Compartmental endoscopic surgical anatomy of the medial intraconal orbital space

Endoscopic-assisted transorbital extended orbital exenteration: A multi-institutional preclinical study

BACKGROUND

Sinonasal malignancies with orbital invasion have dismal prognosis even when treated with orbital exenteration (OE). Sugawara et al. developed a surgical strategy called "extended-OE (EOE)," showing encouraging outcomes. We hypothesized that a similar resection is achievable under endoscopic guidance through the exenterated orbit (endoscopic-EOE).

METHODS

The study was conducted in three institutions: University of Vienna; Mayo Clinic; University of Insubria; 48 orbital dissections were performed. A questionnaire was developed to evaluate feasibility and safety of each step, scoring from 1 to 10, ("impossible" to "easy," and "high risk" to "low risk," respectively), most likely complication(s) were hypothesized.

RESULTS

The step-by-step technique is thoroughly described. The questionnaire was answered by 25 anterior skull base surgeons from six countries. Mean, median, range, and interquartile range of both feasibility and safety scores are reported.

CONCLUSIONS

Endoscopic-EOE is a challenging but feasible procedure. Clinical validation is required to assess real-life outcomes.

Resection of orbital apex tumours in the medial orbit via four-handed endonasal and transcaruncular approaches

PURPOSE

To report the surgical outcomes of 4-handed endoscopic and transcaruncular approaches for orbital apex tumours located in the medial orbit.

METHODS

This retrospective, observational study included 6 patients (2 males and 4 females; 3 right and 3 left; mean age, 49.5 years; age range, 38-60 years) who underwent excision of an orbital apex tumour in the medial orbit via 4-handed endonasal and transcaruncular approaches. Data on age, sex, affected side, surgical record and complications, and results of pathological examinations, imaging studies, and ophthalmologic examinations were collected.

RESULTS

Tumours pathologically corresponded to a cavernous haemangioma in 5 cases and a schwannoma in 1 case. The cavernous haemangioma was completely removed in all cases, while the schwannoma was only debulked because the tumour attached to the surrounding tissues. The medial orbital wall was reconstructed simultaneously in 1 case and 8 days after tumour resection in 1 case. Postoperatively, the visual acuity improved or was maintained in all patients. One patient without medial orbital wall reconstruction showed significant enophthalmos on the affected side after surgery. Another patient without medial orbital wall reconstruction did not obtain binocular single vision field in any direction of gaze after surgery due to severe esotropia.

CONCLUSIONS

This report indicates that 4-handed endoscopic and transcaruncular approaches are useful for removal of an orbital apex tumour located in the medial orbit. Medial orbital wall reconstruction after tumour resection may be a better option for reducing the risk of postoperative enophthalmos and esotropia.

Modified Function-Preserving Endoscopic Endonasal Extracapsular Resection of a Large Orbital Apex Cavernous Hemangioma

BACKGROUND AND IMPORTANCE

Various invasive oculoplastic procedures are commonly utilized to control the rectus muscles and widen the surgical corridor through the endoscopic endonasal removal of large orbital apex cavernous hemangiomas (OACHs). They require additional transconjunctival incision, rectus muscle insertional retraction, or muscle deinsertion at the globe that might not be safe and lead to prolonged postoperative extraocular muscle dysfunction. In this article, the authors described a modified 3-handed extracapsular technique for the resection of a large OACH without an additional procedure for rectus muscle control. The aim is to achieve a safe gross total tumor removal while minimizing the procedure-related complications. An intraoperative video is included, along with a stepwise cadaveric dissection relevant to the approach.

CLINICAL PRESENTATION

A 71-year-old female presented with progressive left-sided blurred vision, binocular diplopia, and mild proptosis. Contrast-enhanced brain MRI revealed a large heterogeneous enhanced inferomedial intraconal mass in the left orbital apex, mostly consistent with cavernous hemangioma. Gross total tumor removal was achieved through a modified 3-handed endoscopic endonasal extracapsular approach. The diplopia was resolved, and significant visual improvement was achieved. Computed tomography scan demonstrated complete tumor removal, and histological examination confirmed the diagnosis.

CONCLUSION

Endoscopic endonasal resection of large OACH can be feasibly performed by using a modified 3-handed extracapsular technique through the generous use of Q-tip swab applicators within the natural separation plane around the tumor capsule and a sequential traction-countertraction method. Subsequently, a gross total removal and optimal postoperative functional outcome are attainable through minimal rectus muscle fiber violation and intraconal fat manipulation.

Transorbital and endonasal resection of a rare orbital ectopic atypical meningioma

A female patient in her early 20s presented with increasing proptosis of her left eye over 2 months. She had no other signs of diplopia, pain or visual loss on initial presentation. Subsequent imaging of her orbits revealed a medial rectus tumour. A transorbital open biopsy of this tumour was non-diagnostic/inconclusive, hence a combined transorbital and endonasal resection of this tumour was performed. Histopathology of the resected tumour revealed an unusual inflammatory-rich spindle cell neoplasm, which was determined to be a primary orbital ectopic atypical meningioma. These tumours are exceedingly rare, with only case reports/series reported in the literature. Complete surgical resection with margins is the proposed treatment. The role of radiotherapy is still controversial. More studies are required to improve our knowledge of this condition.

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.

Endoscopic Endonasal Approach to Intraconal Orbital Tumors: Outcomes and Lessons Learned

BACKGROUND

Lesions involving the intraconal space of the orbit are rare and challenging to manage. Operative techniques and outcomes for the endoscopic endonasal approach (EEA) to tumors in the medial intraconal space (MIS) remain poorly characterized.

OBJECTIVE

We present our experience with a wide range of isolated intraconal pathology managed via an EEA.

METHODS

A retrospective review of all cases (2014-2021) performed by a single skull base team in which the EEA was employed for the management of an intraconal orbital lesion.

RESULTS

Twenty patients (13 men, 7 women) with a mean age of 59 years (range, 40-89 years) were included. All lesions were isolated to the MIS, pathology addressed included: cavernous hemangioma (6), schwannoma (4), lymphoma (4), inflammatory pseudotumor (2), chronic invasive fungal sinusitis (2), and metastatic disease (2). Either a biopsy (10/20) or a complete resection (10/20) was performed. In all cases, the MIS was accessed via an endonasal corridor between the medial and inferior rectus muscles. Retraction and safe, intra-orbital dissection of the lesion was performed using a two-surgeon, multi-handed technique. Gross total resection of benign lesions was achieved in 90% (9/10) of cases; a pathologic diagnosis was achieved in 100% (10/10) of biopsy cases. No orbital reconstruction was required. Visual acuity returned to normal in 80% (8/10) of planned resection cases and postoperative diplopia resolved by 3 months in 90%. Mean follow-up was 15 months.

CONCLUSION

This study demonstrates that the EEA is safe and effective for accessing lesions in the MIS. This technique affords very favorable outcomes with minimal postoperative morbidity.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:47-55, 2024.

Through the orbit and beyond: Current state and future perspectives in endoscopic orbital surgery on behalf of the EANS frontiers committee in orbital tumors and the EANS skull base section

Introduction

Orbital surgery has always been disputed among specialists, mainly neurosurgeons, otorhinolaryngologists, maxillofacial surgeons and ophthalmologists. The orbit is a borderland between intra- and extracranial compartments; Krönlein's lateral orbitotomy and the orbitozygomatic infratemporal approach are the historical milestones of modern orbital-cranial surgery.

Research question

Since its first implementation, endoscopy has significantly impacted neurosurgery, changing perspectives and approaches to the skull base. Since its first application in 2009, transorbital endoscopic surgery opened the way for new surgical scenario, previously feasible only with extensive tissue dissection.

Material and methods

A PRISMA based literature search was performed to select the most relevant papers on the topic.

Results

Here, we provide a narrative review on the current state and future trends in endoscopic orbital surgery.

Discussion and conclusion

This manuscript is a joint effort of the EANS frontiers committee in orbital tumors and the EANS skull base section.

Morphometric Analysis of the Ophthalmic and Central Retinal Arteries via the Endoscopic Endonasal Trans-ethmoidal Approach: Surgical Relevance of Vascular Components Within the Medial Intraconal Zones

BACKGROUND

The endoscopic endonasal approach (EEA) offers a minimally invasive route to treat medial intraconal space (MIS) lesions. Understanding the configuration of the ophthalmic artery (OphA) and the central retinal artery (CRA) is crucial.

METHODS

An EEA to the MIS was performed on 30 orbits. The description of the intraorbital part of the OphA was divided into 3 segments and classified as type 1 and type 2 and the MIS was divided into three surgical zones (A, B, C). The CRA's origin, course, and point of penetration (PP) were analyzed. The relationship between the position of the CRA in the MIS and the OphA type was analyzed.

RESULTS

The OphA type 2 was present in 20% of specimens. The site of origin of the CRA from the OphA was found on the medial surface in type 1 and on the lateral surface of type 2. The point of penetrationof the central retinal arterywas found in 87% of the specimens on the inferomedial surface, just anterior to the inferior muscular trunk, at an average distance of 9.5 mm ± 1 from the globe and 17 mm ± 1.5 from the AZ. The presence of the CRA in Zone C was associated only with OphA type 1.

CONCLUSIONS

OphA type 2 is a common finding and can compromise the feasibility of an EEA to the MIS. A detailed preoperative analysis of the OphA and CRA should be conducted prior to approaching the MIS due to the implications of the anatomical variations that can compromise safe intraconal maneuverability during an EEA.

Comparative endoscopic techniques of medial rectus muscle retraction for approaching intraconal tumors: Our experience with five cases

Objective

To examine the role of transnasal endoscopic approaches in the management of intraconal tumors and demonstrate the use of an eyelid speculum in comparison with different techniques of medial rectus muscle (MRM) retraction.

Methods

Retrospective data of five patients with intraconal tumors operated on and followed up by the senior authors between December 2019 and April 2022 was collected. Presenting symptoms, technical details, imaging and histology findings, outcomes, and complications were evaluated.

Results

Four primary and one recurrent tumor were identified. The mean patient age was 50 (range, 29–64) years. One tumor was located lateral to the optic nerve, one central and three medial. A complete surgical resection was obtained in four primary cases and a partial resection was achieved in the recurrent case. The MRM was retracted using three different techniques: (1) an infant eyelid speculum creating an operative window between the medial and inferior rectus muscle, (2) external MRM disinsertion transconjunctivally, (3) a four-handed technique performed transseptally by two surgeons. Transient postoperative ophthalmoplegia was recorded in four cases and transient ptosis in one. Three patients completely recovered in 2–3 months while one undergoing MRM disinsertion ended up in restricted strabismus at 15-month follow-up. No other long-term complications have been noted in all five patients with a mean follow-up of 22 (range, 14–32) months. No patients with primary tumors have required additional surgery for tumor recurrence.

Conclusion

The indication of endoscopic intraconal surgery may expand to lesions lateral to the optic nerve when the nerve is not in its natural position. The well-known advantages of the endoscopic techniques, namely the lack of external scars, better visualization, less bleeding, and fewer complications, were confirmed. An eye speculum provides a better surgical corridor and eases the pressure exerted on the MRM, which has a promising application prospect.

Removal of Small Cavernous Hemangioma in Orbital Apex Through an Endoscopic Transethmoidal-Sphenoidal Approach

OBJECTIVE

To investigate the feasibility, efficacy, and safety of an endoscopic transethmoidal-sphenoidal approach in removing a small cavernous hemangioma (CH) located in the deep lateral orbital apex.

METHODS

This study involved 19 patients diagnosed with a CH located in the deep lateral orbital apex. All patients underwent an endoscopic transethmoidal-sphenoidal approach for removal of the CH. The best-corrected visual acuity (BCVA), visual field, and surgery-related complications were analyzed and compared.

RESULTS

All tumors in this study were completely removed. The mean BCVA was LogMAR 0.97 ± 0.97 preoperatively and LogMAR 0.38 ± 0.64 postoperatively (p < 0.05). The mean visual field index was 52.26% ± 33.26% preoperatively and 75.47% ± 30.49% postoperatively (p < 0.05). The mean deviation index was -17.48 ± 12.43 dB preoperatively and -10.10 ± 10.85 dB postoperatively (p < 0.05), and the pattern standard deviation was 6.37 ± 3.77 dB preoperatively and 4.90 ± 3.56 dB postoperatively (p > 0.05). Four (21.1%) patients developed oculomotor limitations and two (10.5%) patients developed ptosis after surgery. All of these symptoms resolved spontaneously, and no other complications occurred. The mean follow-up time was 6.71 ± 3.89 months.

CONCLUSION

The endoscopic transethmoidal-sphenoidal approach is an effective and minimally invasive treatment for removing small CH in the deep lateral orbital apex.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2022.

Endoscopic surgery for intraconal orbital tumors

Traditionally, external craniofacial approaches have been used for orbital tumor resection. Over the last 30 years, endoscopic sinonasal and skull base techniques have become widely used throughout the world. These experiences paved the way for the extension of transnasal endoscopic techniques to the intraconal orbit. Transnasal endoscopic intraconal surgery has several advantages regarding morbidity and outcome as compared with purely external approaches. However, the anatomical knowledge and experience of the surgeon is crucial for the success of the surgery. Endoscopic approaches for intraconal tumor removal are feasible for medial and inferior lesions as well as for lesions lateral to the optic nerve provided they remain inferior to the "plane of resectability" and no optic nerve retraction is required. As intraorbital tumors are rare, new international staging systems including CHEER (Cavernous Hemangioma Exclusively Endonasal Resection) and ORBIT (Orbital Resection by Intranasal Technique) help to standardize safety, efficacy, and outcome.

How I do it: endoscopic endonasal approach to the orbital apex

BACKGROUND

The endoscopic endonasal approach provides an option to approach the medial and inferior orbital apex, with less manipulation of intraorbital structures.

METHOD

We described the advantages, complications, caveats, and indications of the endoscopic endonasal approach to the orbital apex. An intraorbital extraconal cavernous malformation is shown as example.

CONCLUSION

The endoscopic endonasal approach is a good corridor to the medial and inferior orbital apex, providing good exposure and little manipulation of the intraorbital contents.

Endoscopic endonasal resection of orbital schwannoma assisted with small-incision medial orbitotomy: case series and surgical technique

PURPOSE

To describe a surgical approach for the resection of schwannomas occurring in the medial aspect of the orbit and to review a series of patients who underwent this novel technique.

METHODS

This retrospective, non-comparative case series presents the surgical technique and outcomes of patients who underwent removal of a medial orbital schwannoma via an endoscopic endonasal approach combined with a small-incision medial orbitotomy by a team of two surgeons (BSB and SKF). Patient demographics, pre- and post-operative clinical examination findings, visual field testing, and radiographic studies were reviewed. Operative reports were reviewed for technical details and complications.

RESULTS

The patients included a 12 year-old male, 73 year-old female and 8 year-old male. Indications for surgery included: decreased visual acuity, diplopia, proptosis and Humphrey visual field (HVF) deficit, in the presence of a medial orbital biopsy-proven schwannoma. The surgical approach in all three patients was primarily endoscopic endonasal. Additionally, two had transcaruncular orbitotomies and one had a small-incision medial lid crease orbitotomy to assist with lateral tumor dissection. Tumor resection was complete in one case and near-total in two cases. There were no intra-operative surgical complications. Average resected specimen volume was 3.41 cm³ ± 2.20. All patients had post-operative improvement in visual acuity (VA) and proptosis. Post-operative follow-up intervals were 27.5 months, 12.3 months and 3.5 months, respectively.

CONCLUSION

Resection of orbital schwannomas using an endoscopic endonasal approach with small-incision medial transorbital assistance is a safe and effective option for a multidisciplinary surgical team.

Endonasal resection of orbital cavernous venous malformations with septal preservation

PURPOSE

Multiple surgical approaches have been described to maximize visualization and accessibility for resection while minimizing morbidity in the patient with orbital intraconal tumors. Transnasal endoscopic approaches have become increasingly standard in select orbital cavernous venous malformations but often require a partial septectomy. The purpose of this manuscript is to communicate a septal preserving modified transseptal approach.

METHODS

A 37-year old male was found to have an inferomedial intraconal orbital mass, measuring up to 2.6 cm on magnetic resonance imaging. Binarial transseptal access with septal preservation was obtained with a Killian incision on the right and a small incision in the midseptum on the left.

RESULTS

Successful tumor delivery through the nasal cavity resulted in orbital relaxation. Postoperative evaluation of the septum demonstrated an intact septum with nearly no evidence of septal trauma from surgical manipulation.

CONCLUSION

This technique is easily performed and affords adequate visualization and freedom of movement as traditional binarial transseptal approaches without the disadvantages of partial septal loss such as increased crusting, olfactory disturbance, and loss of nasoseptal flaps.

The Endoscopic Transnasal Approach to Orbital Tumors: A Review

Historically, surgical access to orbital tumors has required a transcutaneous, transconjunctival or transcranial approach. Resection of orbital tumors is notoriously challenging due to the surrounding dense network of critical structures in a confined bony cavity. Advances in endoscopic endonasal surgery, initially used for sinonasal and skull base conditions, have allowed for expansion of its applications beyond the sinorbital interface. In the past decade, the evolution of techniques has enabled a purely endoscopic, minimally invasive approach to medially located orbital pathology with good outcomes. With experience and multidisciplinary collaboration between orbit and rhinologic surgeons, this has expanded to allow for a safe and effective transnasal approach to nearly all regions of the orbit with or without assistance from the orbital side. This review summarizes the relevant anatomy, variations of surgical approaches, and literature regarding outcomes of the endoscopic endonasal approach to orbital tumors.

A systematic review of the surgical anatomy of the orbital apex

PURPOSE

The orbital apex is the narrowest part of the orbit, housing the link between the intracranial cavity and orbit. Knowledge of orbital apex anatomy is crucial to selecting a surgical approach and reducing the risk of complications. Our purpose is to summarize current knowledge on surgical anatomy and attempt to reach a consensus on definition of the orbital apex.

METHODS

The online databases of Embase, the Cochrane library, Web of Science and PubMed (MEDLINE) were queried in a comprehensive bibliographic search on the (surgical) anatomy of the orbital apex and consisted of a combination of two subjects, using indexed terms and free text: "Orbital Apex" and "Orbital Anatomy."

RESULTS

A total of 114 relevant papers were included in this review. Numerous anatomical variations are described in the literature. Variations of the optic canal include duplication (0.64%) and keyhole anomaly (2.65%). Variations in pneumatization of the anterior clinoid process were unilateral in almost 10%, bilateral in 9%, and normal in 72%. A rare variant of the superior orbital fissure (SOF) is Warwick's foramen, which appears as if the lowest portion of the SOF was separated from the main fissure by a transverse bony bridge.

CONCLUSION

The definition of the orbital apex varies in the literature, and further research would most likely identify additional variations. A universal definition reporting these variations and pathology and imaging findings is essential for determining the optimal surgical approach to the orbital apex.

Radioanatomic Characteristics of the Posteromedial Intraconal Space: Implications for Endoscopic Resection of Orbital Lesions

BACKGROUND AND PURPOSE

Imaging is essential in the diagnostic work-up of patients with orbital lesions. The position of an orbital lesion relative to the inferomedial muscular trunk of the ophthalmic artery determines endoscopic resectability, anticipated technical difficulty, and patient morbidity. Although the inferomedial muscular trunk is not readily identifiable on preoperative imaging, we hypothesize that it is spatially approximate to the location where the ophthalmic artery crosses the optic nerve. Our aim was to determine whether the ophthalmic artery-optic nerve crosspoint anatomically approximates the inferomedial muscular trunk in a cadaver study and can be appreciated on imaging of known posteromedial orbital lesions.

MATERIALS AND METHODS

Dissection was performed on 17 fresh-frozen cadaver orbits to assess the relationship between the inferomedial muscular trunk and ophthalmic artery-optic nerve crosspoint. Retrospective review of imaging in 9 patients with posteromedial orbital lesions assessed posteromedial orbital compartment characteristics and the ability to locate the ophthalmic artery-optic nerve crosspoint.

RESULTS

In our cadaver study, the mean distance between the ophthalmic artery-optic nerve crosspoint and the inferomedial muscular trunk was 1.21 ± 0.64 mm. Retrospectively, the ophthalmic artery-optic nerve crosspoint was identifiable in 9/9 patients, whereas the inferomedial muscular trunk was not identifiable in any patient. Total or partial effacement of the posteromedial intraconal fat triangle was observed in 9/9 patients.

CONCLUSIONS

This study of neurovascular relationships within the posteromedial orbit demonstrates that the ophthalmic artery-optic nerve crosspoint closely approximates the inferomedial muscular trunk and can be seen in patients with posteromedial orbital lesions. Posteromedial intraconal fat effacement may help to localize these lesions. These findings may facilitate multidisciplinary communication and help predict lesion resectability and patient outcomes.

Surgery around the Orbit: How to Select an Approach

Orbital region pathologies may be safely and effectively treated through a various number of approaches. As the concept of "outcome" and minimally invasive surgery keeps gaining popularity in neurosurgery, these approaches-each with specific indications and limitations-together provide the best surgical options.

Endoscopic Endonasal Approach for Intra- and Extraconal Orbital Pathologies

Endoscopic endonasal approaches offer an important alternative in the management of posterior inferomedial orbital pathology. Beginning with endoscopic orbital decompressions for Graves' disease, the endonasal corridor for the management of intra- and extraconal pathologies has continued to evolve. Endonasal removal of orbital cavernous hemangiomas is well described in the literature; however, many other benign and malignant pathologies of the medial orbit can be accessed through this approach. Advantages of the endonasal approach include improved visualization and decreased manipulation of orbital contents in the medial and posterior orbit. Additionally, for tumors that extend from the paranasal sinuses into the orbit, this corridor may be ideal for concurrent management. The current literature for this approach will be reviewed including the oncologic results, complications, limitations, and reconstructive needs along with pertinent anatomy. In addition, data from our own institution will be reviewed.

Expanded exposure and detailed anatomic analysis of the superior orbital fissure: Implications for endonasal and transorbital approaches

This study aimed to ascertain the maximal exposure of the superior orbital fissure (SOF) afforded by combining endonasal and transorbital endoscopic approaches. Six cadaveric specimens (12 sides) were dissected using endonasal and transorbital endoscopic approaches to access the SOF. The order of the approaches was alternated in each specimen (eg, starting with an endonasal approach in one side followed by a transorbital exposure and reversing the order on the contralateral side). Maximal exposure of the SOF and its contents for individual and combined approaches were explored. The endonasal corridor provided adequate access to the inferomedial 1/3 of the SOF and including the proximal segments of cranial nerves (CN) III, V₁ and VI. A transorbital approach was superior accessing the superolateral 2/3's of the SOF, including the superior ophthalmic vein, lacrimal nerve, and distal segment of the CN VI at the lateral aspect; the nasociliary nerve and divisions of CN III centrally; and the frontal nerve and CN IV at the dorsal aspect of levator palpebrae superioris. This study suggests that a combined endonasal and transorbital exposure of the SOF may be advantageous to address lesions in this challenging region.

Endoscopic Endonasal Approaches to the Medial Intraconal Space: Comparison of Transethmoidal and Prelacrimal Corridors

BACKGROUND

Endoscopic transethmoidal and prelacrimal approaches can access the medial intraconal space (MIS).

OBJECTIVE

This study aimed to compare advantages and drawbacks of these two approaches, and to explore their appropriate indications for management of lesions at various locations within the MIS.

METHODS

Six injected cadaveric specimens were dissected using an endonasal approach performing a transethmoidal approach on one side and a prelacrimal approach on the contralateral side. The MIS was divided into three Zones: Zone 1 was defined as the area above the superior border of the medial rectus muscle (MRM), Zone 2 as the area between the MRM and the optic nerve, and Zone 3 as the area below the inferior border of MRM. The exposure provided by these two approaches to various Zones within the MIS was assessed and compared.

RESULTS

The average height of Zone 1 to 3 was 10.35 ± 0.45 mm, 11.07 ± 0.59 mm, and 6.53 ± 0.59 mm, respectively. Both approaches provided adequate exposure of Zone 2 and 3; however, the prelacrimal approach provided direct exposure of the posterosuperior aspect of Zone 2 without retraction of MRM. Retraction of MRM was unavoidable using a transethmoidal approach to enhance further exposure. Access to Zone 1 was adequately achieved through the corridor between superior oblique muscle and MRM via a transethmoidal corridor.

CONCLUSION

Conceptualizing the MIS into the three aforementioned Zones seems beneficial to select the optimal approach for lesions restricted to each specific Zone. Both the transethmoidal and prelacrimal approaches provide adequate exposure for select lesions in the MIS.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Intraconal Anatomy of the Anterior Ethmoidal Neurovascular Bundle: Implications for Surgery in the Superomedial Orbit

Background

The anterior ethmoidal artery (AEA) branches from the ophthalmic artery in the superomedial intraconal space. The feasibility of management of lesions arising from the superomedial intraconal space via an endoscopic endonasal approach has not been sufficiently explored.

Objective

To yield a detailed anatomic description of the anterior ethmoidal neurovascular bundle and its variants to serve as the foundation for possible management of lesions in the superomedial intraconal space.

Methods

Eight cadaveric specimens (16 sides) were dissected using an endonasal approach, tracing the AEA proximally through the superomedial intraconal space. Furthermore, the anatomy of adjacent structures was noted, and distances from the anterior ethmoidal foramen to the origin of the AEA at the ophthalmic artery were measured.

Results

Supraorbital cells were found in 13/16 sides (81.25%), and a bony dehiscence of the anterior ethmoidal canal was observed in 5/16 sides (31.25%). The nasociliary nerve, ophthalmic artery, superior division of the oculomotor nerve, superior rectus muscle, and levator palpebrae superioris were routinely identified in the superomedial intraconal space. The AEA passed through a corridor between the medial rectus and superior oblique muscles after arising from the ophthalmic artery (lateral to the foramen) in all specimens. The average distance from its origin to the anterior ethmoidal foramen was 5.19 ± 0.98 mm.

Conclusion

Anatomically, it is feasible to access the superomedial intraconal space via an endoscopic endonasal approach. This study provides the anatomical basis for procedures in the superomedial intraconal space.

Management of Orbital Masses: Outcomes of Endoscopic and Combined Approaches With No Orbital Reconstruction

Introduction

The endoscopic endonasal approach to management of orbital pathology has expanded. Due to the rarity of these conditions, most reports in the literature consist of small case reports. We report a series from a single institution with a focus on outcomes.

Methods

A retrospective chart review was carried out between 2010 and 2018.

Results

Twenty-four patients were identified (average age 58 years, 15 males, 9 females). Average follow-up was 14.9 months. Most common etiologies included cavernous hemangioma (7), metastases (6), idiopathic orbital inflammatory syndrome (6), orbital hematoma/clot (2), and schwannoma (1). Most common presenting symptoms were decreased visual acuity (8), proptosis (8), diplopia (7), and incidental findings (2). All patients underwent endoscopic medial wall orbital decompressions. Sixteen involved a combined open approach by an ophthalmologist. Pathology was either biopsied (15), resected (6), or could not be identified (3). No intraoperative complications were noted. No patients underwent orbital reconstruction of the medial wall. Six patients developed postoperative sinusitis successfully managed with antibiotics. One patient developed epistaxis managed conservatively. In 5 patients, Sino-Nasal Outcome Test-22 scores increased immediately postop and then decreased, whereas scores only decreased in 6 patients. Six patients noted reduced proptosis. There were no new cases of diplopia or worsening visual acuity.

Conclusions

A combined endoscopic endonasal and external approach can be useful for managing orbital lesions. Patients tolerated the procedure well with improvement in ocular symptoms and minimal sinonasal complications. Reconstruction of the medial wall may not be warranted to prevent postoperative diplopia.

Endoscopic approaches to orbital lesions: case series and systematic literature review

OBJECTIVE

Surgical treatment of orbital lesions is challenging because complex approaches with a high risk of postoperative sequelae are required. Recently, minimally invasive endoscopic approaches through endonasal (EEA) and transpalpebral (ETP) routes have been proposed. The objective of this study was to assess outcomes of EEA and ETP in the authors' series of patients with orbital lesions.

METHODS

Data from all patients who underwent operations for an orbital tumor through an endoscopic approach at the authors' institution from 2002 to 2018 were retrospectively collected. All patients underwent preoperative MRI and ophthalmological evaluation, which was repeated 3 months after surgery and then at regular follow-up intervals. A systematic review of the literature was also performed using Medline, Embase, and Web of Science databases.

RESULTS

The series includes 23 patients (14 males); the mean patient age was 48 ± 23.9 years. Most of the lesions were intraconal (n = 19, 83%). The more frequent histotype was cavernous hemangioma (n = 5, 22%). Exophthalmos was the most common symptom (21 of 23 patients). EEA was performed in 16 cases (70%) and ETP in 7 (30%). The aim of the surgery was achieved in 94% of the cases after an EEA (successful biopsy in 5 of 6 cases and radical resection in all 10 remaining patients), and in 86% after an ETP (successful biopsy in 2 cases and radical tumor resection in 4 of 5 cases). Complications consisted of 3 cases (13%) of transitory diplopia. One recurrence (4%) was observed at follow-up (mean 59 ± 55 months).

CONCLUSIONS

The EEA and ETP have demonstrated to be safe and effective for tumors located respectively in medial and lateral quadrants, permitting one to approach orbital lesions endoscopically at 360°. Innovative surgical tools, including intraoperative ultrasonography, may be useful to potentially reduce surgical morbidity. Larger series are needed to validate these preliminary suggestions.

Endoscopic endonasal intraconal orbit surgery

Endoscopic endonasal orbital surgery is evolving. With increasing knowledge, expertise, and technology, the historical limits of the endonasal endoscopic approach to the orbit have been redefined. This review discusses the clinical presentation and etiology, and highlights the pertinent anatomy, and discusses the diagnostic workup and surgical approach to orbital tumors and post-operative care. The role of the multidisciplinary team is not to be underestimated. The introduction of a classification system to ensure standardization of technical difficulty and outcome data will assist with international collaboration and further consolidate our attainment of knowledge in this developing field.

Development of a Modular Cadaveric Endoscopic Orbital Surgery Model

Introduction

Endoscopic orbital surgery requires the acquisition of unique skill set including endoscopic bimanual dissection of intra/extraconal lesions adherent to orbital fat and neurovascular structures. Our goal was to develop a modular cadaveric model used to train surgeons to resect orbital pathology within any desired orbital compartment.

Methods

Expansile superabsorbent polymer (SAP) beads (2 mm) were soaked in Omnipaque™ (Iohexol) solution for 15 minutes prior to transcaruncular orbital implantation using 10-gauge angiocath. Insertion depth was designed to implant beads in predetermined intraconal compartments corresponding to established orbital tumor stages. Beads were left to expand in situ over a period of 1 to 5 hours. Computed tomography scans were performed using the FUSION image guidance protocol. Model utility and learning curves were assessed by quantifying resection time over 8 sequential attempts.

Results

All 24 beads were successfully implanted in 8 orbits corresponding to CHEER stage II to IV lesions (n = 3 per orbit). Beads expanded from 2 mm to an average of 5.2 mm within 1 hour. During expansion, the beads interpolated into the adjacent fascia similar to in vivo tumors. Average insertion time was 5:53 minutes per orbit (range, 3:24–10:33 min) and average time to bead identification was 10:47 minutes. Across all beads, dissection times decreased in a nonsignificant manner over 8 consecutive attempts.

Conclusion

The directed implantation of expansile SAP beads in this cadaveric model accurately replicates the approach, identification, and resection of isolated orbital lesions. This orbital model can assist the endoscopic surgical team to develop further knowledge and technical skill sets to approach orbital lesions. Further ongoing studies to validate this model are currently underway.

Transnasal endoscopic resection of orbital cavernous hemangiomas: our experience with 23 cases

BACKGROUND

The aim of this work was to present our single-center experience on orbital cavernous hemangiomas managed using an endonasal endoscopic approach.

METHODS

The study design used was one-institutional retrospective review. Twenty-three cases of orbital cavernous hemangioma were analyzed and followed up.

RESULTS

There were 10 males and 13 females, with an average age of 46.1 years, included in our study. Seven cases were extraconal, 16 cases were intraconal, and in 10 of the patients the optic nerve was involved and compressed. Total resection of the tumor was achieved in 16 cases; of the remaining 7 cases, partial tumor resection and orbital decompression were conducted, orbital decompression was conducted in 2 cases, and orbital decompression and optic nerve decompression were conducted in 3 cases. Visual acuity in 9 patients improved significantly, as 16 of the 20 patients with a preoperative visual field defect had a smaller defect after surgery.

CONCLUSION

This study adds to the literature showing that endoscopic transnasal surgery is likely a reasonable option for patients with the orbital cavernous hemangiomas medial of the optic nerve. With greater experience, skilled surgical technique, and careful operation, better clinical efficacy can be achieved.

Relationship of the Optic Nerve to the Medial Rectus Muscle During Endonasal Dissection of the Medial Intraconal Orbital Apex

BACKGROUND

Few studies have established surgical landmarks for endoscopic endonasal dissection of the intraconal orbital apex (OA).

OBJECTIVE

We describe the optic nerve (ON) anatomy and its relationships, as seen during a fully endoscopic, endonasal approach to the medial intraconal OA.

METHODS

The study question was approached through a cadaver dissection and a radiographic study. Four formalin-fixed, latex-injected cadaver heads were dissected using transnasal endoscopic techniques. Dissection was performed using 0 degree and 30 degree nasal endoscopes and standard endoscopic sinus surgical instrumentation. A bi-nostril 4-handed technique was used. The anatomy of 8 medial OAs was evaluated and recorded. As the radiographic portion, 100 consecutively enrolled patient magnetic resonance images were evaluated, with particular attention given to the relationship of the ON to the medial rectus muscle (MRM) in 200 orbits.

RESULTS

Intraconally, the ON consistently coursed along the superior half of the MRM. Interestingly, the nerve was more easily identified from a superior approach after retracting the MRM inferiorly. With the identification of the nerve at the OA, carrying the dissection of the medial OA was easily accomplished with the ON as the guiding landmark. The radiographic portion of this study revealed a consistent relationship between the superior edge of the ON and the MRM. This relationship was maintained in the orbital apex in 98.4%-100% of the orbits examined.

CONCLUSION

The superior edge of the optic nerve is consistently found coursing along the superior half of the MRM, facilitating facile identification and further dissection navigation.

Transnasal prelacrimal approach to the inferior intraconal space: a feasibility study

BACKGROUND

Endonasal access to the inferomedial and inferolateral intraconal space via the orbital floor has not been reported. The primary purpose of this study was to assess the feasibility of accessing the inferior intraconal space through the orbital floor via a transnasal prelacrimal approach. Secondarily, it aims to highlight anatomical relationships of neurovascular structures in this space, as a requirement to prevent complications.

METHODS

Six cadaveric heads (12 sides) were dissected using a transnasal prelacrimal approach. The orbital floor, medial to the infraorbital canal, was removed and the periorbita opened to expose the inferior rectus muscle. The inferomedial and inferolateral intraconal space was accessed alongside the medial and lateral border of inferior rectus muscle, respectively. Various anatomical relationships of adjacent neurovascular structures were recorded, and the distances among the recti muscles and optic nerve were also measured.

RESULTS

The infraorbital nerve is located at the inferolateral aspect of inferior rectus muscle. In the inferomedial intraconal space, we identified the inferomedial muscular trunk of the ophthalmic artery, optic nerve, and branches of the oculomotor nerve; whereas the inferolateral intraconal space contained the inferolateral muscular trunk of ophthalmic artery, branches of the oculomotor and nasociliary nerve, and abducens nerve. Distances from the medial, inferior, and lateral recti muscles to the optic nerve were (mean ± standard deviation) 4.70 ± 1.18 mm, 5.60 ± 0.93 mm, and 7.98 ± 1.99 mm, respectively. Distances from the inferior rectus muscle to the inferior borders of medial and lateral recti muscles were 4.45 ± 1.23 mm and 8.77 ± 1.80 mm.

CONCLUSION

It is feasible to access the inferior intraconal space through the orbital floor via a transnasal prelacrimal approach. The access may be subdivided into inferomedial and inferolateral corridors according to the entry point at the medial or lateral border of the inferior rectus muscle. Neurovascular structures in the inferior intraconal space are visualized directly, which should enhance their preservation.

Expanding the limits of endoscopic intraorbital tumor resection using 3-dimensional reconstruction

Introduction

Endoscopic orbital surgery is a nascent field and new tools are required to assist with surgical planning and to ascertain the limits of the tumor resectability.

Objective

We purpose to utilize three-dimensional radiographic reconstruction to define the theoretical lateral limit of endoscopic resectability of primary orbital tumors and to apply these boundary conditions to surgical cases.

Methods

A three-dimensional orbital model was rendered in 4 representative patients presenting with primary orbital tumors using OsiriX open source imaging software. A 2-Dimensional plane was propagated between the contralateral nare and a line tangential to the long axis of the optic nerve reflecting the trajectory of a trans-septal approach. Any tumor volume falling medial to the optic nerve and/or within the space inferior to this plane of resectability was considered theoretically resectable regardless of how far it extended lateral to the optic nerve as nerve retraction would be unnecessary. Actual tumor volumes were then superimposed over this plan and correlated with surgical outcomes.

Results

Among the 4 lesions analyzed, two were fully medial to the optic nerve, one extended lateral to the optic nerve but remained inferior to the plane of resectability, and one extended both lateral to the optic nerve and superior to the plane of resectability. As predicted by the three-dimensional modeling, a complete resection was achieved in all lesions except one that transgressed the plane of resectability. No new diplopia or vision loss was observed in any patient.

Conclusion

Three-dimensional reconstruction enhances preoperative planning for endoscopic orbital surgery. Tumors that extend lateral to the optic nerve may still be candidates for a purely endoscopic resection as long as they do not extend above the plane of resectability described herein.

Development of the international orbital Cavernous Hemangioma Exclusively Endonasal Resection (CHEER) staging system

BACKGROUND

Orbital cavernous hemangiomas (OCH) are the most common adult orbital tumor and represent an ideal index lesion for endonasal orbital tumor surgery. In order to standardize outcomes reporting, an anatomic-based staging system was developed.

METHODS

An international, multidisciplinary panel of 23 experts in orbital tumor surgery was formed. A modified Delphi method was used to develop the cavernous hemangioma exclusively endonasal resection (CHEER) staging system with a total of 2 rounds being completed.

RESULTS

Tumors medial to a plane along the long axis of the optic nerve may be considered amenable for an exclusively endonasal resection. In select cases, tumors may extend inferolaterally if the tumor remains below a plane from the contralateral naris through the long axis of the optic nerve (ie, plane of resectability [POR]). This definition reached consensus with 91.3% of panelists in agreement. Five stages were designed based on increasing technical resection difficulty and potential for morbidity. Stages were based on the relationship of the tumor to the extraocular muscles, the inferomedial muscular trunk of the ophthalmic artery (IMT), and orbital foramina. Staging by anatomic location also reached consensus with 87.0% of panelists in agreement. Size was not included in the staging system due to the lack of agreement on the contribution of size to resection difficulty.

CONCLUSION

Endoscopic orbital tumor surgery is a nascent field with a growing, yet heterogeneous, body of literature. The CHEER staging system is designed to facilitate international, high-quality, standardized studies establishing the safety, efficacy, and outcomes of endonasal resection of OCH.

Analysis of anterior and posterior maneuvers to enhance intraconal exposure

BACKGROUND

The medial and inferior recti encompass the ideal surgical corridor to approach the intraconal space endonasally. Here, we describe 3 different maneuvers to achieve greater access to orbital contents through an expanded endonasal approach (EEA).

METHODS

Four human cadaver heads were dissected bilaterally (n = 8). EEA to the medial intraconal orbit was executed. The following 3 maneuvers were performed: (1) anterior: extraocular muscles control (EOM); (2) posterior: annulus of Zinn (AZ) release; and (3) anterior/posterior combined. Measurements of the inferior and medial rectus corridor at the level of anterior ethmoidal artery (AEA) and posterior ethmoidal artery (PEA) and extent of optic nerve and medial rectus visualization was performed before and after each maneuver.

RESULTS

Medial rectus length (MRL) and optic nerve length (ONL) achieved were 1.72 ± 0.28 cm and 0.85 ± 0.2 cm, respectively. Mean caudal-rostral distances between the rectus muscles at the level of the AEA and PEA were 3.45 ± 0.7 mm and 1.30 ± 0.3 mm, respectively. After EOM control, mean caudal-rostral distances at the same level were as follows: AEA 4.90 ± 1.15 mm (p = 0.009) and PEA 1.70 ± 0.20 mm (p = 0.016). With AZ release, MRL was 2.20 ± 0.7 cm (p = 0.002) and ONL was 1.30 ± 0.2 cm (p = 0.003), with mean rostral-caudal distance at the level of AEA at 4.03 ± 0.8 mm (p = 0.16) and PEA at 1.71 ± 0.36 mm (p = 0.039). Mean caudal-rostral distances achieved with AZ release and EOM control were as follows: AEA 5.6 ± 1.2 mm (p = 0.001) and PEA 2.15 ± 0.4 mm (p = 0.001).

CONCLUSION

Progressive access to the orbital contents is afforded with the 3 delineated maneuvers. The magnitude of access is optimized with the combined maneuver. The actual anterior/posterior location of the target will determine which maneuvers are required.

Compartmental Endoscopic Surgical Anatomy of the Inferior Intraconal Orbital Space

Objectives  This study aims to define the endoscopic anatomy of inferior intraconal space, in terms of its neurovascular structures and relationship to fixed anatomic landmarks. Design  A cadaveric anatomical study was conducted. Setting  This study was conducted at an academic cranial base center. Participants  Cadaveric subjects have been investigated. Main Outcome Measures  After dissection of the inferior intraconal space, the number and position of ophthalmic artery (OA) and oculomotor nerve (OMN) branches to the inferior rectus muscle (IRM) were quantified relative to the fixed landmark of the posterior maxillary wall. The point where the OMN branch to the inferior oblique muscle (IOM) crossed the lateral IRM margin was quantified. Results  A total of 18 OA branches were identified with a mean ± standard deviation of 2.6 ± 0.53 branches. The mean distance of the OA branch insertion from the posterior maxillary wall was 7.11 ± 5.65 mm. The average number of OMN branches to the IRM was 1.63 ± 0.74 with a mean insertion distance of 1.88 ± 1.89 mm. The OMN branch to the IOM crossed the lateral IRM margin 5.38 ± 5.42 mm from the posterior maxillary wall. Conclusions  This cadaveric study quantifies the variability of two critical neurovascular structures salient to endoscopic approaches to the inferior intraconal space, the OMN, and OA contributions to the IRM. Knowledge of the interrelationship between these structures is essential in safe technique for dissection.

Surgical Management of Severe Epistaxis

Many patients with severe epistaxis benefit from endoscopic intervention for control of bleeding. Critical maneuvers to improve endoscopic visualization during surgery include head-of-bed elevation, application of topical vasoconstrictors, and local injection of vasonstrictors. Controlled, hypotensive anesthesia may also decrease intraoperative blood loss and improve visualization during surgery. Intractable posterior epistaxis can be controlled with high rates of success with endoscopic sphenopalatine artery ligation. Although less common, intractable anterior epistaxis may be controlled by anterior ethmoid artery ligation once this artery is identified as the primary source. Less common sources of severe epistaxis are also discussed in this article.

Comparative techniques of medial rectus muscle retraction for endoscopic exposure of the medial intraconal space

OBJECTIVE

The medial rectus muscle (MRM) is the medial boundary to the intraconal space of the orbit, and retraction of the MRM is oftentimes necessary for endoscopic removal of intraconal tumors, e.g., orbital hemangioma. We evaluated each of the reported methods of MRM retraction for endoscopic orbital surgery and quantified the degree of intraconal exposure conferred by each method.

METHODS

Eight orbits from four cadaver heads were dissected. In each orbit, medial orbital decompression was performed and the MRM was retracted by using four previously described techniques: (1) external MRM retraction at the globe insertion point by using vessel loop (external group), (2) transseptal MRM retraction by using vessel loop (transseptal group), (3) transchoanal retraction of the MRM by using vessel loop (choanal group), and (4) transseptal four-handed technique by using double ball retraction by a second surgeon (transseptal double ball group). The length, height, and area of exposure of the medial intraconal space were quantified and compared.

RESULTS

The average ± standard deviation (SD) anterior-posterior exposures for the external group, transseptal group, and transseptal double ball group were 17.51 ± 3.39 mm, 16.59 ± 4.16 mm, and 18.0 ± 15.25 mm, respectively. The choanal group provided significantly less exposure (12.39 ± 3.44 mm, p = 0.049) than the other groups. The average ± SD vertical exposures for the transseptal group, choanal group, and transseptal double ball group were 12.53 ± 4.38 mm, 13.05 ± 5.86 mm, and 13.57 ± 3.74 mm, respectively. The external group provided significantly less exposure (4.51 ± 1.56 mm, p = 0.0072) than the other groups. The transseptal and transseptal double ball groups provided the greatest total access by surface area (58.88 ± 26.96 mm(2) and 62.94 ± 34.74 mm(2), respectively) compared with the external and choanal groups (34.82 ± 23.37 mm(2) and 43.10 ± 23.68 mm(2), respectively). Although the transseptal trajectory of MRM retraction was optimal, the difference in total area of exposure between the static vessel loop retraction and the dynamic, four-handed technique with double ball instrument retraction was not significant. Of note, the exposure provided by the choanal technique required the surgeon to work both above and below the muscle.

CONCLUSION

Retraction of the MRM toward the choanae provided the least length of exposure, and external retraction exposed the least height and total area. Transseptal MRM retraction was most favorable and provided the largest endoscopic corridor to the medial intraconal space. A four-handed approach for endoscopic intraconal surgery of the orbit may offer advantages in dynamic adjustments in retraction.

The implications of orbital invasion in sinonasal tract malignancies

In recent decades, the management of sinonasal tumors abutting the orbit has been widely discussed. A real guideline has yet to be proposed, as prospective randomized studies on this topic are very difficult to organize, given the relative rarity of this pathology, the wide spectrum of histologic patterns, and the different clinical behavior of tumors. Nevertheless, in recent years, a better assessment of tumor extension has been obtained thanks to the refinement of preoperative imaging tools and, therefore, more conservative approaches could be adopted, with no worsening of the oncological outcomes and, at the same time, with more attention given to the post-surgical quality of life. Currently, tumors that extend to the bony orbital walls with or without focal infiltration of the periorbit are amenable to orbital preservation. On the other hand, infiltration of extraocular muscles and neurovascular structures are an indication to orbital exenteration. The ideal surgical treatment in cases of limited involvement of orbital fat still remains a matter of debate. We report and discuss the recent English literature on this interesting topic.

Two- versus four-handed techniques for endonasal resection of orbital apex tumors

BACKGROUND

Open versus endonasal resection of orbital apex (OA) tumors is generally based on tumor size, location, and pathology. For endonasal resection, two- and four-handed techniques have been reported, but whether one technique is more optimal based on these tumor features has not been evaluated.

OBJECTIVE

To determine whether two- versus four-handed techniques result in better outcomes after endoscopic resection of OA tumors, and whether either technique is better suited for intra- versus extraconal location and for benign versus malignant pathology.

METHODS

A retrospective review of all expanded endonasal approaches for OA tumors was performed at a single institution from 2009 to 2013. A PubMed database search was also performed to review series published on endonasal OA tumor resection. Across all the cases reviewed, the following data were recorded: two- versus four-handed techniques, intra- versus extraconal tumor location, and benign versus malignant pathology. The relationship between these variables and resection extent was analyzed by the Fisher exact test. Postoperative visual status and complications were also reviewed.

RESULTS

Ten cases from the institution and 94 cases from 17 publications were reviewed. Both two- and four-handed techniques were used to resect extra- and intraconal OA tumors, for both benign and malignant pathology. Four-handed techniques included a purely endonasal approach and a combined endonasal-orbital approach. On univariate analysis, the strongest predictor of complete resection was benign pathology (p = 0.005). No significant difference was found between the extent of resection and a two- versus a four-handed technique. Visual status was improved or unchanged in 94% of cases, and other complications were rare.

CONCLUSION

Benign tumors that involve the medial extraconal and posterior inferomedial intraconal OA can be treated by either two- or four-handed endonasal techniques. Selecting two- versus four-handed techniques and endonasal versus endonasal-orbital four-handed techniques depends mainly on surgeons' experience. Endonasal approaches for malignant OA tumors are less likely to result in complete resection.

Surgical Anatomy of the Medial Wall of the Orbit in 14 Human Cadavers

Objective The aim of our study is to present the anatomical landmarks to perform an endoscopic endonasal approach to the medial wall of the orbit (EEAMO). Material and Methods We performed 14 complete nasal and orbital endoscopic dissections in 7 adult cadaveric heads. Results The EEAMO provides a surgical corridor between the medial rectus muscle superiorly and the inferior rectus muscle inferiorly .The mean distance between the ethmoidal crest and medial rectus muscle was 1.5 cm (range, 1.3-1.9 cm). The width of the medial rectus muscle was 1.2 cm (range, 1-1.5 cm). The main vascular structure in this retrobulbar space was the ophthalmic artery that crosses over the optic nerve in 86% of the cases. In its intraorbital route, the anterior ethmoidal artery and the ethmoidal nerves were situated inferior to the superior oblique muscle in all cases. The posterior ethmoidal artery was found superior to it. We could identify the inferior division of the oculomotor nerve in this surgical approach. Conclusions The EEAMO allows adequate exposure of the space between the medial rectus muscle and the inferior rectus muscle. The location of the ethmoidal crest of the palatine bone, and its relationship with the medial rectus muscle, is a useful anatomical landmark for this surgical approach.

Endoscopic endonasal orbital cavernous hemangioma resection: global experience in techniques and outcomes

BACKGROUND

Endoscopic orbital surgery represents the next frontier in endonasal surgery. The current literature is largely composed of small, heterogeneous, case series with little consensus regarding optimal techniques. The purpose of this study was to combine the experience of multiple international centers to create a composite of the global experience on the endoscopic management of a single type of tumor, the orbital cavernous hemangioma (OCH).

METHODS

This was a retrospective study of techniques for endoscopic OCH resection from 6 centers on 3 continents. Only primary data from strictly endoscopic resection of OCHs were included. Responses were analyzed to qualitatively identify points of both consensus and variability among the different groups.

RESULTS

Data for a total of 23 patients, 10 (43.5%) male and 13 (56.5%) female were collected. The majority of lesions were intraconal (60.9%). The mean ± standard deviation (SD) surgical time was 150.7 ± 75.0 minutes with a mean blood loss of 82.7 ± 49.6 mL. Binarial approaches (26.1%) were used exclusively in the setting of intraconal lesions, which were associated with a higher rate of incomplete resection (31.3%), postoperative diplopia (25.0%), and the need for reconstruction (37.5%) than extraconal lesions. Orthotropia and symmetric orbital appearance were achieved in 60.9% and 78.3% of cases, respectively.

CONCLUSION

Extraconal lesions were managed similarly; however, greater variability was evident for intraconal lesions. These included the laterality and number of hands in the approach, methods of medial rectus retraction, and the need for reconstruction. The increased technical complexity and disparity of techniques in addressing intraconal OCHs suggests that continued research into the optimal management of this subclass of lesions is of significant priority.

Endoscopic surgery of the orbital apex: Outcomes and emerging techniques

OBJECTIVES/HYPOTHESIS

To review our experience with endoscopic orbital apex surgery.

STUDY DESIGN

Retrospective review.

METHODS

All cases with Current Procedural Terminology codes for endoscopic orbital decompression between 2002 and 2011 at two institutions were reviewed. Patients with a diagnosis of Graves orbitopathy or an orbital complication of sinusitis were excluded. Presenting symptoms, lesion location, pathology, surgical outcomes, and complications were examined.

RESULTS

A total of 27 patients were identified. Seventeen (63%) of the patients were men, and the average age was 56 (range = 14-82) years. Eighteen patients had primary orbital apex lesions, and nine patients had sinonasal lesions that predominantly involved the medial orbital apex. The lesions were found to be on the right in 59% of cases. The etiologies include benign (40.7%), malignant (44%), infectious (7.4%), and metastatic (7.4%) lesions. Obtaining a pathologic diagnosis was successful endoscopically in all but two (7.4%) patients, both with lateral lesions. The two-surgeon, four-handed technique and intraoperative image guidance employing fused computed tomography/magnetic resonance imaging were used in the majority of intraconal cases. Complications occurred in three patients (11%) and included myocardial infarction, deep venous thrombosis, and vision loss. There were no cerebrospinal fluid leaks or postoperative hemorrhages. Notably, vision remained stable or improved in all but one patient (3.7% risk of vision decline). Average follow-up was 4 years (range = 1 month-8 years).

CONCLUSIONS

The endoscopic approach to the orbit apex offers significant advantages over traditional external approaches, and should be the preferred approach for all medial and inferior lesions. A two-surgeon multihanded technique can help facilitate difficult cases.

Purely endoscopic trans-nasal management of orbital intraconal cavernous haemangiomas: a systematic review of the literature

The surgical management of medial and inferior orbital lesions is demanding via traditional external approach, since the conic-shaped surgical field is narrow and damage to neural, muscular or vascular structures of the orbit can have serious consequences. In recent years, the evolution of endoscopic endonasal approaches for lesions that goes beyond the nose brought the orbit to the attention of rhinosurgeons. If procedures such as transnasal orbital decompression and lacrimal pathways surgery have been described some decades ago, the last frontier of transnasal orbital surgery, namely intraconal tumor surgery, is a new and rapidly expanding field. Papers describing endoscopic endonasal approaches to the orbit appeared in the international literature, but most of them contain a small number of cases, also because the relatively rarity of intraorbital lesions. We herein report the results of a systematic review of the literature regarding the endoscopic endonasal approach to intraconal cavernous haemangiomas, the most common benign orbital lesion. The endoscopic management of intraconal cavernous haemangiomas results feasible and safe. A critical step of this kind of surgery is the management of the medial rectus muscle, mandatory to expose the intraconal space.

Endoscopic endonasal optic nerve and orbital apex decompression for nontraumatic optic neuropathy: surgical nuances and review of the literature

OBJECT

While several approaches have been described for optic nerve decompression, the endoscopic endonasal route is gaining favor because it provides excellent exposure of the optic canal and the orbital apex in a minimally invasive manner. Very few studies have detailed the experience with nontraumatic optic nerve decompressions, whereas traumatic cases have been widely documented. Herein, the authors describe their preliminary experience with endoscopic endonasal decompression for nontraumatic optic neuropathies (NONs) to determine the procedure's efficacy and delineate its potential indications and limits.

METHODS

The medical reports of patients who had undergone endoscopic endonasal optic nerve and orbital apex decompression for NONs at the Lyon University Neurosurgical Hospital in the period from January 2012 to March 2014 were reviewed. For all cases, clinical and imaging data on the underlying pathology and the patient, including demographics, preoperative and 6-month postoperative ophthalmological assessment results, symptom duration, operative details with video debriefing, as well as the immediate and delayed postoperative course, were collected from the medical records.

RESULTS

Eleven patients underwent endoscopic endonasal decompression for NON in the multidisciplinary skull base surgery unit of the Lyon University Neurosurgical Hospital during the 27-month study period. The mean patient age was 53.4 years, and there was a clear female predominance (8 females and 3 males). Among the underlying pathologies were 4 sphenoorbital meningiomas (36%), 3 optic nerve meningiomas (27%), and 1 each of trigeminal neuroma (9%), orbital apex meningioma (9%), ossifying fibroma (9%), and inflammatory pseudotumor of the orbit (9%). Fifty-four percent of the patients had improved visual acuity at the 6-month follow-up. Only 1 patient whose sphenoorbital meningioma had been treated at the optic nerve atrophy stage continued to worsen despite surgical decompression. The 2 patients presenting with preoperative papilledema totally recovered. One case of postoperative epistaxis was successfully treated using balloon inflation, and 1 case of air swelling of the orbit spontaneously resolved.

CONCLUSIONS

Endoscopic endonasal optic nerve decompression is a safe, effective, and minimally invasive technique affording the restoration of visual function in patients with nontraumatic compressive processes of the orbital apex and optic nerve. The timing of decompression remains crucial, and patients should undergo such a procedure early in the disease course before optic atrophy.