Transorbital Approach Research Articles

Assessing the Feasibility of Selective Piezoelectric Osteotomy in Transorbital Approach to the Middle Cranial Fossa: Anatomical and Quantitative Study and Surgical Implications

ObjectivesTo verify the feasibility and to discuss advantages and disadvantages of a piezoelectric orbitotomy (PO) during Superior Eyelid Endoscopic Transorbital Approach (SETOA). MethodsFive adult specimens underwent exoscopic/endoscopic SETOA to middle cranial fossa. The surgical corridor was created via piezoelectric orbitotomy by performing three selective and safe micrometric bone cuts providing a one-piece trapezoid bone flap which was repositioned and secured at the end of procedure. A 3D scan of the bone flap allowed us to reconstruct a 3D model and calculate its volume. An illustrative case demonstrating the application of this novel technique was also presented. ResultsAnatomical-morphometric quantitative analysis showed a mean bony-volume gain of 1,574.26 mm3 by using PO.PO yielded concrete surgical advantages and theoretical benefits in terms of functional and esthetic outcomes. All osteotomies were micrometric clear-cut and precise, resulting in a very thin bony gap; a complete sparing of soft tissues and neurovascular structures in- and around the orbit was observed. Lateral orbital wall reconstruction by replacing the bone flap aims to mitigate the risk of enophthalmos, proptosis, CSF leakage, pseudomeningocele and pulsatile headache, which represent significant challenges in the relevant literature. ConclusionPO may offer a viable, selective, effective, safe alternative to high-speed drilling during SETOA, especially for patients affected by intra-axial pathologies in which a watertight closure is mandatory. This procedure could prevent/decrease the risk of some of the main postoperative complications associated to the standard SETOA, resulting potentially in better functional and esthetic outcome.

Endoscopic transorbital approach for resection of mediobasal temporal lesions using an optic radiation-sparing strategy.

The endoscopic transorbital approach (ETOA) has emerged as a promising minimally invasive technique for resection of lesions in the mediobasal temporal region (MTR) due to its potential to preserve the integrity of the optic radiation (OR). This study evaluated the safety and efficacy of ETOA using an OR-sparing surgical strategy for mediobasal temporal lesions. A retrospective review was conducted of the medical records of 15 patients (7 females and 8 males) who underwent ETOA for lesions in the MTR between November 2017 and November 2022. Preoperative diffusion tensor imaging (DTI) tractography of the OR was utilized in all cases for surgical planning to visualize the spatial relations between the OR and the target mediobasal temporal lesion. The median age of the treated patients was 43 years (range 22-76 years), with a median follow-up duration of 12 months (range 6-35 months). Eleven lesions (73.3%) involved only the anterior segment of the MTR, while 4 lesions (26.7%) affected both the anterior and middle segments. Gross-total resection was achieved in 13 patients (86.7%) and subtotal resection in 2 (13.3%). The final pathologies included low-grade glioma (n = 5), cavernous malformation (n = 3), glioblastoma multiforme (n = 2), multinodular and vacuolating neuronal tumor (n = 1), pleomorphic xanthoastrocytoma (n = 1), anaplastic oligodendroglioma (n = 1), adenoid cystic carcinoma (n = 1), and metastatic renal cell carcinoma (n = 1). Postoperative neuro-ophthalmological examinations revealed that all patients maintained their previous visual function. Follow-up DTI tractography further confirmed the preservation of the preoperative ORs in the treated patients. No postoperative CSF leaks, infections, or cosmetic problems occurred in this series. The combined use of ETOA and OR tractography appears to be a feasible approach for resecting lesions involving the MTR, especially in the anterior segment. In the authors' experience, this surgical strategy enables maximal safe resection while minimizing the risk of postoperative visual dysfunction. Further studies with larger sample sizes are warranted to validate these findings and assess long-term outcomes.

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

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

Biphenotypic Sinonasal Sarcoma with Orbital Invasion: A Literature Review and Modular System of Surgical Approaches.

Background: Biphenotypic sinonasal sarcoma is a rare low-grade tumor arising from the sinonasal tract, featuring locally aggressive biological behavior, with a tendency to invade the orbit and skull base. There are no defined guidelines of treatment; thus, the management varies among different institutions. The aim of the present study is to provide a modular system of surgical approaches according to the lesion pattern of growth from a literature review. Materials and Methods: A comprehensive and detailed literature review on the PubMed and Embase online electronic databases on biphenotypic sinonasal sarcoma with orbital invasion was conducted. A personal case exhibiting peculiar features was also added. Demographic (patient's sex and age), clinical (presenting symptoms and time to treatment), neuroradiological (anatomical origin and pattern of growth), and treatment (type of treatment, surgical approach, extent of resection, peri- and postoperative complications, and adjuvant therapies) data, as well as clinical outcome, recurrence rates, and overall survival, were analyzed. Results: Thirty-one patients harboring biphenotypic sinonasal sarcoma with orbital invasion were identified. Tumors mainly affected female patients (66.7%) and a middle-aged population (median 55.2 years old). Simultaneous skull base involvement occurred in most cases (80.6%). Surgery was performed in all but one case (97%), as unique treatment (59%) or in association with radio-(23.5%) and/or chemotherapy (5.9%/2.9%), allowing for gross total tumor resection in most cases (66.7%). The endoscopic endonasal approach was the most adopted surgical corridor (51.7%). The local recurrence rate was 19.3%, and only two cases of tumor-related mortality occurred. Conclusions: Surgery is the only curative treatment, with the main goal to restore/improve/arrest progression of clinical manifestations. The endoscopic endonasal route represents the master approach for lesions confined to the midline. Microsurgical transcranial and endoscopic transorbital approaches have a complementary role for addressing the lesion's component with large intracranial extension or affecting the paramedian aspect of the anterior cranial fossa and superior-lateral orbital compartment, respectively. The approach selection should be made case by case according to the tumor pattern of growth.

Location-based selection of the surgical approach to preserve the hippocampus in lesion-associated temporal lobe epilepsy

Background and objectivesSurgical resections for lesions associated with intractable temporal lobe epilepsy (TLE) offers good seizure outcomes.However, the necessity of hippocampectomy in addition to lesionectomy is controversial, especially when the hippocampus is not involved by the lesion. Lesionectomy alone, preserving the hippocampus by an appropriate surgical approach, might offer good seizure outcomes while maintaining neurocognitive function. In the present study, the aims were to examine the surgical strategy for lesions associated with TLE and to present how to select surgical approaches to preserve the hippocampus. MethodsA total of 22 consecutive lesion-associated TLE patients who underwent lesionectomy alone were retrospectively reviewed. The surgical approach, transsylvian, transorbital, subtemporal, supracerebellar transtentorial, or transcortical approach, was selected based on the location of the lesion. Postoperative seizure outcomes were classified by the Engel classification. Neurocognitive outcomes were assessed before and after surgery if possible. The pathology, the extent of resection, and lesion recurrence were reviewed. ResultsThe transsylvian approach was selected in six patients, the transorbital approach in one patient, the subtemporal approach in three patients, the supracerebellar transtentorial approach in five patients, and the transcortical approach in seven patients. Eighteen of 22 (81.8 %) patients achieved Engel’s class I or II good seizure outcomes. No patients had neurocognitive deterioration after surgery. Twelve patients had various types of brain tumors, and ten patients had non-tumorous lesions. Gross total resection was achieved in 21 patients. All patients had no recurrence. ConclusionFor patients with lesion-associated TLE, lesionectomy alone by the appropriate surgical approach offers satisfactory seizure outcomes while preserving hippocampus.

Transorbital Approach Clipping of Middle Cerebral Artery Aneurysm: A Virtual Reality Morphometric Anatomic Study

The transorbital approach (TOA) has a unique advantage to the more common lateral approaches as it provides direct access to the anterior middle fossa and medial sylvian fissure (SF) without significant dissection or retraction. However, when to use the TOA for surgical treatment of MCA aneurysms remains unclear. This study details the feasibility of clipping unruptured middle cerebral artery (MCA) aneurysms via the TOA by highlighting the anatomic features that either facilitate or hinder the approach. Virtual reality (VR) models of 25 MCA aneurysms from CT angiograms of actual patients were rendered with the relevant anatomic structures, including the neighboring temporal lobe and SF. TOA was performed on the models in VR and the globe was translated medially and inferiorly, replicating retraction used intraoperatively. Anatomic data, including the area of surgical freedom (AOF) at the aneurysm, were recorded. Trials of aneurysm clipping were conducted in VR and each aneurysm was classified as "possible" or "impossible" candidates for clipping via TOA. Separately, the relationship between surgical view and SF visualized was analyzed. Sixteen aneurysms were eliminated as candidates for TOA treatment either through VR clip trial and/or because the SF was inaccessible. The remaining 9 (36%) were candidates for TOA. Comparing the details of these two aneurysm categories with Mann Whitney U tests, there was a statistically significant difference in the AOF of the TOA approach and the width of the aneurysm dome. A clinical case report is also provided highlighting the VR rehearsal similarity with surgery. Given the minimally-invasive, technically-challenging approach, the feasibility and safety of TOA for MCA aneurysms must be evaluated before wide clinical adoption. This study identified AOF, aneurysm width, and SF accessibility as three features that may significantly impact the possibility of clipping MCA aneurysms via TOA.

Optimizing Management of Cavernous Sinus Meningiomas: A Novel Strategy Integrating Endoscopic Endonasal and Transorbital Surgery with Adjuvant Stereotactic Radiotherapy

Cavernous sinus meningiomas (CSMs) are challenging skull base tumors due to their proximity to vital neurovascular structures. Traditional aggressive transcranial resection often leads to significant morbidities with limited improvement of cranial nerve (CN) deficits. Recent advancements in endoscopic skull base surgery and stereotactic radiation therapy (SRT) offer a more conservative approach, facilitating tumor decompression while preserving critical structures. This retrospective study reviewed medical records of patients with symptomatic CSMs who underwent endoscopic endonasal and/or transorbital surgery, followed by adjuvant SRT, at our institution between January 2017 and April 2022. Patient demographics, tumor characteristics, surgical approaches, radiation, treatment outcomes, complications, and follow-up time were analyzed. Thirty-nine patients with CSMs were included. Endoscopic endonasal approach was performed in 24 patients (61.5%), endoscopic transorbital approach in 10 patients (25.6%), and combined approaches in 5 patients (12.8%). Adjuvant SRT was administered to 79.5% of patients. Postoperative outcomes showed recovery of CN 3-6 deficits and vision in 60.9% and 65% of cases, respectively. Complications included postoperative CN 3-6 deficits in 5 cases and postradiation visual deterioration in 1 case. During a mean follow-up period of 44months, tumor progression occurred in 4 patients (10.3%), with 3 diagnosed as World Health Organization grade II meningiomas and 1 as World Health Organization grade I. This study supports the use of endoscopic skull base surgery combined with adjuvant SRT for symptomatic CSMs, demonstrating both safety and efficacy. This approach yielded favorable outcomes in symptom improvement, tumor control, and positive safety profile.

Feasibility of Robotic Transorbital Surgery.

The transorbital approach (TOA) facilitates access to pathologies lateral to the optic nerve, a region that is difficult to access with an endonasal approach. In this study, we sought to investigate the feasibility of robotic-assisted surgery in lateral TOA. Six colored-silicon-injected human postmortem heads were prepared for dissection. The DaVinci Xi model was used with a 0-degree camera, 8 mm in diameter. A black diamond microforceps with an 8-mm diameter and 10-mm jaw length was used. The entry point of V1 (superior orbital fissure), V3 (foramen ovale), and posterior root of the trigeminal ganglion were chosen as the surgical targets. The length from the entry opening to each target point was measured. The angles formed between pairs of target points were measured to obtain the horizontal angle (root of the trigeminal ganglion-entry-V1) and the vertical angle (root of the trigeminal ganglion-entry-V3). Dissection was performed on 12 sides (6 specimens). The median distance from the entry point was 55 mm (range 50-58 mm) to the entry point of V1 (superior orbital fissure), 65 mm (range 57-70 mm) to the entry point of V3 (foramen ovale), and 76 mm (range 70-87 mm) to the root of the trigeminal ganglion. Meanwhile, the median of surgical angle between the entry point and the target was 19.1° (range 11.8-30.4°) on the horizontal angle and 16.5° (range 6.2-21.6°) on the vertical angle. This study found that application of lateral TOA in robotic-assisted surgery is premature because of the large size of the tool. However, although the entrance in lateral TOA is narrow, the internal surgical space is wide; this offers potential for design of appropriate surgical tools to allow increase tool usage.

Is It Time for a Paradigm Shift in the Surgical Management of Trigeminal Schwannomas? Evaluating the Role of the Transorbital Approach: An Anatomo-Clinical Study and Systematic Literature Review

BackgroundEndoscopic transorbital approach emerged in recent years as an effective, minimally invasive route to access Meckel’s cave area. Several case series proved its effectiveness in the surgical treatment of trigeminal schwannomas. Nonetheless, this route provides the advantages of a minimally invasive approach associated with low morbidity rates. In this anatomo-clinical study we illustrate the usefulness of the superior eyelid transorbital approach for the surgical treatment of trigeminal schwannoma guiding the clinical applicability of the anatomical findings into the real surgical practice. MethodsSuperior eyelid transorbital endoscopic approach was performed on eight cadaveric specimens, and the surgical results were confirmed in a retrospective review of all the surgical cases of transorbital surgery performed by the senior authors providing an illustrative case. Finally, we performed a literature review of all the case series of trigeminal schwannomas operated through an endoscopic transorbital approach. ResultsStepwise dissection was divided in 3 phases: skin, endo-orbital and endocranial. The illustrative case provided demonstrate gross total resection of a cavernous sinus type trigeminal schwannomas treated through this route. Literature review revealed 68 cases of trigeminal schwannomas that were successfully treated using the transorbital approach. ConclusionsThe endoscopic transorbital approach may offer a valuable alternative for the surgical treatment of trigeminal schwannomas. This technique provides a minimally invasive, direct and natural “interdural” route to the lateral wall of the cavernous sinus and Meckel's cave.

Microsurgical Resection of Trigeminal Schwannoma Through Transorbital Approach: 2-Dimensional Operative Video.

We present the case of an asymptomatic 34-year-old woman who was found to have an incidental left trigeminal schwannoma.1,2 Owing to the rapid increase in size on imaging, an atypical finding for this type of lesion,3 as well as the risk of cranial nerve involvement and need for tissue diagnosis, the patient underwent a microsurgical left transorbital approach with lateral orbitotomy to resect the lesion.4,5 Piecemeal resection was performed, and the internal contents of the cavernous sinus were preserved. Ultimately, gross total resection was achieved with no residual disease identified on postoperative imaging. No new neurologic deficits were noted after surgery. The technical considerations for the transorbital approach and the literature review on the outcomes for middle fossa lesions accessed by a lateral orbitotomy are reviewed.6-10 The patient consented to the procedure and to the publication of her images. Institutional Review Board approval was deemed unnecessary due to the retrospective, case-report nature of this work.

Endovascular approaches for the treatment of dural carotid-cavernous fistulas: A systematic review.

Dural carotid-cavernous fistulas (dCCFs), also known as indirect carotid-cavernous fistulas, represent abnormal connections between the arterial and venous systems within the cavernous sinus that are typically treated via endovascular approach. We aim to investigate the clinical characteristics of patients with dCCFs based on the endovascular treatment approach and assess angiographic and clinical outcomes. A systematic review of the literature was performed. Data including number of patients, demographics, presenting clinical symptoms, etiology of fistula, Barrow classification, and embolization material were collected and evaluated. Outcome measures collected included degree of fistula occlusion, postoperative symptoms, complications, and mean follow-up time. A total of 52 studies were included examining four primary endovascular approaches for treating dCCFs: transarterial, transfemoral-transvenous (transpetrosal or other), transorbital (percutaneous or via cutdown), and direct transfacial access. Overall data was collected from 736 patients with 817 dCCFs. Transarterial approaches exhibit lower dCCF occlusion rates (75.6%) compared to transvenous techniques via the inferior petrosal sinus (88.1%). The transorbital approach via direct puncture or surgical cutdown offers a more direct path to the cavernous sinus, although with greater complications including risk of orbital hematoma. The direct transfacial vein approach, though limited, shows up to 100% occlusion rates and minimal complications. We provide a comprehensive review of four main endovascular approaches for dCCFs. In summary, available endovascular treatment options for dCCFs have expanded and provide effective solutions with generally favorable outcomes. While the choice of approach depends on individual patient factors and technique availability, traditional transvenous procedures have emerged as the first-line endovascular treatment. There is growing, favorable literature on direct transorbital and transfacial approaches; however, more studies directly comparing these general transvenous options are necessary to refine treatment strategies.

Transorbital puncture for the treatment of cavernous sinus dural arteriovenous fistulas.

Endovascular embolization of carotid-cavernous sinus dural arteriovenous fistulas (CCFs) is most commonly performed via a transfemoral-transvenous approach. Surgical cut-down of the superior ophthalmic vein is an alternative, well-described route. When these prove inaccessible, a transorbital approach can be used to reach the fistula. We describe the recent experience- including indications, surgical technique, radiological findings and post-operative outcomes- in Melbourne of a series of patients in whom a percutaneous, transorbital direct puncture of the cavernous sinus enabled successful embolization of dural arteriovenous fistulas. Each of three patients achieved successful embolization of their CCFs via a transorbital puncture. Post-operatively, all patients experienced symptomatic relief with complete resolution of clinical signs secondary to their CCFs. When angioarchitecture does not allow endovascular access, transorbital puncture of carotid-cavernous sinus dural arteriovenous fistulas can be a safe and effective technique. This report supports its success and low complication rate.

Microsurgical Lateral Orbital Approaches to Resect Tumors within the Cavernous Sinus, Middle Fossa, and Temporal Lobe: A Systematic Review

Abstract Introduction Common approaches to remove skull base tumors invading the orbital apex, cavernous sinus, middle fossa, or temporal lobe include orbitozygomatic or fronto-orbital craniotomies. Recently, different types of orbital approaches have been described as alternative minimally invasive techniques. Objective With this systematic review, we analyzed the typology of intracranial tumors treated through transorbital approaches, especially through the lateral orbital (LO) wall, and analyzing the complication rates and outcomes. Design A PubMed/Medline search was performed using the criteria: “orbitotomy,” “transorbital,” “transpalpebral,” and “lateral orbitotomy” in combination with “cavernous sinus,” “middle fossa,” and “temporal lobe.” Main Outcome Measures From these reports, we collected diagnoses, lesion sizes and locations, approaches, outcomes, aesthetic outcomes, postoperative ptosis, postoperative cranial nerve (CN) palsies, length of CN deficits postoperatively, overall complications, and follow-up length. Results A total of 13 papers and 3 of our own cases matched our inclusion criteria totaling 160 patients. Most patients were treated for meningiomas (135, 84.4%). The approaches included the LO approach (n = 54; 33.8%), deep transorbital (n = 5; 3.1%), mini-LO (n = 91; 56.9%), and modified LO (n = 10; 6.2%). While not all cases reported excision success, the various LO approaches achieved total (n = 42; 26.25%) resection margins. Postoperative ocular complications (including CN palsies, proptosis, or ocular disturbances) totaled 46 (28.8%) new CN palsies, 23 (14.4%) occurrences of vision loss, 1 (1.7%) with worsened proptosis, 5 (3.9%) with worsened enophthalmos, and 42 (26.3%) other complications. Conclusion Microsurgical LO approaches, especially in the era of radiosurgery, may become a suitable alternative to other more established craniotomies.

Minimally Invasive Lateral Transorbital Approach for Clipping of Right Middle Cerebral Artery Aneurysm: 2-Dimensional Operative Video.

The lateral transorbital approach is a minimally invasive approach that was first described for accessing the cavernous sinus.1 Although other minimally invasive approaches have been broadly applied to aneurysm surgery,2 the use of transorbital keyholes for this is still quite rare.3,4 We present a 72-year-old man with an incidentally discovered 5-mm middle cerebral artery aneurysm. Despite a low rupture risk,5 the patient himself opted for treatment, and because of the complex shape of the aneurysm, he chose surgical clipping as the treatment of choice. Two unique aspects of the patient's anatomy brought forth transorbital approach for consideration. He had a wide fissure, which opened to the orbital wall, and a giant frontal sinus made its avoidance difficult with any anterolateral transcranial approach. The lateral transorbital approach was started with a transpalpebral incision.4,6,7 Both wings of the sphenoid bone were drilled until the frontal and temporal dura was exposed. Opening this through the orbit gained direct access to the large Sylvian fissure. Two specific challenges were specific to this opening: the aneurysm dome pointed straight at the surgeon, and the M1 segment, needed for proximal control, was directly behind the aneurysm. Despite these, the aneurysm was successfully eliminated through the transorbital approach with no residual or normal branch compromise. Given the specific anatomical provisions, the lateral transorbital approach was an effective and safety alternative to the pterional approach for middle cerebral artery aneurysms. No Institutional Review Board approval was sought or necessary as the patient provided consent for the procedure, publication of his image, and this submission.

Exploring optimal microscopic keyhole access to the skull base: an anatomical evaluation of transciliary supraorbital and transpalpebral orbitofrontal craniotomy approaches

Purpose: The past two decades have witnessed the rise of keyhole microscopic minimally invasive surgeries, including the transciliary supraorbital approach (TCA) and transpalpebral approach (TPA), commonly known as the transorbital approach. This study aims to elucidate the nuances, specific indications, and advantages of each approach. Methods: A series of dissections were conducted on five formalin-fixed, alcohol-preserved cadaver heads. The TCA was performed on one side, and the TPA on the other. Virtual measurements of working angles for both approaches were recorded. Additionally, three clinical cases were presented to illustrate the practical application of the techniques. Results: For TCA, the craniotomy dimensions were 1.7 cm x 2.5 cm (Cranial-Caudal (CC) x Lateral-Lateral (LL)), while for TPA, they measured 2.1 cm x 2.9 cm (CC x LL). The measurements of anterior clinoid processes (ACP) were obtained and compared between approaches. In the TCA, the mean ipsilateral ACP measurement was 62 mm (Range: 61 –63 mm), and the mean contralateral ACP measurement was 71.2 mm (Range: 70 –72 mm). In TPA, these measurements were 47.8 mm (Range: 47 –49 mm) and 62.8 mm (Range: 62 –64 mm), respectively. TCA exhibited an average cranial-caudal angle of 14.9°, while TPA demonstrated an average of 8.3°. Conclusion: The anterior cranial fossa was better exposed by a TCA, which also featured shorter operative times, enhanced midline visualization, and a quicker learning curve. Conversely, the middle fossa was better exposed by a TPA, making it an excellent option for middle fossa pathologies, including those in the anterior temporal lobe. After sphenoid bone wing drilling, the TPA offers superior visualization from the lateral to the medial aspect and enhances the CC angle. Additionally, the TPA reduces the risk of postoperative frontalis palsy based on anatomic landmarks. However, the TPA requires a greater cranial osteotomy, and due to unfamiliarity with eyelid anatomy, the learning curve for most neurosurgeons is lengthier for this procedure.

Navigating the Intersection Between the Orbit and the Skull Base: The "Mirror" McCarty Keyhole During Transorbital Approach: An Anatomic Study With Surgical Implications.

McCarty keyhole (MCK) is the most important entry point during orbitocranial and cranio-orbital approaches; nevertheless, its anatomic coordinates have never been detailedly described from transorbital perspective. To provide the spatial coordinates for intraorbital projection of the "mirror" MCK by using the well-established main anatomic-surgical bony landmarks met along transorbital corridor. MCK was identified in 15 adult dry skulls (30 sides) on exocranial surface of pterional region based on the well-defined external bony landmarks: on the frontosphenoid suture, 5 to 6 mm behind the joining point (JP) of frontozygomatic suture (FZS), frontosphenoid suture (FSS), and sphenozygomatic suture (SZS). A 1-mm burr hole was performed and progressively enlarged to identify the intracranial and intraorbital compartments. Exit site of the intraorbital part of burr hole was referenced to the FZS on the orbital rim, the superior orbital fissure, and the inferior orbital fissure and to the JP of FZS, FSS, and SZS. To electronically validate the results, 3-dimensional photorealistic and interactive models were reconstructed with photogrammetry. Finally, for a further validation, McCarty mirror keyhole was also exposed, based on results achieved, through endoscopic transorbital approach in 10 head specimens (20 sides). Intraorbital projection of MCK was identified on the FSS on intraorbital surface, 1.5 ± 0.5 mm posterior to JP, 11.5 ± 1.1 mm posterior to the FZS on orbital rim following the suture, 13.0 ± 1.2 mm from most anterior end of superior orbital fissure, 15.5 ± 1.4 mm from the most anterior end of the inferior orbital fissure in vertical line, on measurements under direct macroscopic visualization (mean ± SD). These values were electronically confirmed on the photogrammetric models with mean difference within 1 mm. To be aware of exact position of intraorbital projection of MCK during an early stage of transorbital approaches provides several surgical, clinical, and aesthetic advantages.

Endoscopic Transorbital Resection of Temporal Pole Cavernoma: 2-Dimensional Operative Video.

An endoscopic transorbital approach has been recently included in the neurosurgical armamentarium.1 We present a case of a 31-year-old female patient with a history of recent-onset refractory epilepsy related to a left temporal pole cavernoma operated through a superior eyelid endoscopic transorbital approach. The operative video shows the key surgical steps to ensure optimal surgical freedom, adequate exposure, and complete tumor resection.2 The postoperative course was uneventful, and the patient obtained seizure control and good cosmetic results without postoperative complications. The brain computed tomography and MRI showed the size of bone removal and confirmed the complete removal of the lesion, respectively. At 3-month follow-up, the patient is epileptic seizures-free without medications. An endoscopic transorbital approach provides adequate exposure of the temporal pole, allowing safe tumor resection. Complication avoidance encompasses careful dissection of palpebral muscles, dynamic orbital retraction, and neuronavigation guidance; sphenoidal drilling according to key anatomic landmarks (eg, sagittal crest3); and anatomic knowledge of the cavernous sinus and internal carotid artery and its tributaries course from a transorbital perspective4 and reconstruction filling the empty spaces using fat, fascia lata, or dural substitutes. All procedures performed were approved by the ethics committee of both centers and in accordance with Declaration of Helsinki and its later amendments. The patient consented to the procedure and to the publication of her images, and appropriate consent was obtained for publication of cadaveric images.

Commentary: Transorbital approach to the cavernous sinus: an anatomical study of the related cranial nerves.

Commentary: Transorbital approach to the cavernous sinus: an anatomical study of the related cranial nerves.

Endoscopic trans-orbital approach for the tumor-related epilepsy at the temporal tip.

Minimally invasive surgery is gaining increasing interest in epilepsy surgery. In this video, the authors present the endoscopic transorbital approach for an epileptogenic lesion located at the temporal tip. The patient was a man in his 40s who has had intractable focal impaired awareness seizures and focal to bilateral tonic-clonic seizures since he was 31 years of age. According to the preoperative examination, including stereotactic electroencephalography, a cavernous angioma located at the tip of the right temporal lobe was diagnosed as an epileptogenic lesion. Lesionectomy for this lesion was performed using the endoscopic transorbital approach as minimally invasive surgery and a favorable outcome was achieved. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2414.

Minimally invasive orbito-zygomatic access for cranio-orbital hyperostotic meningiomas. Case report

Application into clinical practice of a minimally invasive surgical approach to the removal of hyperostotic cranioorbital meningiomas. This publication is based on the analysis of a clinical case of 49-year-old woman with exophthalmos, and the absence of neurological deficits. A non-standard approach to remove a cranio-orbital hyperostotic meningioma through a minimally invasive orbito-zygomatic approach was used. The main principle of proposed surgical approach was to remove first the hyperostosis, followed by the areas of dura mater involved by the tumor, according to the "outside-in" principle. According to the intraoperative process and the results of MRI control, it was possible to achieve total removal of both the affected dura mater and the hyperostotic lesion. The minimally invasive transorbital approach opens a wide corridor for surgery of the para and retroorbital space and allows using the "outside-in" method, to remove not only hyperostosis but also the area of damage to the dura mater.