.34 vs 0.27 ± 0.46, p < 0.0001). Six patients with blindness and proptosis of the LOA group resulted in GTR with ONT and ophthalmectomy. Although intracranial extension and recurrence included no cases in the two groups, a significant psychological gap was presented due to cosmetic problems.

CONCLUSIONS

Under the premise of reducing damage and improving aesthetics, the selection of ETA combined with ONT to gross-total resect ONSMs successfully provides a minimally invasive access with acceptable complications. As an important adjunct to GTR in the surgical treatment of ONSM, the scope of ONT application should be expanded to relieve the patient's psychological burden.

Complications of the Superior Eyelid Endoscopic Transorbital Approach to the Skull Base: Preliminary Experience With Specific Focus on Orbital Outcome

BACKGROUND

The endoscopic superior eyelid approach is a relatively novel mini-invasive technique that is currently investigating for skull base cancers. However, questions remain regarding specific approach-related complications when treating different skull base tumors. This study aims to analyze any surgical complications that occurred in our preliminary consecutive experience, with specific focus on orbital outcome.

METHODS

A retrospective and consecutive cohort of patients treated via a superior eyelid endoscopic transorbital approach at the Division of Neurosurgery of the Hospital Clinic in Barcelona was analyzed. Patients features were described in detail. Complications were divided into 2 groups to analyze separately the approach-related complications, and those resulting from tumor removal. The ocular complications were subdivided into early ocular status (<3 weeks), late ocular status (3-8 weeks), and persistent ocular complications. The "Park questionnaire" was used to determine patient's satisfaction related to the transorbital approach.

RESULTS

A total of 20 patients (5 spheno-orbital meningiomas, 1 intradiploic Meningioma, 2 intraconal lesions, 1 temporal pole lesion, 2 trigeminal schwannoma, 3 cavernous sinus lesions, and 6 petroclival lesions) were included in the period 2017-2022. Regarding early ocular status, upper eyelid edema was detected in all cases (100%) associated with diplopia in the lateral gaze in 30% of cases, and periorbital edema in 15% of cases. These aspects tend to resolve at late ocular follow-up (3-8 weeks) in most cases. Regarding persistent ocular complications, in one case of intraconal lesion, a limitation of eye abduction was detected (5%). In another patient with intraconal lesion, an ocular neuropathic pain was reported (5%). In 2 cases of petroclival menigioma, who were also treated with a ventriculo-peritoneal shunt, slight enophthalmus was observed as a persistent complication (10%). According to the Park questionnaire, no cosmetic complaints, no head pain, no palpable cranial irregularities, and no limited mouth opening were reported, and an average of 89% of general satisfaction was encountered.

CONCLUSIONS

The superior eyelid endoscopic transorbital approach is a safe and satisfactory technique for a diversity of skull base tumors. At late follow-up, upper eyelid edema, diplopia, and periorbital edema tend to resolve. Persistent ocular complications are more frequent after treating intraconal lesions. Enophthalmus may occur in patients with associated ventriculo-peritoneal shunt. According to patient's satisfaction, fairly acceptable results are attained.

Transorbital Exposure of the Internal Carotid Artery: A Detailed Anatomic and Quantitative Roadmap for Safe Successful Surgery

BACKGROUND AND OBJECTIVES

The superior eyelid endoscopic transorbital approach has rapidly gained popularity among neurosurgeons for its advantages in the treatment, in a minimally invasive fashion, of a large variety of skull base pathologies. In this study, an anatomic description of the internal carotid artery (ICA) is provided to identify risky zones related to lesions that may be approached using this technique. In this framework, a practical roadmap can help the surgeon to avoid potentially life-threatening iatrogenic vascular injuries.

METHODS

Eight embalmed adult cadaveric specimens (16 sides) injected with a mixture of red latex and iodinate contrast underwent superior eyelid transorbital endoscopic approach, followed by interdural dissection of the cavernous sinus, extradural anterior clinoidectomy, and anterior petrosectomy, to expose the entire "transorbital" pathway of the ICA. Furthermore, the distance of each segment of the ICA explored by means of the superior eyelid endoscopic transorbital approach was quantitatively analyzed using a neuronavigation system.

RESULTS

We exposed 4 distinct ICA segments and named the anatomic window in which they are displayed in accordance with the cavernous sinus triangles distribution of the middle cranial fossa: (1) clinoidal (Dolenc), (2) infratrochlear (Parkinson), (3) anteromedial (Mullan), and (4) petrous (Kawase). Critical anatomy and key surgical landmarks were defined to further identify the main danger zones during the different steps of the approach.

CONCLUSION

A detailed knowledge of the reliable surgical landmarks of the course of the ICA as seen through an endoscopic transorbital route and its relationship with the cranial nerves are essential to perform a safe and successful surgery.

Endoscopic approaches to the orbit: Transnasal and transorbital, a retrospective case series

Introduction

Orbital pathologies requiring surgery are traditionally treated by open approach with different techniques depending on the lesion location. Recently, minimally invasive endoscopic approaches, such as the Endoscopic Endonasal Approach (EEA) and the Endoscopic Transorbital Approach (ETA) have been introduced in orbital surgery.

Research question

The purpose of this study is to report the combined experience of the Neurosurgical and Ear-Nose-Throat (ENT) Units in the endoscopic approach of orbital pathologies.

Material and methods

We retrospectively retrieved data on patients treated at our Institution between 2016 and 2021 with endoscopic approach for orbital pathologies. The Clavien-Dindo classification and the Scar Cosmesis Assessment and Rating (SCAR) Scale have been used to assess complications and cosmetic outcomes.

Results

39 patients met the inclusion criteria. EEA (15 patients) or ETA (20 patients) were chosen to approach the lesions. In three cases we used a combination of endoscopic and anterior orbitotomy and in one patient a combination of EEA + ETA. The type of procedure performed was orbital biopsy (9 cases), orbital decompression (6 cases), subtotal resection of the lesion (STR) (8 cases) and total resection of the lesion (GTR) (16 cases). The more frequent postoperative complications were diplopia (5.1%, with 1 case of permanent diplopia), trigeminal paraesthesia and dysesthesia (5.1%), palpebral edema (17.9%), periorbital ecchymosis (7.7%). Mean follow up time was 21 months (range 2-63 months).

Discussion and conclusion

Endoscopic approaches to orbital compartments provide minimally invasive access to every orbital compartment with low complications rate and good cosmetic outcome.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

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.

Indications and outcomes of endoscopic transorbital surgery for trigeminal schwannoma based on tumor classification: a multicenter study with 50 cases

OBJECTIVE

Trigeminal schwannoma is a rare CNS tumor and involves the multicompartmental skull base. Recently, the endoscopic transorbital approach (ETOA) has emerged as a technique for minimally invasive surgery. The objective of this study was to evaluate the optimal indications and clinical outcomes of the ETOA for trigeminal schwannomas based on their tumor classification.

METHODS

Between September 2016 and February 2022, the ETOA was performed in 50 patients with trigeminal schwannoma at four tertiary hospitals. There were 15 men and 35 women in the study, with a mean age of 46.9 years. All tumors were classified as type A (predominantly involving the middle cranial fossa), type B (predominantly involving the posterior cranial fossa), type C (dumbbell-shaped tumors involving the middle and posterior fossa), or type D (involvement of the extracranial compartment). Type D tumors were also subclassified by ophthalmic division (D1), maxillary division (D2), and mandibular division (D3). Clinical outcome was analyzed, including extent of resection and surgical morbidities.

RESULTS

In this study, overall gross-total resection (GTR) was performed in 35 (70.0%) of 50 patients and near-total resection (NTR) in 9 patients (18.0%). The mean follow-up period was 21.9 (range 1-61.7) months. There was no tumor regrowth or recurrence during the follow-up period. Based on the classification, there were 17 type A tumors, 20 type C, and 13 type D. There were no type B tumors. Of the 13 type D tumors, 7 were D1, 1 D2, and 5 D3. For type A tumors, GTR or NTR was achieved using an ETOA in 16 (94.1%) of 17 patients. Eighteen (90.0%) of 20 patients with type C tumors attained GTR or NTR. Ten (76.9%) of 13 patients with type D tumors underwent GTR. Statistical analysis showed that there was no significant difference in the extent of resection among the tumor subtypes. Surgical complications included transient partial ptosis (n = 4), permanent ptosis (n = 1), transient diplopia (n = 7), permanent diplopia (n = 1), corneal keratopathy (n = 7), difficulties in mastication (n = 5), and neuralgic pain or paresthesia (n = 14). There were no postoperative CSF leaks or enophthalmos during follow-up.

CONCLUSIONS

This study showed that trigeminal schwannomas can be effectively treated with a minimally invasive ETOA in all tumor types, except those predominantly involving the posterior fossa (type B). For the extracranial compartments, D2 or D3 tumor types often require an ETOA combined with the endoscopic endonasal approach, while D1 tumor types can be treated using an ETOA alone.

Endoscopic transorbital approach for skull base lesions: a report of 16 clinical cases

Due to the deep location, complex anatomy, and adjacent vital neurovascular structures, skull base surgery is challenging and requires specific approaches. The emerging endoscopic transorbital approach (eTOA) technique provides a new approach to the orbital content, spheno-orbital region, lateral cavernous sinus, and Meckel's cave. In this study, the clinical utility and effectiveness of the eTOA are reported. Sixteen cases who underwent the eTOA were included in the current study. The patients were divided into 3 groups according to tumor location: Group A (intraorbital, 6 cases), group B (spheno-orbital, 7 cases), and group C (cavernous sinus, and Meckel's cave, 3 cases). The clinical data and surgical results were analyzed. Eight meningiomas, 2 hemangiomas, 1 low-grade glioma, 1 instance of inflammatory hyperplasia tissue, 1 Langerhans cell histiocytosis, 1 epidermoid cyst, 1 trigeminal schwannoma, and 1 bone fibrosis hyperplasia were observed. The mean tumor diameter was 2.4 cm. A single case in Group A and Group C underwent biopsy (12.5%), and 1 case of fibrous dysplasia in Group B underwent sufficient orbit decompression (6.25%). The remaining 13 cases underwent gross total tumor resection (81.25%). No cerebral-spinal fluid leak or infection occurred. And no cosmetic problems or significant complications were observed during the follow-up. As a minimally invasive technique, the eTOA has unique advantages for carefully selected skull base lesions because of its direct route, short working distance, and distinct attack angle.

Modified Lateral Orbitotomy Approach to Lesions of the Orbital Apex, Superior Orbital Fissure, Cavernous Sinus, and Middle Cranial Fossa

BACKGROUND

The lateral orbitotomy approach (LOA) provides minimally invasive access to the orbit, cavernous sinus region, and middle cranial fossa. Orbital retraction with this approach can nonetheless injure orbital structures, causing unnecessary morbidity.

OBJECTIVE

To describe our clinical experience with the modified LOA (mLOA), wherein the medial aspect of the lateral orbital wall posterior to the orbital rim is preserved.

METHODS

This is a retrospective, single-institution case series of patients undergoing a mLOA for lesions of the orbital apex, superior orbital fissure, cavernous sinus, and middle cranial fossa. The dimensions and variance of selected anatomic parameters relevant to this approach (orbital rim-superior orbital fossa depth, lateral orbital wall angle) were also analyzed using computed tomography scans from 30 adult patients.

RESULTS

Eight patients underwent a mLOA (mean age 54.0 ± 19.6 years; 3 males). Surgical targets included the superior orbital fissure (2; cavernoma and meningioma), sphenoid wing with or without the orbital apex (2; meningioma), cavernous sinus (2; rule out carcinoma and smooth muscle tumor), and anterior/mesial temporal lobe (2; cavernoma). Visual acuity/fields and diplopia was stable or improved in all patients postoperatively. One patient experienced a cerebrospinal fluid leak. On computed tomography analysis, the relevant bony anatomy displayed limited variability, with a mean orbital fossa depth of 42.7 ± 2.8 mm and a lateral orbital wall angle of 44.4° ± 2.7°.

CONCLUSION

The mLOA can provide safe, minimally invasive access to select lesions of the orbital apex, superior orbital fissure, cavernous sinus, and middle cranial fossa. The operative corridor has relatively consistent bony anatomy.

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.

The use of an endoscopic endonasal approach for a secondary intraorbital meningioma: illustrative case

BACKGROUND

Meningiomas are the most frequent primary tumors in the central nervous system (CNS), but intraorbital location is uncommon and accounts for only 0.2% to 4% of all CNS meningiomas. Lesions in this compartment could be classified as primary, secondary, or ectopic. The close relationship with the optic nerve sheath is a landmark to identify the tumor as primary, whereas secondary tumors commonly come from an extension of an intracranial meningioma, and ectopic meningioma is a concept not yet completely established.

OBSERVATIONS

The authors present a rare case of a secondary intraorbital meningioma operated through an endoscopic endonasal approach. Secondary meningiomas at the medial orbit are very uncommon, given their more common superior and lateral location as an extension of sphenoid meningiomas. The endoscopic endonasal route provides direct access to the medial orbit. The authors present an illustrative case of a meningioma located at the medial orbit and resected through an endoscopic endonasal approach that provided excellent visualization and anatomical exposure. Additionally, the authors review the concept and possible similarities between secondary and ectopic intraorbital meningiomas.

LESSONS

An endoscopic endonasal approach should be considered as a feasible treatment option for intraorbital meningiomas, especially if they are in the medial orbital wall.

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.

Combined endoscopic endonasal and transorbital multiportal approach for complex skull base lesions involving multiple compartments

PURPOSE

This study defines the specific areas that connect the surgical corridors of the endoscopic endonasal (EEA) and transorbital approach (TOA) to identify adequate clinical applications and perspectives of this combined multiportal approach.

METHODS

Consecutive patients who underwent combined EEA and TOA procedures for various pathologies involving multiple compartments of the skull base were enrolled.

RESULTS

A total of eight patients (2 chondrosarcomas, 2 meningiomas, 2 schwannomas, 1 glioma, and 1 traumatic optic neuropathy) were included between August 2016 and April 2021. The cavernous sinus (CS) was targeted as the connection area of the combined approach in four patients with tumors infiltrating the middle cranial fossa (MCF) and central skull base through the CS. For two patients with MCF tumors extending into the infratemporal fossa (ITF), the horizontal portion of the greater sphenoid wing and the foramen ovale were utilized as the connection area. In the remaining 2 patients, connection was achieved through the optic canal (OC). Gross total and near total resection was achieved in 5 patients with tumors, and circumferential removal of bone composing the OC was performed in one patient with traumatic compressive optic neuropathy. Postoperative complications included one cardiac arrest due to underlying cardiovascular disease and one case of oculomotor nerve palsy.

CONCLUSIONS

The combined EEA and TOA procedure is a useful strategy for complex lesions involving multiple compartments of the skull base. Herein, we identified the specific areas connecting the two surgical approaches, allowing a common path for EEA and TOA procedures.

Middle cranial fossa trigeminal schwannoma resection through endoscopic transnasal maxillary sinus approach: A case report and literature review

The endoscopic transnasal maxillary sinus approach is usually performed in resecting tumors located in the pterygopalatine fossa and infratemporal fossa, but is rarely used in the resection of lesions in the middle cranial fossa. Because of the complicated anatomical structure of the middle cranial fossa, trigeminal schwannomas (TSs) located in this region are usually dissected through conventional craniotomy surgical approaches; however, the endoscopic transnasal maxillary sinus approach can be used in resection of middle cranial fossa TSs. The current study presented the case of a 59-year-old man who suffered intermittent headaches for 2 years without other notable medical history and neurological abnormalities. The patient was diagnosed with a middle cranial fossa TS. After imaging and assessment of anatomical features, the tumor was totally resected through the transnasal maxillary sinus approach. Following surgery, the symptoms were relieved and the patient returned to a normal life. Light numbness was complained of in the distribution area of the maxillary nerve of the right side of the face, but this was gradually relieved. Combined with a literature review, the present case indicated that the endoscopic transnasal maxillary sinus approach may provide a safer and more direct option for resecting middle cranial fossa lesions, which is worthy of increased clinical application.

Endoscopic sublabial transmaxillary approach to the inferior orbit: pearls and pitfalls-A comparative anatomical study

OBJECTIVE

Although orbital surgery has always represented a challenge for neurosurgeons, keyhole and endoscopic techniques are gradually surging in popularity maximizing functional and esthetic outcomes. This quantitative anatomical study first compared the surgical operability achieved through three endoscopic approaches within the inferior orbit: the endoscopic sublabial transmaxillary (ESTMax), the endoscopic endonasal transethmoidal (EETEth), and the endoscope-assisted lateral orbitotomy (ELO).

METHODS

Each of these approaches was performed bilaterally on five specimens. We described the ESTMax step-by-step, underlining its advantages and pitfalls in comparison with EETEth and ELO. Then, we assessed surgical measurements and operability in ESTMax, EETEth, and ELO.

RESULTS

The ESTMax provided the most favorable operative window (278.9 ± 43.8 mm²; EETEth: 240.8 ± 21.5 mm², p < 0.001; ELO: 263.1 ± 19.8 mm², p = 0.006), the broadest surgical field area (415.9 ± 26.4 mm²; EETEth: 386.7 ± 30.1 mm², p = 0.041; ELO: 305.2 ± 26.3 mm², p < 0.001), surgical field depths significantly shorter than EETEth (p < 0.001) but similar to ELO, the widest surgical angles of attack (45°-65°; EETEth: 20°-30°, p < 0.001; ELO: 25°-50°, p < 0.001), and the greatest surgical mobility areas (EETEth: p < 0.001; ELO: p < 0.001). Furthermore, the ESTMax allowed multi-angled exposure and handy maneuverability around all the inferior intraorbital targets. Small anterior antrostomy, blunt intraorbital dissections, direct targets' approach, orbital floor reconstruction, and maxillary bone flap replacement may limit the ESTMax morbidity rates.

CONCLUSIONS

The ESTMax is a minimally invasive "head-on" orbital approach that exploits endoscopic surgery advantages avoiding the cranio-orbital and trans-nasal approach limitations and possible complications. It represents a promising alternative to EETEth and ELO because of its optimal operability for resecting lesions extending into the entire inferior orbit.