Transcranial Orbital Approaches: comparison of the surgical access and the importance of the zygomatic arch removal

Transcranial Orbital Approaches: comparison of the surgical access and the importance of the zygomatic arch removal | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Transcranial Orbital Approaches: comparison of the surgical access and the importance of the zygomatic arch removal Ahmet Faruk Ozdemir, Omer Furkan Turkis This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8669550/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Orbital surgery may be encountered in neurosurgical practice because of the proximity of lesions to cranial structures and potential transcranial extension. Orbital surgery is divided into microsurgical and endoscopic approaches. Microsurgical techniques can be classified as transorbital or transcranial. To perform these surgical approaches, a thorough understanding of orbital anatomy is essential. Six orbits cadavers with three silicone injected adult heads were used in this study. Following a pterional craniotomy and orbitotomy was performed, central, medial, and lateral transcranial approaches were performed to all specimens. Additionally, a modification to the lateral route was introduced. In this study, we discuss transcranial orbital approaches, identifying suitable approaches for specific lesion locations and highlighting their advantages through cadaveric dissections. Moreover, we demonstrate that the accessible surgical space can be expanded by incorporating a modification to the lateral transcranial approach. In orbital surgery, the appropriate surgical technique should be selected based on the lesion’s location. Mastery of orbital anatomy is a prerequisite for these procedures, and the surgical exposure can be enhanced using the modifications described in our study. Orbit Orbital Surgery Transcranial approaches Zygomatic osteotomy Cadaver dissections Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction The orbit is cone-shaped, located in the anterior part of the skull, and surrounded by bony structures. Anatomical structures essential for visual function are located inside the orbit [ 1 – 3 ]. Cranial nerves within the orbit provide motor innervation to the extraocular muscles, arteries supply blood, and veins provide drainage, all of which are embedded in adipose tissue. These structures were confined within a very tight area with an approximate volume of 30 ml [ 2 – 4 ]. Orbital surgery is categorized into microsurgical and endoscopic approaches. Microsurgical techniques can be classified as either transorbital or transcranial. The lateral, medial, and central routes are the subtypes of transcranial surgery. Endoscopic endonasal and inferolateral endoscopic approaches have been described in the literature as methods of orbital endoscopic surgery [ 1 , 5 – 10 ]. In this study, we describe the anatomy of the orbit, compare transcranial orbital approaches, and introduce a modification of the lateral transcranial approach to access inferior orbital lesions. We aimed to demonstrate the utility of removing the zygomatic arch ot improve surgical exposure. 2. Material and methods Six adult cadaveric orbits were dissected for this study at Istanbul University-Cerrahpasa, Microsurgical Neuroanatomy Laboratory. Three silicone-injected whole heads, without intracranial or orbital pathologies, were used. Whole heads were fixed in 10% formalin solution for three weeks. The stepwise progression of the approaches was documented via photography throughout the dissections. 2.1. Surgical technique A pterional incision was made 1 cm anterior to the tragus, and the skin flap was reflected contralaterally to expose the orbital rim. The temporal muscle was dissected using a subperiosteal technique to expose the craniotomy site. A classic pterional craniotomy was performed on all cadavers and sides. Lateral orbitotomy was combined with the craniotomy exposure to reveal the orbit. Orbital dissections were performed via four different surgical routes: the lateral, medial, central, and expanded lateral transcranial orbital approaches. 2.2. Ehtical Compliance: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Prof. Dr. Suleyman Yalcin City Hospital (Date: December 4, 2025, No:2025/0296). 3. Results 3.1. Dissection of the orbit The orbit can be accessed using several transcranial approaches. The viability of these options was evaluated according to the site and size of the lesions. For small lesions, the orbit can be reached by removing the orbital roof following a pterional craniotomy. The cranio-orbitozygomatic(COZ)approach cloud be preferred for larger lesions. A pterional incision was made 1 cm anterior to the tragus, and the skin flap was reflected to the opposite side to expose the craniotomy site and orbital rim [ 1 , 11 , 12 ]. The temporal muscle dissection was performed in a subperiosteal fashion, and the craniotomy site was exposed. Depending on the size and location of the lesion, if a frontal craniotomy is preferred, the orbit is accessed by performing orbitotomy after removing the bone flap. In contrast, COZ craniotomy provides direct access to the periorbital area by removing the orbital roof and lateral wall. Upon reaching the orbit, three alternative surgical corridors are available to proceed into the intraconal space: the lateral approach (lateral to the levator and superior rectus muscles), the medial approach (medial to these muscles), and the central approach (between these two muscles) [ 5 , 6 , 9 , 10 ]. These surgical routes can be utilized in combination with the frontal, frontotemporal, and COZ approaches [ 1 ]. 3.1.1. Lateral transcranial approach to orbit After the craniotomy and orbitotomy were completed via the pterional approach, the frontal nerve, emerging from the ophthalmic branch of the trigeminal nerve(CN V), was visualized superior to the orbit, with the lacrimal nerve located laterally. The trochlear nerve(CN IV), innervating the superior oblique muscle (SOM), was observed medially. The frontal nerve divides into the supraorbital and supratrochlear branches. Following the removal of adipose tissue, the levator, superior oblique, and lateral rectus muscles were revealed. The frontal nerve was identified over the levator muscle, the lacrimal nerve lateral to the lateral rectus, and the trochlear nerve over the SOM. In the dissection, the levator muscle was reflected superiorly together with the superior ophthalmic vein (SOV), while the lateral rectus muscle was reflected inferiorly [ 5 , 6 ]. This corridor provides access to the compartment superolateral to the optic nerve, ophthalmic artery, and the superior division of the oculamotor nerve(CN III). However, structures located deeper within the optic nerve region could not be identified ( Fig. 1 ) . In this study, a zygomatic osteotomy was added to the lateral transcranial approach, enlarging the surgical corridor to reveal anatomical structures inferior and inferolateral to the optic nerve. The structures exposed via this zygomatic extension include the inferior rectus muscle, medial and lateral branches of CN III, ciliary ganglion, the inferolateral aspect of the optic nerve, and the central retinal artery. 3.1.2. Medial transcranial approach to orbit The medial transcranial approach is performed by advancing between the frontal nerve, levator, and superior rectus muscles laterally, and the trochlear nerve, superior oblique, and medial rectus muscles medially. Among these structures, the nasociliary nerve, ophthalmic artery, and their branches are commonly encountered. By retracting the levator and superior rectus muscles laterally, the superior oblique muscle, medial rectus muscle, and nasociliary arteries can be observed medially. The inferior rectus muscle can be reached inferiorly. Retracting the levator and superior rectus muscles allows visualization of the nasociliary nerve and ophthalmic artery laterally, and the superior oblique and medial rectus muscles medially, providing a larger surgical corridor deep into the medial side of the optic nerve. When the SOM is retracted medially, the posterior ethmoidal artery and nerve are exposed along the continuation of the nasociliary nerve and ophthalmic artery ( Fig. 2 ) [ 5 , 9 ]. 3.1.3. Central transcranial approach to orbit The frontal nerve running over the levator muscle was released. After reflecting it laterally, the levator and superior rectus muscles were reflected anteriorly to expose deeper structures. This maneuver exposed the superior division of CN III. Neighboring structures include the trochlear nerve, nasociliary nerve, frontal nerve, and ophthalmic artery. By retracting the superior division of CN III medially, the optic nerve and the ophthalmic artery’s entry into the orbit can be visualized. The optic nerve was retracted medially, and the superior part of CN III was retracted laterally to reveal the branch of the inferior division of CN III leading to the inferior oblique muscle, as well as branches leading to the inferior and medial rectus muscles ( Fig. 3 ) [ 5 ]. 4. Discussion Tumors and vascular lesions are frequently encountered indications for orbital surgery. The most common intraorbital lesions are cavernomas. Additionally, optic nerve gliomas, meningiomas, osteomas, fibrous dysplasia, varices, and metastases can be observed [ 13 – 15 ]. Surgical approaches to the orbit can be classified into microsurgical or endoscopic techniques [ 16 ]. Microsurgical routes are selected according to the location of the targeted pathology [ 2 , 4 ]. The location of a lesion is described based on its relationship to the optic nerve. Transorbital approaches are suitable for lesions located in the anterior one-third of the orbit [ 16 ], while transcranial techniques are generally preferred for lesions in the posterior one-third [ 6 ]. Inferomedial lesions can be treated using an endoscopic endonasal approach, and inferolateral lesions using an inferolateral endoscopic approach [ 7 , 17 ]. Lesion location is not the sole criterion; the size and nature of the tumor, as well as the surgical goal (biopsy, debulking, gross total excision, or total excision), are factors that must be evaluated before determining the surgical route [ 16 ]. The transcranial approach is applicable for all tumors with intracranial extension located at the orbital apex and optic canal [ 4 , 5 ]. Orbitofrontal or COZ craniotomy is generally used in these approaches [ 8 ]. Pterional craniotomy combined with orbital roof removal is suitable for small lesions, whereas the COZ approach provides a wider surgical corridor for larger lesions. Regardless of the chosen craniotomy, three different routes into the intraconal space have been described: the lateral, medial, and central approaches. The medial approach is generally preferred for lesions located medial to the optic nerve [ 8 , 9 ]. After retracting the SOM laterally and the superior rectus and levator muscles medially, the optic nerve and medial structures can be accessed. In this approach, following an incision between the tendons of the annulus of Zinn (superior and medial rectus muscles), the optic nerve can be easily accessed, facilitating lesion removal while preserving anatomical structures. Using the transcranial central approach, the middle one-third of the intraorbital optic nerve can be reached by advancing through the levator and superior rectus muscles [ 3 ]. This approach can be performed in two ways, depending on the localization of the frontal nerve. In the first method, the frontal nerve is retracted medially along with the levator muscle; while the risk of frontal nerve damage is low, accessing deep orbital structures is difficult. Alternatively, the frontal nerve is retracted laterally with the superior rectus muscle, allowing access to deep orbital structures but increasing the risk of nerve injury. The lateral orbital approach is used for tumors and lesions in the superior temporal compartments of the orbit [ 10 ]. In this approach, the optic nerve is reached by retracting the lateral rectus muscle laterally and the superior rectus and levator muscles medially. In the lateral transcranial approach, lesions superolateral to the optic nerve can be reached by inferomedial advancement through the superior and lateral rectus muscles. This approach varies depending on the handling of the SOV [ 10 ]. If the SOV is retracted medially with the levator and superior rectus muscles without connective tissue dissection, the lateral side of the optic nerve is accessible without damaging soft tissue, including the nasociliary nerve; however, the SOV may obscure the surgical field, complicating access to the deep apical region [ 3 ]. Alternatively, retracting the SOV and lateral rectus muscles laterally allows access to the area superolateral to the optic nerve, though SOV retraction carries a risk of thrombosis and injury [ 10 ]. The choice of surgical approach for orbital tumors depends more on the location relative to the optic nerve than on the pathology itself [ 18 ]. A fundamental principle in determining the surgical route is to avoid crossing over the optic nerve to work on the contralateral side. Transcranial approaches may be challenging regarding accessibility to inferomedial and inferolateral lesions, leading to the increased popularity of endoscopic approaches for lesions inferior to the optic nerve. In our study, a zygomatic osteotomy was added to the lateral transcranial approach, enlarging the surgical corridor by excluding the superior rectus superiorly and the lateral rectus inferiorly. This modification revealed anatomical structures inferior and inferolateral to the optic nerve. Access to deeper structures located inferior and inferolateral to the orbit—such as the inferior rectus muscle, the medial and lateral branches of CN III, the ciliary ganglion, the inferolateral aspect of the optic nerve, and the central retinal artery—was demonstrated using this modified lateral transcranial approach ( Fig. 4 ) . 5. Conclusion Orbital anatomy includes complex vascular and neural structures. A thorough knowledge of this anatomy is required to perform surgery in this region safely. The surgical approach should be determined primarily by lesion localization. The modified lateral transcranial method described here provides a wider surgical corridor through different retraction techniques and is a preferable option for inferior and inferolateral lesions. Abbreviations COZ Cranio- orbitozygomatic SOM Superior Oblique Muscle IOM Inferior Oblique Muscle SOV Superior Ophthalmic Vein CN Cranial Nerve Declarations 6. Funding: This study did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. 7. Conflict of interest : The authors declare that they have no conflict of interest. 8. Author contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Ahmet Faruk Ozdemir and Omer Furkan Turkis. The first draft of the manuscript was written by Ahmet Faruk Ozdemir and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. References Rhoton AL, Jr (2002) The orbit. Neurosurgery 51(4 Suppl):S303–S334 Gospe SM 3rd, Bhatti MT (2018) Orbital Anatomy. Int Ophthalmol Clin 58(2):5–23. https://doi.org/10.1097/IIO.0000000000000214 Hayek G, Mercier P, Fournier HD (2006) Anatomy of the orbit and its surgical approach. Adv Tech Stand Neurosurg 31:35–71. https://doi.org/10.1007/3-211-32234-5_2 + 9 Natori Y, Rhoton AL, Jr (1994) Transcranial approach to the orbit: microsurgical anatomy. J Neurosurg 81(1):78–86. https://doi.org/10.3171/jns.1994.81.1.0078 Arai H, Sato K, Katsuta T, Rhoton AL Jr (1996) Lateral approach to intraorbital lesions: anatomic and surgical considerations. 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Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 04 May, 2026 Reviews received at journal 12 Apr, 2026 Reviews received at journal 01 Apr, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviewers agreed at journal 31 Mar, 2026 Reviewers invited by journal 31 Mar, 2026 Editor assigned by journal 18 Feb, 2026 Submission checks completed at journal 23 Jan, 2026 First submitted to journal 22 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8669550","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":615773669,"identity":"9ece8503-2c01-4e7b-9dfe-82ce918857ba","order_by":0,"name":"Ahmet Faruk Ozdemir","email":"data:image/png;base64,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","orcid":"","institution":"Istanbul Medeniyet University","correspondingAuthor":true,"prefix":"","firstName":"Ahmet","middleName":"Faruk","lastName":"Ozdemir","suffix":""},{"id":615773670,"identity":"a14dcaa0-3f76-4aa4-8474-0b3592c23f8a","order_by":1,"name":"Omer Furkan Turkis","email":"","orcid":"","institution":"Kepez State Hospital","correspondingAuthor":false,"prefix":"","firstName":"Omer","middleName":"Furkan","lastName":"Turkis","suffix":""}],"badges":[],"createdAt":"2026-01-22 12:10:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8669550/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8669550/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106402966,"identity":"94895dce-d638-4510-8fc9-4b0bcf2cc1e7","added_by":"auto","created_at":"2026-04-08 09:13:15","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":7739653,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eLateral transcranial approach to orbit:\u003c/em\u003e \u003cstrong\u003eA: \u003c/strong\u003eThe thin bony roof of the orbit is removed and entry of the optic and oculomotor nerves into the orbit are shown. \u003cstrong\u003eB: \u003c/strong\u003eThe appearance of the orbit without dissection and retraction after the bone roof and superficial adipose tissue removal. \u003cstrong\u003eC:\u003c/strong\u003eAnatomical structures that can be reached by proceeding between the superior rectus and lateral rectus muscles after lateral rectus retraction in the classical lateral approach of the orbit. \u003cstrong\u003eD:\u003c/strong\u003e In classical lateral orbital approach, revealed anatomic structures after the Zinn ring is released.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e\u003c/em\u003e \u003cem\u003eCN; Cranial Nerve, N; Nerve, Sup; Superior, Obl; Oblique, M; Muscle, Med; Medial, Lat; Lateral, Front; Frontal, Inf; Inferior, Lac; Lacrimal, Ophth; Ophthalmic, Rec; Rectus, A; Artery, Div; Division.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8669550/v1/94127fe40b333f8b5231d4ac.jpg"},{"id":106189812,"identity":"8f2694e9-b59b-4d7e-92d1-4e32b55747fc","added_by":"auto","created_at":"2026-04-05 17:11:18","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":7969530,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eMedial transcranial approach to orbit \u003c/em\u003e\u003cstrong\u003eA: \u003c/strong\u003eThe medial transcranial approach is carried out by advancing between the frontal nerve, levator and superior rectus muscles in the middle, and the trochlear nerve, superior oblique, and medial rectus muscles. Among these structures, the nasociliary nerve, ophthalmic artery, and its branches are encountered. \u003cstrong\u003eB:\u003c/strong\u003eAfter retraction of the levator and superior rectus muscles laterally, the superior oblique, medial rectus muscles, nasociliary arteries have been left medially and the inferior rectus muscle is reached deeply. \u003cstrong\u003eC:\u003c/strong\u003e After removal of levator and superior rectus muscles, retraction of nasociliary nerve and ophthalmic artery and its branches to the lateral, the superior oblique and medial rectus muscles to the medial, a larger surgical corridor could be supplied deep in the medial side of the optic nerve. \u003cstrong\u003eD:\u003c/strong\u003e After the superior oblique muscle has been retracted medially, posterior ethmoidal artery and nerve are exposed in the continuation of the ophthalmic artery and nasociliary nerve.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e\u003c/em\u003e \u003cem\u003eSup; Superior, Obl; Oblique, Rec; Rectus, M; Muscle, A; Artery, Lac; Lacrimal, Front; Frontal, Lat; Lateral, Med; Medial, N; Nerve, Inf; Inferior, CN; Cranial Nerve, Post; Posterior.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8669550/v1/fd8fad9ad99341ac64d9721f.jpg"},{"id":106402771,"identity":"48260ff7-bb95-4c8e-a521-41ae3d2d5353","added_by":"auto","created_at":"2026-04-08 09:12:48","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":7189914,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eCentral transcranial approach to orbit \u003c/em\u003e\u003cstrong\u003eA: \u003c/strong\u003eThe frontal nerve running over the levator muscle has been released and after it has been moved laterally, levator and superior rectus muscles have been reflected anteriorly to expose deeper structure. \u003cstrong\u003eB:\u003c/strong\u003e After reflecting superior rectus and levator muscle anteriorly, superior division of CN III has been exposed. The neighboring structures are trochlear nerve, nasociliary nerve, frontal nerve, ophthalmic artery. \u003cstrong\u003eC: \u003c/strong\u003eBy retracting the superior division of CN III medially, the optic nerve and ophthalmic artery’s entrance into the orbit is seen. \u003cstrong\u003eD:\u003c/strong\u003e Optic nerve and superior part of CN III are retracted to the medial and lateral respectively to reveal the branch of the inferior part of CN III leading to the inferior oblique muscle and the branches leading to the inferior and medial rectus muscles.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e\u003c/em\u003e \u003cem\u003eSup; Superior, Obl; Oblique, Rec; Rectus, M; Muscle, A; Artery, Lac; Lacrimal, Front; Frontal, Lat; Lateral, Med; Medial, N; Nerve, Inf; Inferior, CN; Cranial Nerve, Div; Division.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8669550/v1/a9aa557366c82158efc03f63.jpg"},{"id":106189815,"identity":"b5965234-5ee1-475c-a52d-2d7ec52ab6eb","added_by":"auto","created_at":"2026-04-05 17:11:18","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":7855404,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eExtended lateral transcranial approach to orbit by removing the zygomatizc arch. \u003c/em\u003e\u003cstrong\u003eA: \u003c/strong\u003eAfter craniotomy and orbitotomy was completed with the COZ approach, the frontal nerve emerging from the ophthalmic branch of the trigeminal nerve was seen superior to the orbit, and lacrimal nerve lateral to the orbit. The trochlear nerve innervating the superior oblique muscle was observed medially. The frontal nerve divides into supraorbital and supratrochlear branches. \u003cstrong\u003eB:\u003c/strong\u003e Levator, superior oblique and lateral rectus muscles are revealed after removing adipose tissue and frontal nerve is seen over the levator muscle, lacrimal nerve is located laterally to lateral rectus and trochlear nerve lies over the SOM (Superior Oblique Muscle). \u003cstrong\u003eC:\u003c/strong\u003e In the dissection we have performed, the levator muscle was reflected together with SOV superiorly, and the lateral rectus muscle inferiorly. Following the surgical corridor in between, optic nerve, ophthalmic artery, inferior division of CN III and its medial and lateral branches, ciliary ganglion can be exposed respectively. \u003cstrong\u003eD:\u003c/strong\u003e The superior and inferior parts of CN III can be seen with the lateral orbital approach. The nasociliary nerve and its afferent branch to the ciliary ganglion are exposed. The medial and lateral branches of the inferior part of CN III and the ciliary ganglion are revealed.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e\u003c/em\u003e \u003cem\u003eCN; Cranial Nerve, N; Nerve, Sup; Superior, Obl; Oblique, M; Muscle, Gang; Ganglion, A; Artery, Inf; Inferior, Rec; Rectus, SOV; Superior Ophtalmic Vein, Div; Division.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8669550/v1/cb05e30d4ca669827bdd2bec.jpg"},{"id":106405547,"identity":"4264e5e2-fc9a-4932-a9b5-a1efa8090d1d","added_by":"auto","created_at":"2026-04-08 09:27:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":31255391,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8669550/v1/58ee4613-117d-4d6e-96eb-eb60b804326a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Transcranial Orbital Approaches: comparison of the surgical access and the importance of the zygomatic arch removal","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe orbit is cone-shaped, located in the anterior part of the skull, and surrounded by bony structures. Anatomical structures essential for visual function are located inside the orbit [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Cranial nerves within the orbit provide motor innervation to the extraocular muscles, arteries supply blood, and veins provide drainage, all of which are embedded in adipose tissue. These structures were confined within a very tight area with an approximate volume of 30 ml [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOrbital surgery is categorized into microsurgical and endoscopic approaches. Microsurgical techniques can be classified as either transorbital or transcranial. The lateral, medial, and central routes are the subtypes of transcranial surgery. Endoscopic endonasal and inferolateral endoscopic approaches have been described in the literature as methods of orbital endoscopic surgery [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan additionalcitationids=\"CR6 CR7 CR8 CR9\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study, we describe the anatomy of the orbit, compare transcranial orbital approaches, and introduce a modification of the lateral transcranial approach to access inferior orbital lesions. We aimed to demonstrate the utility of removing the zygomatic arch ot improve surgical exposure.\u003c/p\u003e"},{"header":"2. Material and methods","content":"\u003cp\u003eSix adult cadaveric orbits were dissected for this study at Istanbul University-Cerrahpasa, Microsurgical Neuroanatomy Laboratory. Three silicone-injected whole heads, without intracranial or orbital pathologies, were used. Whole heads were fixed in 10% formalin solution for three weeks. The stepwise progression of the approaches was documented via photography throughout the dissections.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Surgical technique\u003c/h2\u003e \u003cp\u003eA pterional incision was made 1 cm anterior to the tragus, and the skin flap was reflected contralaterally to expose the orbital rim. The temporal muscle was dissected using a subperiosteal technique to expose the craniotomy site. A classic pterional craniotomy was performed on all cadavers and sides. Lateral orbitotomy was combined with the craniotomy exposure to reveal the orbit. Orbital dissections were performed via four different surgical routes: the lateral, medial, central, and expanded lateral transcranial orbital approaches.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. Ehtical Compliance:\u003c/h2\u003e \u003cp\u003eThis study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Prof. Dr. Suleyman Yalcin City Hospital (Date: December 4, 2025, No:2025/0296).\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Dissection of the orbit\u003c/h2\u003e \u003cp\u003eThe orbit can be accessed using several transcranial approaches. The viability of these options was evaluated according to the site and size of the lesions. For small lesions, the orbit can be reached by removing the orbital roof following a pterional craniotomy. The cranio-orbitozygomatic(COZ)approach cloud be preferred for larger lesions. A pterional incision was made 1 cm anterior to the tragus, and the skin flap was reflected to the opposite side to expose the craniotomy site and orbital rim [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The temporal muscle dissection was performed in a subperiosteal fashion, and the craniotomy site was exposed. Depending on the size and location of the lesion, if a frontal craniotomy is preferred, the orbit is accessed by performing orbitotomy after removing the bone flap. In contrast, COZ craniotomy provides direct access to the periorbital area by removing the orbital roof and lateral wall. Upon reaching the orbit, three alternative surgical corridors are available to proceed into the intraconal space: the lateral approach (lateral to the levator and superior rectus muscles), the medial approach (medial to these muscles), and the central approach (between these two muscles) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. These surgical routes can be utilized in combination with the frontal, frontotemporal, and COZ approaches [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1. Lateral transcranial approach to orbit\u003c/h2\u003e \u003cp\u003eAfter the craniotomy and orbitotomy were completed via the pterional approach, the frontal nerve, emerging from the ophthalmic branch of the trigeminal nerve(CN V), was visualized superior to the orbit, with the lacrimal nerve located laterally. The trochlear nerve(CN IV), innervating the superior oblique muscle (SOM), was observed medially. The frontal nerve divides into the supraorbital and supratrochlear branches. Following the removal of adipose tissue, the levator, superior oblique, and lateral rectus muscles were revealed. The frontal nerve was identified over the levator muscle, the lacrimal nerve lateral to the lateral rectus, and the trochlear nerve over the SOM. In the dissection, the levator muscle was reflected superiorly together with the superior ophthalmic vein (SOV), while the lateral rectus muscle was reflected inferiorly [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. This corridor provides access to the compartment superolateral to the optic nerve, ophthalmic artery, and the superior division of the oculamotor nerve(CN III). However, structures located deeper within the optic nerve region could not be identified \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn this study, a zygomatic osteotomy was added to the lateral transcranial approach, enlarging the surgical corridor to reveal anatomical structures inferior and inferolateral to the optic nerve. The structures exposed via this zygomatic extension include the inferior rectus muscle, medial and lateral branches of CN III, ciliary ganglion, the inferolateral aspect of the optic nerve, and the central retinal artery.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e3.1.2. Medial transcranial approach to orbit\u003c/h2\u003e \u003cp\u003eThe medial transcranial approach is performed by advancing between the frontal nerve, levator, and superior rectus muscles laterally, and the trochlear nerve, superior oblique, and medial rectus muscles medially.\u003c/p\u003e \u003cp\u003eAmong these structures, the nasociliary nerve, ophthalmic artery, and their branches are commonly encountered. By retracting the levator and superior rectus muscles laterally, the superior oblique muscle, medial rectus muscle, and nasociliary arteries can be observed medially. The inferior rectus muscle can be reached inferiorly. Retracting the levator and superior rectus muscles allows visualization of the nasociliary nerve and ophthalmic artery laterally, and the superior oblique and medial rectus muscles medially, providing a larger surgical corridor deep into the medial side of the optic nerve. When the SOM is retracted medially, the posterior ethmoidal artery and nerve are exposed along the continuation of the nasociliary nerve and ophthalmic artery \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e3.1.3. Central transcranial approach to orbit\u003c/h2\u003e \u003cp\u003eThe frontal nerve running over the levator muscle was released. After reflecting it laterally, the levator and superior rectus muscles were reflected anteriorly to expose deeper structures. This maneuver exposed the superior division of CN III. Neighboring structures include the trochlear nerve, nasociliary nerve, frontal nerve, and ophthalmic artery. By retracting the superior division of CN III medially, the optic nerve and the ophthalmic artery\u0026rsquo;s entry into the orbit can be visualized. The optic nerve was retracted medially, and the superior part of CN III was retracted laterally to reveal the branch of the inferior division of CN III leading to the inferior oblique muscle, as well as branches leading to the inferior and medial rectus muscles \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4. Discussion","content":"\u003cp\u003eTumors and vascular lesions are frequently encountered indications for orbital surgery. The most common intraorbital lesions are cavernomas. Additionally, optic nerve gliomas, meningiomas, osteomas, fibrous dysplasia, varices, and metastases can be observed [\u003cspan additionalcitationids=\"CR14\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Surgical approaches to the orbit can be classified into microsurgical or endoscopic techniques [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Microsurgical routes are selected according to the location of the targeted pathology [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The location of a lesion is described based on its relationship to the optic nerve. Transorbital approaches are suitable for lesions located in the anterior one-third of the orbit [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e], while transcranial techniques are generally preferred for lesions in the posterior one-third [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Inferomedial lesions can be treated using an endoscopic endonasal approach, and inferolateral lesions using an inferolateral endoscopic approach [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLesion location is not the sole criterion; the size and nature of the tumor, as well as the surgical goal (biopsy, debulking, gross total excision, or total excision), are factors that must be evaluated before determining the surgical route [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The transcranial approach is applicable for all tumors with intracranial extension located at the orbital apex and optic canal [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Orbitofrontal or COZ craniotomy is generally used in these approaches [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Pterional craniotomy combined with orbital roof removal is suitable for small lesions, whereas the COZ approach provides a wider surgical corridor for larger lesions. Regardless of the chosen craniotomy, three different routes into the intraconal space have been described: the lateral, medial, and central approaches.\u003c/p\u003e \u003cp\u003eThe medial approach is generally preferred for lesions located medial to the optic nerve [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. After retracting the SOM laterally and the superior rectus and levator muscles medially, the optic nerve and medial structures can be accessed. In this approach, following an incision between the tendons of the annulus of Zinn (superior and medial rectus muscles), the optic nerve can be easily accessed, facilitating lesion removal while preserving anatomical structures.\u003c/p\u003e \u003cp\u003eUsing the transcranial central approach, the middle one-third of the intraorbital optic nerve can be reached by advancing through the levator and superior rectus muscles [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. This approach can be performed in two ways, depending on the localization of the frontal nerve. In the first method, the frontal nerve is retracted medially along with the levator muscle; while the risk of frontal nerve damage is low, accessing deep orbital structures is difficult. Alternatively, the frontal nerve is retracted laterally with the superior rectus muscle, allowing access to deep orbital structures but increasing the risk of nerve injury.\u003c/p\u003e \u003cp\u003eThe lateral orbital approach is used for tumors and lesions in the superior temporal compartments of the orbit [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In this approach, the optic nerve is reached by retracting the lateral rectus muscle laterally and the superior rectus and levator muscles medially. In the lateral transcranial approach, lesions superolateral to the optic nerve can be reached by inferomedial advancement through the superior and lateral rectus muscles. This approach varies depending on the handling of the SOV [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. If the SOV is retracted medially with the levator and superior rectus muscles without connective tissue dissection, the lateral side of the optic nerve is accessible without damaging soft tissue, including the nasociliary nerve; however, the SOV may obscure the surgical field, complicating access to the deep apical region [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Alternatively, retracting the SOV and lateral rectus muscles laterally allows access to the area superolateral to the optic nerve, though SOV retraction carries a risk of thrombosis and injury [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe choice of surgical approach for orbital tumors depends more on the location relative to the optic nerve than on the pathology itself [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. A fundamental principle in determining the surgical route is to avoid crossing over the optic nerve to work on the contralateral side. Transcranial approaches may be challenging regarding accessibility to inferomedial and inferolateral lesions, leading to the increased popularity of endoscopic approaches for lesions inferior to the optic nerve.\u003c/p\u003e \u003cp\u003eIn our study, a zygomatic osteotomy was added to the lateral transcranial approach, enlarging the surgical corridor by excluding the superior rectus superiorly and the lateral rectus inferiorly. This modification revealed anatomical structures inferior and inferolateral to the optic nerve. Access to deeper structures located inferior and inferolateral to the orbit\u0026mdash;such as the inferior rectus muscle, the medial and lateral branches of CN III, the ciliary ganglion, the inferolateral aspect of the optic nerve, and the central retinal artery\u0026mdash;was demonstrated using this modified lateral transcranial approach \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"5. Conclusion","content":"\u003cp\u003eOrbital anatomy includes complex vascular and neural structures. A thorough knowledge of this anatomy is required to perform surgery in this region safely. The surgical approach should be determined primarily by lesion localization. The modified lateral transcranial method described here provides a wider surgical corridor through different retraction techniques and is a preferable option for inferior and inferolateral lesions.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCOZ\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCranio- orbitozygomatic\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSOM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSuperior Oblique Muscle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIOM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eInferior Oblique Muscle\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSOV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSuperior Ophthalmic Vein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCN\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCranial Nerve\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003e6. Funding:\u003c/h2\u003e\n\u003cp\u003eThis study did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e7. Conflict of interest\u003c/strong\u003e:\u003c/h2\u003e\n\u003cp\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e8. Author contributions\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Ahmet Faruk Ozdemir and Omer Furkan Turkis. The first draft of the manuscript was written by Ahmet Faruk Ozdemir and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eRhoton AL, Jr (2002) The orbit. 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Operative Neurosurg (Hagerstown Md) 12(4):360\u0026ndash;373. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1227/NEU.0000000000001145\u003c/span\u003e\u003cspan address=\"10.1227/NEU.0000000000001145\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Orbit, Orbital Surgery, Transcranial approaches, Zygomatic osteotomy, Cadaver dissections","lastPublishedDoi":"10.21203/rs.3.rs-8669550/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8669550/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOrbital surgery may be encountered in neurosurgical practice because of the proximity of lesions to cranial structures and potential transcranial extension. Orbital surgery is divided into microsurgical and endoscopic approaches. Microsurgical techniques can be classified as transorbital or transcranial. To perform these surgical approaches, a thorough understanding of orbital anatomy is essential. Six orbits cadavers with three silicone injected adult heads were used in this study. Following a pterional craniotomy and orbitotomy was performed, central, medial, and lateral transcranial approaches were performed to all specimens. Additionally, a modification to the lateral route was introduced. In this study, we discuss transcranial orbital approaches, identifying suitable approaches for specific lesion locations and highlighting their advantages through cadaveric dissections. Moreover, we demonstrate that the accessible surgical space can be expanded by incorporating a modification to the lateral transcranial approach. In orbital surgery, the appropriate surgical technique should be selected based on the lesion\u0026rsquo;s location. Mastery of orbital anatomy is a prerequisite for these procedures, and the surgical exposure can be enhanced using the modifications described in our study.\u003c/p\u003e","manuscriptTitle":"Transcranial Orbital Approaches: comparison of the surgical access and the importance of the zygomatic arch removal","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-05 17:11:13","doi":"10.21203/rs.3.rs-8669550/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-04T07:08:49+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-12T12:58:50+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-01T08:18:19+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"113804958904510082954849894507562662297","date":"2026-03-31T12:47:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"318007435630904442548608233108383930171","date":"2026-03-31T12:42:20+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-31T10:41:25+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-18T17:34:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-23T08:36:25+00:00","index":"","fulltext":""},{"type":"submitted","content":"Neurosurgical Review","date":"2026-01-22T11:28:56+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"neurosurgical-review","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nrev","sideBox":"Learn more about [Neurosurgical Review](https://www.springer.com/journal/10143)","snPcode":"10143","submissionUrl":"https://submission.nature.com/new-submission/10143/3","title":"Neurosurgical Review","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"f91d11c7-632f-4438-8bcf-54e8baade796","owner":[],"postedDate":"April 5th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-04T07:08:49+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-18T21:08:15+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-05 17:11:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8669550","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8669550","identity":"rs-8669550","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}