No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Transorbital endoscopic assisted resection of a superior orbital fissure cavernous haemangioma: a technical case report
Abstract
Superior orbital fissure and orbital apex lesions are challenging to manage, regardless of the approach chosen, due to the potential morbidity. The objectives of this study are to describe an innovative, minimally invasive surgical approach addressing this critical area and to discuss its indications and outcomes.
A young patient presented with visual disturbances (reduction of color discrimination, central scotoma) and mild exophthalmos owing to the presence of a right orbital apex cavernous haemangioma with superior orbital fissure invasion.
The lesion was removed via a minimally invasive, neuronavigated, transorbital superior eyelid endoscopic-assisted approach.
Technical feasibility and safety, early and late complications, length of hospitalization time and follow-up data were collected and analyzed.
The lesion was radically resected minimizing the surgical morbidity and hospitalization time for the patient and with encouraging functional and cosmetic outcomes. No recurrences were observed 1 year after surgery.
The endoscopic-assisted transorbital approach should be considered a safe and effective option that can be applied in the treatment of lesions affecting such complex anatomical regions, as it offers excellent visualization of the surgical field, acceptable sequelae and reduced morbidity in relation to the traditional transcranial/transfacial approaches. Further studies and larger case series are needed in order to validate the reproducibility and range of applications of this surgical technique.
... Other symptoms include visual acuity impairment or visual field disturbances, oculomotor impairment, pressure sensation and pain. CVMs' behaviour may be very different: some remain stable for several years, while others grow more rapidly; nonetheless, spontaneous orbital haemorrhage secondary to CVM rupture is very rare (10). ...
... Furthermore, the efforts in cadaveric anatomical studies have opened the way to the expand its indications: this approach became a valid alternative to expose anterior and middle cranial fossae through different transorbital corridors, for the removal of a variety of skull base lesions (27,28). Dallan et al reported the endoscopic eyelid approach as surgical option for the removal of an intraconal CVM of the orbital apex and for the management of 9 different superior-lateral intraorbital lesions (10,29,30). The inner features of CVMs make their removal through endoscopic approaches favorable, being usually well encapsulated and easy to dissect from the orbital fat and surrounding intraorbital structures. ...
... This technique provides an excellent exposure over the lateral and superior aspects of the orbit, including both extraconal and intraconal compartments, and allows several advantages, i.e. excellent illumination and visualization, short and direct route to the target, avoidance of bony and muscles manipulation with minimal damage to normal structures. Furthermore, low complication rates, less discomfort, better cosmetic results, and shorter hospitalization for patient are reported (10). ...
Cavernous venous malformations (CVMs) are one of the most common benign primary orbital lesions in adults and the second most frequent cause of unilateral proptosis. Extraconal location is extremely rare, representing a favorable condition as compared to intraconal, as lesions at this level often adhere to orbital muscles and optic nerve. Herein, we report the case of a 50-year-old patient, who came to our attention because of progressive painless right axial proptosis. Magnetic resonance images were consistent with an extraconal CVM, occupying the superior temporal compartment of the orbit. Successful removal of the lesion was achieved through an endoscopic transorbital eyelid approach. The present case confirms the safety and efficacy of the endoscopic transorbital eyelid approach.
... been used over the years including, more recently, endoscopic approaches either performed through the endonasal corridor or the transorbital pathway. 1,2,4,10,14,16,[25][26][27][28]50 The endoscopic endonasal route is currently gaining favor as a viable surgical technique to achieve optic nerve decompression, because it provides a minimally invasive, adequate exposure of the optic canal. 1,4,27,32 Furthermore, the corridor itself provides excellent visualization of the medial aspect of the orbital apex while avoiding brain retraction and olfactory bulb injuries as can happen in transcranial approaches. ...
... Among the transcranial approaches, the trans-and supraorbital approaches have been introduced as feasible lateral surgical trajectories for accessing the optic canal and the anterior and middle skull base. 5,6,12,16,33,40,45,47 More recently, the superior eyelid transorbital approach, with the aid of the endoscope, has been proposed as a possible minimally invasive ventral access to selected areas of the anterior and middle cranial fossae, 31 allowing exposure of the optic nerve from above and laterally. 31 Furthermore, this latter route does not require the removal of the orbital rim or the frontal bone convexity, also avoiding brain manipulation. ...
... Data from the literature show that trans-and supraorbital approaches have recently become an option for accessing the anterior and middle skull base via a lateral trajectory. 5,6,12,16,33,39,40,47 Thirty years ago, Call 8 was the first to describe optic nerve decompression through a transorbital approach in a case series of 8 patients. Afterward, the widespread acceptance of endoscopic skull base surgery for the management of different skull base pathologies pushed the development of new strategies and the refinement of existing ones, that is, the transorbital route. ...
OBJECTIVE
Different surgical routes have been used over the years to achieve adequate decompression of the optic nerve in its canal including, more recently, endoscopic approaches performed either through the endonasal corridor or the transorbital one. The present study aimed to detail and quantify the amount of bone removal around the optic canal, achievable via medial-to-lateral endonasal and lateral-to-medial transorbital endoscopic trajectories.
METHODS
Five human cadaveric heads (10 sides) were dissected at the Laboratory of Surgical Neuroanatomy of the University of Barcelona (Spain). The laboratory rehearsals were run as follows: 1) preliminary preoperative CT scans of each specimen, 2) anatomical endoscopic endonasal and transorbital dissections and Dextroscope-based morphometric analysis, and 3) quantitative analysis of optic canal bone removal for both endonasal and transorbital endoscopic approaches.
RESULTS
The endoscopic endonasal route permitted exposure and removal of the most inferomedial portion of the optic canal (an average of 168°), whereas the transorbital pathway allowed good control of its superolateral part (an average of 192°). Considering the total circumference of the optic canal (360°), the transorbital route enabled removal of a mean of 53.3% of bone, mainly the superolateral portion. The endonasal approach provided bone removal of a mean of 46.7% of the inferomedial aspect. This result was found to be statistically significant (p < 0.05). The morphometric analysis performed with the aid of the Dextroscope (a virtual reality environment) showed that the simulation of the transorbital trajectory may provide a shorter surgical corridor with a wider angle of approach (39.6 mm; 46.8°) compared with the simulation of the endonasal pathway (52.9 mm; 23.8°).
CONCLUSIONS
Used together, these 2 endoscopic surgical paths (endonasal and transorbital) may allow a 360° decompression of the optic nerve. To the best of the authors' knowledge, this is the first anatomical study on transorbital optic nerve decompression to show its feasibility. Further studies and, eventually, surgical case series are mandatory to confirm the effectiveness of these approaches, thereby refining the proper indications for each of them.
... Although these lesions tend not to infiltrate into local tissue, they are capable of incorporating adjacent blood vessels and nerves into their capsule as they expand. 13 Histologically, OCHs demonstrate features of slow-growing venous lesions with mature cellular components that do not tend toward dysplasia or hypercellularity. Based on the classification of the International Society for the Study of Vascular Anomalies (ISSVA), these lesions should be characterized as slow-flow cavernous venous malformations. ...
... As endoscopic skull base techniques have become more widely utilized and accepted, however, approaches to the orbit have experienced a rebirth, with an increasing number of papers being published on the subject in recent years. 13,17 Consequently, this study was conceived in an effort to examine the independent endoscopic techniques developed at multiple experienced institutions to deal with a single type of lesion. The preoperative workup for OCH was found to be similar among all groups. ...
... This is consistent with the fact that OCHs tend to be well encapsulated and rarely infiltrate adjacent structures. 13 As expected, tumors located within the intraconal space were associated with a greater incidence of incomplete removal and postoperative morbidity including new onset diplopia and enophthalmos. This may be attributed to the fact that approaches to the intraconal space mandate a larger orbitotomy as well as a greater degree of medial rectus instrumentation than extraconal lesions. ...
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.
... Endoscopicassisted not transnasal but transorbital approaches are quite neglected although transcutaneous orbital endoscopic surgery was pioneered and described in the early 80's (5) . Actually very few data concerning this surgical option are reported in literature (1,6,7) , and the number of cases collected is really limited. ...
... Actually, non-transnasal endoscopic assisted approaches inside and around the orbit are quite neglected, with very few exceptions (6,7,16,17) . Given our widespread experience in balanced orbital decompression for Graves disease (18) as well as in endoscopic skull base surgery and transnasal intraorbital approaches (2)(3)(4) , we started to manage selected intraorbital lesions via a superior eyelid approach, under endoscopic assistance. ...
Background: The management of intraorbital lesions is challenging and it is strongly dependent to their nature, position and biological behaviour. Traditionally, the superior and lateral compartments of the orbit are addressed via lateral orbitotomy or transcranial approaches. Herein we present our preliminary experience in the management of selected supero-lateral intraorbital lesion through an endoscopic-assisted superior-eyelid approach. Methodology: All cases of intraorbital lesion treated in two Italian tertiary care referral centres using a superior eyelid endoscopic-assisted transorbital approach were retrospectively reviewed. Results: Nine patients have been analysed. The aim of surgery was diagnostic in 5 cases and curative in the remaining 4 patients. Significant tissue biopsy was obtained in all the five diagnostic procedures. Complete resection was obtained in 3/4 lesions. No major intra- or postoperative complications have been observed. Mean surgical time was 68 minutes. Mean hospitalization time was 4.4 days. All patients were satisfied about the surgical procedure, as emerged by the post-operative counselling. At present, the mean follow-up time is 18 months, ranging from 11 to 25 months. Conclusions: Our preliminary results are promising with successful functional and cosmetic outcomes and reduced morbidity for the patient. This approach should be considered as an option for selected intraorbital lesions.
... Endoscopicassisted not transnasal but transorbital approaches are quite neglected although transcutaneous orbital endoscopic surgery was pioneered and described in the early 80's (5) . Actually very C o r r e c t e d p r o o f few data concerning this surgical option are reported in literature (1,6,7) , and the number of cases collected is really limited. ...
... Actually, non-transnasal endoscopic assisted approaches inside and around the orbit are quite neglected, with very few exceptions (6,7,16,17) . Given our widespread experience in balanced orbital decompression for Graves disease (18) as well as in endoscopic skull base surgery and transnasal intraorbital approaches (2)(3)(4) , we started to manage selected intraorbital lesions via a superior eyelid approach, under endoscopic assistance. ...
Background:
The management of intraorbital lesions is challenging and it is strongly dependent to their nature, position and biological behaviour. Traditionally, the superior and lateral compartments of the orbit are addressed via lateral orbitotomy or transcranial approaches. Herein we present our preliminary experience in the management of selected supero-lateral intraorbital lesion through an endoscopic-assisted superior-eyelid approach.
Methodology:
All cases of intraorbital lesion treated in two Italian tertiary care referral centres using a superior eyelid endoscopic-assisted transorbital approach were retrospectively reviewed.
Results:
Nine patients have been analysed. The aim of surgery was diagnostic in 5 cases and curative in the remaining 4 patients. Significant tissue biopsy was obtained in all the five diagnostic procedures. Complete resection was obtained in 3/4 lesions. No major intra- or postoperative complications have been observed. Mean surgical time was 68 minutes. Mean hospitalization time was 4.4 days. All patients were satisfied about the surgical procedure, as emerged by the post-operative counselling. At present, the mean follow-up time is 18 months, ranging from 11 to 25 months.
Conclusions:
Our preliminary results are promising with successful functional and cosmetic outcomes and reduced morbidity for the patient. This approach should be considered as an option for selected intraorbital lesions.
... A reported case in the literature described the successful treatment of an extraconal CVM using this approach. The noted advantages included excellent exposure of both extraconal and intraconal compartments, superior illumination and visualization, a direct and efficient route to the target, and minimized manipulation of bone and muscle, thereby reducing damage to normal structures [18,19]. ...
The transorbital approach (TOA) is gaining popularity in skull base surgery scenarios. This approach represents a valuable surgical corridor to access various compartments and safely address several intracranial pathologies, both intradurally and extradurally, including tumors of the olfactory groove in the anterior cranial fossa (ACF), cavernous sinus in the middle cranial fossa (MCF), and the cerebellopontine angle in the posterior cranial fossa (PCF). The TOA exists in many variants, both from the point of view of invasiveness and from that of the entry point to the orbit, corresponding to the four orbital quadrants: the superior eyelid crease (SLC), the precaruncular (PC), the lateral retrocanthal (LRC), and the preseptal lower eyelid (PS). Moreover, multiportal variants, consisting of the combination of the transorbital approach with others, exist and are relevant to reach peculiar surgical territories. The significance of the TOA in neurosurgery, coupled with the dearth of thorough studies assessing its various applications and adaptations, underscores the necessity for this research. This extensive review delineates the multitude of target lesions reachable through the transorbital route, categorizing them based on surgical complexity. Furthermore, it provides an overview of the different transorbital variations, both standalone and in conjunction with other techniques. By offering a comprehensive understanding, this study aims to enhance awareness and knowledge regarding the current utility of the transorbital approach in neurosurgery. Additionally, it aims to steer future investigations toward deeper exploration, refinement, and exploration of additional perspectives concerning this surgical method.
... The course of CVM can be different: some remain stable for several years, while others increase more rapidly; however, spontaneous orbital haemorrhage secondary to CVM rupture is very rare [57]. ...
Thyroid orbitopathy (TO) is the most common cause of orbital tissue inflammation, accounting for about 60% of all orbital inflammations. The inflammatory activity and severity of TO should be diagnosed based on personal experience and according to standard diagnostic criteria. Magnetic resonance imaging (MRI) of the orbit is used not only to identify swelling and to differentiate inflammatory active from non-active TO, but also to exclude other pathologies, such as orbital tumours or vascular lesions. However, a group of diseases can mimic the clinical manifestations of TO, leading to serious diagnostic difficulties, especially when the patient has previously been diagnosed with a thyroid disorder. Diagnostic problems can be presented by cases of unilateral TO, unilateral or bilateral TO in patients with no previous or concomitant symptoms of thyroid disorders, lack of symptoms of eyelid retraction, divergent strabismus, diplopia as the only symptom of the disease, and history of increasing diplopia at the end of the day. The lack of visible efficacy of ongoing immunosuppressive treatment should also raise caution and lead to a differential diagnosis of TO. Differential diagnosis of TO and evaluation of its activity includes conditions leading to redness and/or swelling of the conjunctiva and/or eyelids, and other causes of ocular motility disorders and eye-setting disorders. In this paper, the authors review the most common diseases that can mimic TO or falsify the assessment of inflammatory activity of TO.
... The endoscopic trans-orbital approach [11,12] has also been used to approach trigeminal schwannomas within Meckel's cave [59]. This approach is in the antero-lateral corridor and offers a shorter trajectory to Meckel's cave than the EEA approach. ...
Background
Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations.
Methods
A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the second of a three-part series describing non-vestibular schwannomas (V, VII).
Results
A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to pre-operative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies, and follow-up management.
Conclusion
This article represents the consensually derived opinion of the task force with respect to the treatment of trigeminal and facial schwannoma. The aim of treatment is maximal safe resection with preservation of function. Careful thought is required to select the appropriate surgical approach. Most middle fossa trigeminal schwannoma tumours can be safely accessed by a subtemporal extradural middle fossa approach. The treatment of facial nerve schwannoma remains controversial.
... Dallan et al. have described novel endoscopic transorbital approaches to various orbital, superior orbital fissure, and cavernous sinus lesions. [20][21][22][23] Lubbe et al. have proposed the concept of multiportal surgery which includes a combination of transnasal and supraorbital approach to lesions of ACF. [8] In our case, we have undertaken a TONES approach to remove the fracture fragments of the orbital roof which were impinging on the superior rectus muscle. ...
The transorbital neuroendoscopic surgery (TONES), endoscopic transnasal skull base procedures, and the concept of multiportal minimal access neurosurgery are novel, rapidly evolving approaches in the management of complex skull base lesions. A 27-year-old male presented with a history of road traffic accident with nasal bleed, cerebrospinal fluid (CSF) rhinorrhea, and left eye deformity. There was left upper eyelid ecchymosis, orbital dystopia, left pupil was dilated, and fixed with no extraocular movements. The computed tomography scan showed basifrontal contusion and complex comminuted anterior cranial fossa (ACF) fracture involving left cribriform plate and left orbital roof with fracture fragment impinging on the superior rectus muscle with suspicious orbital CSF leak. There was no improvement with conservative management. Hence, a novel combined TONES, transnasal endoscopic multiportal surgery was undertaken for the removal of fracture fragments and multi-layered closure of the complex ACF defect. The patient had a complete resolution of orbital dystopia and visual loss with no evidence of CSF leak postoperatively.
... Transorbital endoscopic approaches (TEA) have been surmised to provide a direct toute to the lateral portion of the SB. Consequently, they have been adopted with increasing frequency to resect SB lesions over the last decade [13,15,19,25,47,48,55,57]. ...
Transorbital endoscopic approaches are increasing in popularity as they provide corridors to reach various areas of the ventral skull base through the orbit. They can be used either alone or in combination with different approaches when dealing with the pathologies of the skull base. The objective of the current study is to evaluate the surgical anatomy of transorbital endoscopic approaches by cadaver dissections as well as providing objective clinical data on their actual employment and morbidity through a systematic review of the current literature. Four cadaveric specimens were dissected, and step-by-step dissection of each endoscopic transorbital approach was performed to identify the main anatomic landmarks and corridors. A systematic review with pooled analysis of the current literature from January 2000 to April 2020 was performed and the related studies were analyzed. Main anatomical landmarks are presented based on the anatomical study and systematic review of the literature. With emphasis on the specific transorbital approach used, indications, surgical technique, and complications are reviewed through the systematic review of 42 studies (19 in vivo and 23 anatomical dissections) including 193 patients. In conclusion, transorbital endoscopic approaches are promising and appear as feasible techniques for the surgical treatment of skull base lesions. Surgical anatomy of transorbital endoscopic approaches can be mastered through knowledge of a number of anatomical landmarks. Based on data available in the literature, transorbital endoscopic approaches represent an important complementary that should be included in the armamentarium of a skull base team.
... Однако опыт проведения орбитальной декомпрессии при эндокринной офтальмопатии свидетельствует об отсутствии серьезных проблем при использовании данной техники благодаря периодической релаксации глазного яблока [19,20]. Кроме того, безопасность трансорбитальных доступов была подтверждена при эндоскопических операциях, когда содержимое орбиты намного более управляемо благодаря вскрытию периорбиты и поэтапной внутриорбитальной диссекции [18,21,22]. Среди возможных недостатков этого подхода можно отметить незнакомство большинства хирургов с трансорбитальными эндоскопическими доступами (а следовательно, им требуется некоторое время, чтобы овладеть новыми практическими навыками), а также необходимость ориентироваться в двухмерном эндоскопическом пространстве. ...
... For this reason, before performing this type of surgery, a careful study of the case with the various specialists involved is mandatory. 18 A skull base team focused on orbital pathology should include specialists such as otolaryngologists, neurosurgeons, and ophthalmologists. They have a fundamental role which is not limited to the operating theater but crucial during the pre-and postoperative evaluation and also for nonsurgical therapy. ...
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.
... Recently, the endoscopic transorbital approach (eTOA) with a superior eyelid incision has emerged as a minimally invasive technique, which introduces a lateral approach to the orbit. [2][3][4][5][6] This approach can provide an additional surgical corridor into the anterior and middle cranial fossas and has the following advantages: it reduces the scar length, prevents excessive retraction of the temporalis muscle, and leaves a smaller cranial bone defect. However, it is still unknown which types of meningiomas can be optimally treated with this novel surgical approach. ...
OBJECTIVE
Spheno-orbital meningiomas (SOMs) are complicated tumors that involve multiple structures at initial presentation, such as the orbit, temporalis muscle, sphenoidal bone, cavernous sinus, and temporal or infratemporal fossa. The infiltrative growth and complexity of this type of meningioma make total resection impossible. In this study, the authors evaluated the surgical outcome of the endoscopic transorbital approach (eTOA) for SOM. In addition, they identified optimal indications for the use of eTOA and analyzed the feasibility of this approach as a minimally invasive surgery for SOMs of varying types and locations at presentation.
METHODS
Between September 2016 and December 2019, the authors performed eTOA in 41 patients with SOM with or without orbital involvement at 3 independent tertiary institutions. The authors evaluated the surgical outcomes of eTOA for SOM and investigated several factors that affect the outcome, such as tumor volume, tumor location, and the presence of lateral orbitotomy. Gross-total resection (GTR) was defined as complete resection of the tumor or intended subtotal resection except the cavernous sinus. This study was undertaken as a multicenter project (006) of the Korean Society of Endoscopic Neurosurgery (KOSEN-006).
RESULTS
There were 41 patients (5 men and 36 women) with a median age of 52.0 years (range 24–73 years). Twenty-one patients had tumors that involved the orbital structure, while 14 patients had tumors that presented at the sphenoidal bone along with other structures, such as the cavernous sinus, temporal fossa, and infratemporal fossa. Fifteen patients had the globulous type of tumor and 26 patients had the en plaque type. Overall, GTR was achieved in 21 of 41 patients (51.2%), and complications included CSF leaks in 2 patients and wound complications in 2 patients. Multiple logistic regression analysis showed that the en plaque type of tumor, absence of lateral orbital rim osteotomy, involvement of the temporal floor or infratemporal fossa, and involvement of the orbit and medial one-third of the greater sphenoidal wing were closely associated with lower GTR rates (p < 0.05). Multivariate analysis revealed that the en plaque type of tumor and the absence of lateral orbital rim osteotomy were significant predictors for lower GTR rate.
CONCLUSIONS
The en plaque type of SOM remains a challenge despite advances in technique such as minimally invasive surgery. Overall, clinical outcome of eTOA for SOM was comparable to the transcranial surgery. To achieve GTR, eTOA is recommended, with additional lateral orbital rim osteotomy for globulous-type tumors, without involving the floor of the temporal and infratemporal fossa.
... The inclusion of endoscopic surgery in graduate medical education curricula has led to increased surgeon facility with operating through smaller keyholes and corridors, and the literature in recent years has seen an increase in case series [45,46] and cadaveric anatomic feasibility studies highlighting creative transorbital approaches to the sphenoid wing [47,48], anterior and middle cranial fossae [49], the cavernous sinus [50][51][52], Meckel's cave [53,54] and other intracranial structures adjacent to the orbit [55]. Further, with the advent of intraoperative stereotactic neuro-navigation, accessing deeper structures via the transorbital route may be made even safer. ...
IntroductionThe orbital contents, afferent and efferent visual pathways, and the cranial nerves involved in eye movement, corneal sensation and eyelid closure traverse the skull base, a region bounded by the intracranial cavity, the paranasal sinuses, and the deep spaces of the face and head. As such, tumors from above or below have potential to affect some aspect of the visual system.Methods
We discuss here the clinical ophthalmologic and orbital considerations in the evaluation of patients with these tumors, as well as the ophthalmic sequelae of treatment with radiation or surgery (or both). And for the surgeon, we discuss the ophthalmic and orbital considerations in surgical planning, the role of the orbital surgeon in skull base surgery, and briefly discuss transorbital approaches to the skull base.Results and conclusionOphthalmic and orbital dysfunction may be the main source of disability in patients with skull base malignancy; it is thus incumbent on those who manage patients with tumors of this region to be aware of the ophthalmic, neuro-ophthalmic and orbital manifestations, so as to best tailor therapy and monitor treatment outcomes.
... 30 Its superior eyelid skin incision offers the advantage of being hidden when the patient's eyes are open, provides dissection in natural anatomical planes, and affords preservation of the temporalis muscle, thus facilitating an acceptable cosmetic outcome, as described in initial surgical experiences and anatomical reports. 2,9,13,15 With no dedicated study that addressed a schematic classification of the intracranial structures approached via this novel route, we undertook the anatomical analysis presented in this paper in order to determine the applicability of the various transorbital routes to the neurosurgical pathologies of the anterior and middle cranial fossae. Using anatomical landmarks in relation to the orbital contents, we built a modular approach that was defined by discrete corridors and further separated these into lateral (i.e., lateral to the superior and inferior orbital fissures) and medial (i.e., extension medial to the superior and inferior orbital fissures) corridors. ...
BACKGROUND
Various extensions of the supraorbital approach reach the lateral and parasellar middle cranial fossa regions by removing the orbital rim and greater/lesser sphenoid wings. Recent proposals of a purely endoscopic ventral transorbital pathway to these regions heighten the need to compare these surgical windows.
OBJECTIVE
To detail the lateral and parasellar middle cranial fossa regions and quantify exposures by 2 surgical windows (transcranial and transorbital) through anatomic study.
METHODS
In 5 cadaveric specimens (10 sides), dissections consisted of 3 stages: stage 1 began with the supraorbital approach via the eyebrow; stage 2, endo-orbital approach via the superior eyelid, continued with removal of lesser and greater sphenoid wings; and stage 3, extended supraorbital, re-evaluated the gains of stage 2 from the perspective of stage 1. Operative working areas were quantified in Sylvian, anterolateral temporal, and parasellar regions; bone removal volumes were measured at each stage (nonpaired Student t-test).
RESULTS
Visualization into the anterolateral temporal and Sylvian areas, though varied in perspective, were comparable with either eyelid or transcranial routes. Compared with transcranial views through a supraorbital window, the eyelid approach significantly increased exposure in the parasellar region with wider angle of attack (P < .01) and achieved comparable bone removal volumes.
CONCLUSION
Stage 2’s unique anatomic view of the lateral and parasellar middle cranial fossa regions paves the way for possible surgical application to select pathologies typically treated via transcranial approaches. Disadvantages may be the surgeon's unfamiliarity with the anatomy of this purely endoscopic, ventral route and difficulties of dural and orbital repair.
... 30 Its superior eyelid skin incision offers the advantage of being hidden when the patient's eyes are open, provides dissection in natural anatomical planes, and affords preservation of the temporalis muscle, thus facilitating an acceptable cosmetic outcome, as described in initial surgical experiences and anatomical reports. 2,9,13,15 With no dedicated study that addressed a schematic classification of the intracranial structures approached via this novel route, we undertook the anatomical analysis presented in this paper in order to determine the applicability of the various transorbital routes to the neurosurgical pathologies of the anterior and middle cranial fossae. Using anatomical landmarks in relation to the orbital contents, we built a modular approach that was defined by discrete corridors and further separated these into lateral (i.e., lateral to the superior and inferior orbital fissures) and medial (i.e., extension medial to the superior and inferior orbital fissures) corridors. ...
OBJECTIVE
Recent studies have proposed the superior eyelid endoscopic transorbital approach as a new minimally invasive route to access orbital lesions, mostly in otolaryngology and maxillofacial surgeries. The authors undertook this anatomical study in order to contribute a neurosurgical perspective, exploring the anterior and middle cranial fossa areas through this purely endoscopic transorbital trajectory.METHODS
Anatomical dissections were performed in 10 human cadaveric heads (20 sides) using 0° and 30° endoscopes. A step-by-step description of the superior eyelid transorbital endoscopic route and surgically oriented classification are provided.RESULTSThe authors' cadaveric prosection of this approach defined 3 modular routes that could be combined. Two corridors using bone removal lateral to the superior and inferior orbital fissures exposed the middle and anterior cranial fossa (lateral orbital corridors to the anterior and middle cranial base) to unveil the temporal pole region, lateral wall of the cavernous sinus, middle cranial fossa floor, and frontobasal area (i.e., orbital and recti gyri of the frontal lobe). Combined, these 2 corridors exposed the lateral aspect of the lesser sphenoid wing with the Sylvian region (combined lateral orbital corridor to the anterior and middle cranial fossa, with lesser sphenoid wing removal). The medial corridor, with extension of bone removal medially to the superior and inferior orbital fissure, afforded exposure of the opticocarotid area (medial orbital corridor to the opticocarotid area).CONCLUSIONS
Along with its minimally invasive nature, the superior eyelid transorbital approach allows good visualization and manipulation of anatomical structures mainly located in the anterior and middle cranial fossae (i.e., lateral to the superior and inferior orbital fissures). The visualization and management of the opticocarotid region medial to the superior orbital fissure are more complex. Further studies are needed to prove clinical applications of this relatively novel surgical pathway.
... 45 Moreover, a recent report described the endoscopic-assisted transorbital approach for superior orbital fissure and orbital apex lesions. 18 Acute orbital cellulitis, diplopia, and enophthalmos are reported complications of this surgical procedure. ...
The cavernous venous malformation (CVM) of the orbit, previously called cavernous hemangioma, is the most common primary orbital lesion of adults. CVM occurs more often in women and typically presents in the fourth and fifth decades of life. It is a benign vascular malformation characterized by a well-defined capsule and numerous large vascular channels. The most common sign of CVM is progressive axial proptosis from the preferential involvement of the intraconal orbital space. Optic nerve damage and other signs of orbital pathology may be present, with a variable degree of visual impairment. The combination of ultrasound, computed tomography, and magnetic resonance imaging leads to an accurate diagnosis in the vast majority of cases. Surgical and non-surgical treatments are required in case of symptomatic lesions, with a characteristic multidisciplinary management influencing optimal outcome. Orbitotomy represents the traditional surgical approach. Recently, the endoscopic transnasal approach to the orbital cavity has gained interest, representing a feasible and safe, less invasive surgical technique for the management of CVM.
... Finally, regarding the issue of the transorbital route for intracranial pathology, it should be stressed that at present this kind of approach is still in its infancy, so we have to await further developments, in terms of both surgical technique and surgical tools, to reach proper conclusions. [10][11][12] Above all, the present work has been designed to provide useful anatomical details with regard to the transorbital approach. A peer understanding of the anatomy represents the backbone of any surgical procedure; we aimed to detail the main features of the MOB as the key landmark in identification of the cavernous sinus. ...
OBJECTIVE
Exposure of the cavernous sinus is technically challenging. The most common surgical approaches use well-known variations of the standard frontotemporal craniotomy. In this paper the authors describe a novel ventral route that enters the lateral wall of the cavernous sinus through an interdural corridor that includes the removal of the greater sphenoid wing via a purely endoscopic transorbital pathway.
METHODS
Five human cadaveric heads (10 sides) were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. To expose the lateral wall of the cavernous sinus, a superior eyelid endoscopic transorbital approach was performed and the anterior portion of the greater sphenoid wing was removed. The meningo-orbital band was exposed as the key starting point for revealing the cavernous sinus and its contents in a minimally invasive interdural fashion.
RESULTS
This endoscopic transorbital approach, with partial removal of the greater sphenoid wing followed by a “natural” ventral interdural dissection of the meningo-orbital band, allowed exposure of the entire lateral wall of the cavernous sinus up to the plexiform portion of the trigeminal root and the petrous bone posteriorly and the foramen spinosum, with the middle meningeal artery, laterally.
CONCLUSIONS
The purely endoscopic transorbital approach through the meningo-orbital band provides a direct view of the cavernous sinus through a simple and rapid means of access. Indeed, this interdural pathway lies in the same sagittal plane as the lateral wall of the cavernous sinus. Advantages include a favorable angle of attack, minimal brain retraction, and the possibility for dissection through the interdural space without entering the neurovascular compartment of the cavernous sinus. Surgical series are needed to demonstrate any clinical advantages and disadvantages of this novel route.
... 29 Moreover, the safety of such kind of surgery has been confirmed also by the emerging experiences on transorbital endoscopic approach to orbital pathologies, where the orbit is much more manipulated given the periorbit opening and the intraorbital dissection. [30][31][32][33] and morphology of the skull base lesion in a given patient is within reach. 36 The role of transorbital endoscopic approaches in the context of complex skull base lesions is continuously being refined and the modern surgeons must stay abreast of all advances in their field in order to provide the best care for their patients. ...
Background:
Transorbital endoscopic surgery is one of the most recent fields of skull base surgery. This paper presents the emerging applications of transorbital endoscopic approaches to the skull base and their current results on the treatment of selected extradural and intradural lesions, based on a review of meta-analysis and recent clinical series.
Methods:
A PubMed, Cochrane and Ovid search for articles published from 2000 to 2015 about "endoscopic skull base surgery", "transorbital endoscopic approach", and "transorbital neuroendoscopic surgery " was performed. No anatomical or preclinical studies were included in the present review. Among the clinical case series available, only those describing transorbital approaches to the skull base have been considered, excluding from the analysis the studies addressing the orbit and orbital pathologies.
Results:
Although performed in extremely selected cases, there is a growing body of evidence suggesting that this technique may be effective for the treatment of cerebrospinal fluid leaks, for the drainage of epidural abscess or hematoma, and for the removal of several skull base tumors such as spheno-orbital meningioma. For the treatment of intradural pathologies there is only anecdotal evidence suggesting effectiveness and safety. Factors that may contribute to the enhanced efficacy compared to traditional external approaches were the acceptable complication rates, the reduced hospitalization time and limited morbidity for the patients, avoiding the need for large external craniotomies and brain retraction.
Conclusions:
Minimally invasive endoscopic skull base surgery has substantially evolved in the last decades through the collaboration of different teams around the world. The transorbital endoscopic approaches directed to the anterior and middle cranial base may represent safe and feasible techniques with great potential for new applications in the nearby future.
... In this scenario, transorbital endoscopic approaches (TEA), which provide several corridors through the orbit to reach lateral areas of the ventral skull base, are becoming increasingly utilized. [2][3][4][5][6][7][8][9][10][11][12] TEAs were first reported for treatment of orbital trauma [13] and subsequently extended to the management of orbital lesions. [9,14] More recently, Balakrishnan and Moe [2] classified orbit-related endoscopic surgery in orbital endoscopic, transorbital endoscopic, and transorbital neuroendoscopic approaches, in which the orbit was the primary target, the pathway towards the anterior and middle skull base, and the corridor to reach intracranial regions, respectively. ...
Background:
In recent years, transorbital endoscopic approaches (TEA) are increasing in popularity as they provide several corridors to reach lateral areas of the ventral skull base through the orbit. The aim of this study is to investigate the feasibility of the inferolateral transorbital endoscopic approach (ILTEA) by detailing the step-by-step dissection, anatomical landmarks, and target anatomical areas.
Methods:
Seven cadaveric specimens (14 sides) were dissected in the Laboratory of Endoscopic Anatomy of the University of Brescia. Step-by-step dissection of ILTEA was performed to identify the main anatomical landmarks and corridors. Skin incision, dural incision, and boundaries of craniectomy were measured. Neuronavigation was used to check landmarks, track boundaries of surgical volumes, and measure orbital dislocation.
Results:
The study on 14 ILTEAs defined one anatomical area (called "waterline door"), which guides to 4 corridors: Meckel's cave corridor, carotid foramen corridor, petrous corridor, and transdural middle fossa corridor. Crucial anatomical landmarks were identified and analyzed. Orbital dislocation was less than 10 mm.
Conclusions:
ILTEA provides the surgeon with a direct route to the region of the "waterline door", lateral areas of the ventral skull base, and middle cranial fossa. Moreover, it allows an optimal view of the intra- and extra-cranial portions of the maxillary and mandibular nerves. Further anatomical and clinical studies are needed to validate ILTEA in surgical practice.
The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.
BACKGROUND: Cavernous venous malformation of the orbit, formerly known as cavernous hemangioma of the orbit, refers to vascular malformations with slow blood flow, and is a frequent lesion of the orbit in adults. The spread of cavernous venous malformation of the orbit into the cranial cavity is extremely rare. AIM: The aim of this study is a comparative analysis of ophthalmological manifestations of orbitocranial and orbital cavernous venous malformation. MATERIALS AND METHODS: The analysis was performed on 50 patients operated in N.N. Burdenko National Scientific and Practical Center for Neurosurgery from 2004 till 2023. Two groups of patients with сavernous venous malformation of the orbit were identified: group 1 — with malformation spreading into the cranial cavity, group 2 —with malformation localized in the orbit only. RESULTS: In 29 patients, cavernous venous malformation of the orbit spread into the cranial cavity through superior orbital fissure, inferior orbital fissure, optic canal and/or through combinations thereof; in 21 patients, the malformation was located in the orbit only. Females prevailed in both groups; the average age was 44 years. The first group included patients with the following features: visual impairments were more frequent and more prominent, oculomotor disorders caused mainly by the involvement of oculomotor and abducens nerves; optic nerve atrophy, slight proptosis. The second group was identified by more prominent proptosis, more mild visual impairments, oculomotor disorders caused by the presence of the malformation in the orbit, at the eye fundus, optic nerve head edema prevailed. CONCLUSIONS: Ophthalmic symptoms due to topographic and anatomical variants of a cavernous malformation.
The etiology of trigeminal neuralgia is basically caused by neurovascular conflict. However, there are cases where trigeminal neuralgia occurs due to other causes when encountering patients in clinical practice. This article summarizes the cases with other pathology among these cases.Among the things that can cause trigeminal neuralgia, the most easily encountered is the tumor located in a cerebello-pontine angle or Meckel’s cave. Among them, meningioma and schwannoma are the most common causes of secondary trigeminal neuralgia. In this case, treatment can be carried out in various ways. Some surgeons give priority to surgical resection of tumors, but other surgeons may treat it through stereotactic radiosurgery.If the tumor is removed through microscopic surgery and the trigeminal nerve is decompressed, the success rate is 86% and above. However, when applying stereotactic radiosurgery, the final pain relief rate is only 36%, with 28.3% of recurrence rate.There are also clear advantages of stereotactic radiosurgery. However, when trigeminal neuralgia is the main symptom, surgical resection is considered to be a more efficient and safe treatment.
Objective:
Endoscopic transorbital approach represents a minimally invasive route which could be particularly appropriated for the management of spheno-orbital meningiomas. We provide a systematic review of the literature, together with four illustrative cases, about the management of spheno-orbital meningiomas by means of the minimally invasive endoscopic transorbital route, underlining clinical scenarios in which such strategy could be best indicated.
Methods:
A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Available data including patients' demographics, tumors' features, surgical and postoperative outcomes were collected.
Results:
Data of 58 patients, both from 9 selected records and from authors' surgical series, were collected. Rates of subtotal, near-total and gross-total resection were 44,8%, 10,3% and 32,7%, respectively. Rates of symptoms improvement after surgery were 100% for proptosis, 93% for visual impairment and 87% for ophthalmoplegia. The most common post-operative complications were transient ophthalmoplegia and V2 hypoesthesia. Cerebro-spinal fluid leak was reported in 2 patients.
Conclusions:
Our findings support the applicability of the transorbital approach for the management of spheno-orbital meningiomas, particularly in at least three clinical scenarios: 1) when predominant hyperostotic bone is present; 2) when a globular tumor, not showing excessive medial or inferior infiltration, is addressed; 3) as part of a multi-staged treatment for diffuse lesions.
Transorbital approaches are genuinely versatile surgical routes which show interesting potentials in skull base surgery. Given their “new” trajectory, they can be a very useful adjunct to traditional routes, even being a valid alternative to them in some cases, and add valuable opportunities in selected patients. Indications are constantly expanding, and currently include selected intraorbital, skull base and even intra-axial lesions, both benign and malignant. Given their relatively recent development and thus unfamiliarity among the skull base community, achieving adequate proficiency needs not only a personalized training and knowledge but also, above all, an adequate case volume and a dedicated setting. Current, but mostly future, applications should be selected by genetic, omics and biological features and applied in the context of a truly multidisciplinary environment.
Objective:
To explore the feasibility of navigation-guided sinus endoscopy to remove the cavernous vascular malformation of the orbital apex through the sphenoid approach.
Methods:
A retrospective series of non-control cases were collected. From May 2012 to December 2019, patients with imaging findings of cavernous venous malformation in the orbital apex were collected at the Eye Hospital Affiliated to Nanchang University. All patients underwent navigation guided sinusoscopy through the sphenoid approach to remove the cavernous venous malformation of the orbital apex. Analyze the changes of visual function and postoperative complications before and after operation.
Results:
Twelve patients were collected, including 3 males and 9 females aged between 32 and 59. In 3 patients without visual impairment, the postoperative visual function was still normal. The remaining 9 patients all had visual impairment. Among them, 3 patients had fully recovered normal visual function after operation, 2 patients had improved visual function compared with preoperative, and 4 patients had no change in postoperative visual acuity. There were no complications in 3 of the 12 patients, and 9 patients had transient limited intraocular rotation with mild limitation of diplopia after operation, and all returned to normal within 1 month after surgery.
Conclusion:
Navigation-guided sinus endoscopy through the sphenoid approach to remove the cavernous venous malformation of the orbital apex is an effective and feasible surgical method.
Background:
Transorbital neuroendoscopic surgery (TONES) offers a new level of minimally invasive, minimally disfiguring skull base surgery with maximal surgical visualization.
Methods:
This review systematically assesses the body of published anatomical (cadaveric) and clinical evidence for the approach. PubMed, Cochrane Library, Ovid MEDLINE, and EMBASE were systematically searched for publications where the TONES surgical technique was used in an anatomical, clinical, or combined study. The outcomes of interest included identification of the pathologies, operative outcomes, and complication rates.
Results:
Twenty-three papers were selected for this systematic review: 10 were purely anatomical, 10 were clinical, and 3 had both clinical and cadaveric components. The papers reported 69 patients undergoing transorbital or combined transorbital and transnasal intervention. A total of 30 cases of cerebrospinal fluid leak were documented; of these, 28 (93%) had successful resolution, 2 (7%) had recurrence, and 5 (15%) experienced complications. A total of 31 tumors were biopsied (n=1), resected (n=22), or debulked (n=8). Meningiomas were the most common lesion managed via TONES, with 5 of 7 patients with meningioma who reported preoperative neurological deficits experiencing an improvement in extraocular movement impairment, visual acuity, proptosis, and ptosis. Transient postoperative clinical sequelae, including diplopia and ptosis, were increasingly associated with the superior lid crease incision and the sole transorbital approach.
Conclusions:
TONES is a significant development in transorbital skull base surgery. However, comprehensive, robust, comparative analyses and increasing use and generalizability of this technique in skull base surgery are awaited.
Endoscopic surgery of the orbit, periorbital region, and adjacent areas of the anterior and middle cranial fossae and brain has gained significant popularity over the last decade. These procedures are now being used at multiple institutions internationally with a success and safety record that has been demonstrated to be at par with or better than other techniques. The approaches provide minimally disruptive, scarless access to regions that previously required extensive open operations with significant retraction of critical neurovascular structures leading to prolonged morbidity and hospitalization.
This paper will describe the basic techniques of these approaches, how they can be used alone or in multiportal (para- and contraportal) technique and guide the reader to resources for further learning.
The orbital apex is a small, cone-shaped region located between the posterior ethmoidal foramen anteriorly, and the openings of the optic canal and superior orbital fissure posteriorly. It contains many critical neurovascular structures, such as the optic, oculomotor, abducens, and ophthalmic branch of the trigeminal nerve, along with the cavernous sinus, carotid artery, and periarterial sympathetic plexus. At this level extraocular muscles attach to the annulus of Zinn, a fibrous ring that surrounds the optic canal and the inferior part of the superior orbital fissure. Lesions in the orbital apex are rare, and they usually produce symptoms such as visual acuity reduction, extraocular muscle impairment with diplopia, pain, and exophthalmos. The differential diagnosis is broad and includes inflammatory, infectious, traumatic, vascular, and neoplastic causes. External surgical approaches to the orbit are well established. External orbitotomies can be performed with or without osteotomy and, in cases of more extensive tumors, the orbitozygomatic craniotomy offers a wide exposure of the orbital contents. However, medial and inferior orbital lesions are the most difficult to reach and are usually addressed via a transcutaneous or transconjunctival medial orbitotomy. These approaches are demanding for posterior tumors, because the cone-shaped surgical field is narrow and damage to neural, muscular, or vascular structures of the orbit can have serious consequences. For intraconal lesions, a temporary section of the medial rectus muscle and retraction of the globe can be required. Reports of endoscopic transnasal approaches to the orbit have been frequently published during the past several years, so endoscopic orbital surgery can now be considered as an alternative option to traditional external approaches in the management of selected orbital lesions.
Objective:
Sphenoid wing meningiomas (SWMs) can be treated with complete surgical resection and recent endoscopic transorbital approach (ETOA) offers one of minimally invasive alternatives. The authors compare the surgical outcome of ETOA and extended mini-pterional approach (eMPTA) for SWMs with osseous involvement.
Methods:
From October 2015 to May 2019, a total of 24 patients underwent surgery for SWMs with osseous involvement. Among them, tumor resection was performed by ETOA for 11 patients (45.8%) and eMPTA for 13 patients (54.2%). The tumor characteristics, surgical outcome and morbidity, and approach-related aesthetic outcome were analyzed and compared retrospectively between ETOA and eMPTA based on SWM classification.
Results:
The location of SWMs was mostly middle sphenoid ridge (group III) (45.8%), followed by greater sphenoid wing (group IV) (29.2%). Simpson resection grades I/II were achieved in 9 of 11 patients (81.8%) with ETOA and 11 of 13 patients (84.6%) with eMPTA. There were no differences in tumor characteristics between the two approaches. Surgery time, surgical bleeding, and hospital length of stay were significantly shorter with ETOA. Three patients had transient surgical morbidities such as diplopia (n=1), ptosis (n=1), and cerebrospinal fluid leak (n=1) after ETOA. No differences could be seen in surgical morbidities between ETOA and eMPTA.
Conclusions:
ETOA can provide direct access to the sphenoid bone and resectability with a more rapid and minimally invasive exposure than eMPTA. Maximal subtotal resection with extensive sphenoid bone decompression for tumors with CS infiltration is the key to a good clinical outcome, regardless of the surgical approach.
In the study and practice of neurosurgery at the "Federico II" University of Naples, a central role has always been reserved for anatomy. Based on worldwide cooperation, the meaning of anatomical research has evolved from methodological investigation to an educational and communication tool. The contribution of our school to the anatomical data on the sellar region has been chronologically reviewed in the present report. The path that brought us to focus on the endoscopic endonasal anatomy has been presented, together with the evolution of anatomical investigation. The confidence achieved with decades of cadaveric laboratory studies has changed the profile of our anatomical investigations. The quantification and comparison became essential in these studies owing to their effect on surgical application and advanced imaging techniques entered the field of anatomical dissection. Anatomy at our school is an evolving science. Our efforts in anatomical scientific publications and organization of participatory courses have made us a center of reference for endoscopic endonasal surgery and have allowed us to share our knowledge with other specialists in this field.
Objective:
Trigeminal schwannomas are rare neoplasms with an incidence of less than 1% that require a comprehensive surgical strategy. These tumors can occur anywhere along the path of the trigeminal nerve, capable of extending intradurally into the middle and posterior fossae, and extracranially into the orbital, pterygopalatine, and infratemporal fossa. Recent advancements in endoscopic surgery have suggested a more minimally invasive and direct route for tumors in and around Meckel's cave, including the endoscopic endonasal approach (EEA) and endoscopic transorbital superior eyelid approach (ETOA). The authors assess the feasibility and outcomes of EEA and ETOA for trigeminal schwannomas.
Methods:
A retrospective multicenter analysis was performed on 25 patients who underwent endoscopic surgical treatment for trigeminal schwannomas between September 2011 and February 2019. Thirteen patients (52%) underwent EEA and 12 (48%) had ETOA, one of whom underwent a combined approach with retrosigmoid craniotomy. The extent of resection, clinical outcome, and surgical morbidity were analyzed to evaluate the feasibility and selection of surgical approach between EEA and ETOA based on predominant location of trigeminal schwannomas.
Results:
According to predominant tumor location, 9 patients (36%) had middle fossa tumors (Samii type A), 8 patients (32%) had dumbbell-shaped tumors located in the middle and posterior cranial fossae (Samii type C), and another 8 patients (32%) had extracranial tumors (Samii type D). Gross-total resection (GTR, n = 12) and near-total resection (NTR, n = 7) were achieved in 19 patients (76%). The GTR/NTR rates were 81.8% for ETOA and 69.2% for EEA. The GTR/NTR rates of ETOA and EEA according to the classifications were 100% and 50% for tumors confined to the middle cranial fossa, 75% and 33% for dumbbell-shaped tumors located in the middle and posterior cranial fossae, and 50% and 100% for extracranial tumors. There were no postoperative CSF leaks. The most common preoperative symptom was trigeminal sensory dysfunction, which improved in 15 of 21 patients (71.4%). Three patients experienced new postoperative complications such as vasospasm (n = 1), wound infection (n = 1), and medial gaze palsy (n = 1).
Conclusions:
ETOA provides adequate access and resectability for trigeminal schwannomas limited in the middle fossa or dumbbell-shaped tumors located in the middle and posterior fossae, as does EEA for extracranial tumors. Tumors predominantly involving the posterior fossa still remain a challenge in endoscopic surgery.
OBJECTIVE
Tumors involving Meckel’s cave remain extremely challenging because of the surrounding complex neurovascular structures and deep-seated location. The authors investigated a new minimal-access technique using the endoscopic transorbital approach (eTOA) through the superior eyelid crease to Meckel’s cave and middle cranial fossa lesions and reviewed the most useful surgical procedures and pitfalls of this approach.
METHODS
Between September 2016 and January 2018, the authors performed eTOA in 9 patients with tumors involving Meckel’s cave and the middle cranial fossa. The lesions included trigeminal schwannoma in 4 patients, meningioma in 2 patients, metastatic brain tumor in 1 patient, chondrosarcoma in 1 patient, and dermoid cyst in 1 patient. In 7 of the 9 patients, eTOA alone was performed, while the other 2 patients underwent a combined eTOA and endoscopic endonasal approach or retrosigmoid craniotomy. Data including details of surgical techniques and clinical outcomes were recorded.
RESULTS
Gross-total resection was performed in 7 of the 9 patients (77.8%). Four patients underwent extended eTOA (with lateral orbital rim osteotomy). Drilling of the trapezoid sphenoid floor, a middle fossa “peeling” technique, and full visualization of Meckel’s cave were applied to approach the lesions. Tumors were exposed and removed extradurally in 3 patients and intradurally in 6 patients. There was no postoperative CSF leak.
CONCLUSIONS
The eTOA affords a direct route to access Meckel’s cave and middle cranial fossa lesions. With experience, this novel approach can be successfully applied to selected skull base lesions. To achieve successful removal of the tumor, emphasis should be placed on the importance of adequately removing the greater sphenoid wing and vertical crest. However, because of limited working space eTOA may not be an ideal approach for posterior fossa lesions.
Background
Cryoprobe devices are used by ophthalmic and orbital surgeons for extraction of fluid-filled intraorbital lesions. No series has described cryodissection via an exclusively transnasal approach. We describe 2 cases of purely endoscopic transnasal removal of intraconal orbital hemangiomas with the aid of a dedicated cryoprobe.
Methods
All transnasal endoscopic intraorbital procedures were collected and analyzed. In cases in which intraorbital dissection was performed with the use of an Optikon Cryo-line probe, clinical features, histology, size and location of the lesion, early and late complications, surgical procedure time, and hospital length of stay were analyzed. Patient follow-up included endoscopic endonasal evaluations performed at 2, 4, and 8 weeks after surgery and ophthalmologic and orthoptic evaluations performed 2 days and 2 months after surgery.
Results
Two transnasal intraorbital endoscopic procedures with the aid of the dedicated Cryo-line probe were collected. Lesions were located in the intraconal space, medial to the optic nerve. In both patients, the histologic evaluation was compatible with cavernous hemangioma, and complete resection was obtained. Mean hospital stay was 5.5 days. Postoperative ophthalmologic and orthoptic evaluations performed 2 months postoperatively revealed complete resolution of preoperative symptoms.
Conclusions
Cryoprobes represent an adjunctive tool in the orbital surgeon's armamentarium useful in the extraction of fluid-filled intraorbital lesions. This preliminary experience suggests that their use can ease the removal of intraconal hemangiomas with an exclusively transnasal approach. The analysis of further cases is necessary to confirm safety and efficacy.
Objective The aim of this anatomic study is to describe a fully endoscopic lateral orbitotomy extradural approach to the cavernous sinus, posterior, and infratemporal fossae.
Material and Methods Three prefixed latex-injected head specimens (six orbital exposures) were used in the study. Before and after dissection, a computed tomography scan was performed on each cadaver head and a neuronavigation system was used to guide the approach. The extent of bone removal and the area of exposure of the targeted corridor were evaluated with the aid of OsiriX software (Pixmeo, Bernex, Switzerland).
Results The lateral orbital approach offers four main endoscopic extradural routes: the anteromedial, posteromedial, posterior, and inferior. The anteromedial route allows a direct route to the optic canal by removal of the anterior clinoid process, whereas the posteromedial route allows for exposure of the lateral wall of the cavernous sinus. The posterior route is targeted to Meckel's cave and provides access to the posterior cranial fossa by exposure and drilling of the petrous apex, whereas the inferior route gives access to the pterygopalatine and infratemporal fossae by drilling the floor of the middle cranial fossa and the bone between the second and third branches of the trigeminal nerve.
Conclusion The lateral orbitotomy endoscopic approach provides direct access to the cavernous sinus, posterior, and infratemporal fossae. Advantages of the approach include a favorable angle of attack, minimal brain retraction, and the possibility of dissection within the two dural layers of the cavernous sinus without entering its neurovascular compartment.
Purpose: To present a new surgical technique for excision of orbital cavernous hemangiomas (CHs).
Methods: This retrospective case series study included patients with orbital CH who were operated from 2001 to 2016 at our referral center. Epidemiologic data, symptoms, signs, and images were reviewed from patients’ files with at least one year of follow-up. Surgical results and complications were documented. We used the “index finger dissection” technique without grasping the tumor for release of adhesions and its removal.
Results: We included 60 patients with orbital CH consisting of 36 (60%) female and 24 (40%) male patients with mean age of 40 ± 12.1 (range 9–66) years.
The main complaint was proptosis with average size of 5.3 ± 2 millimeters. The surgical approach was lateral orbitotomy in 49 (81.7%) patients, medial transcutaneous in seven (11.7%) patients, inferior transconjunctival in three (5%) patients, and simultaneous lateral and medial orbitotomy in one (1.6%) patient. All tumors were removed intact; complications included ptosis in one subject, lower lid retraction in one case, and diplopia in two patients, all of which improved before 2 months. No optic nerve damage occurred.
Conclusion: The “index finger dissection” technique without grasping the tumor for excision of orbital CH, via any external approach to the tumor, is a safe technique with minimal complications.
Sphenoorbital meningiomas (SOMs) are slow-growing tumors that originate from the sphenoidal wing and are associated with visual deterioration, extrinsic ocular movement disorders, and proptosis caused by hyperostosis of the lateral wall of the orbit. In some cases, the intracranial component is quite small or “en plaque,” and the majority of the symptoms arise from adjacent hyperostosis. Craniotomy has traditionally been the standard of care, but new minimally invasive multiportal endoscopic approaches offer an alternative. In the current study, the authors to present their experience with the transorbital endoscopic eyelid approach for the treatment of 2 patients with SOMs and sphenoid wing hyperostosis.
Clinical and radiological data for patients with SOMs who underwent a transorbital endoscopic eyelid approach were retrospectively reviewed. Surgical technique and clinical and radiographic outcomes were analyzed.
The authors report the cases of 2 patients with SOMs and proptosis due to sphenoid wing hyperostosis. One patient underwent prior craniotomy to debulk the intracranial portion of the tumor, and the other had a minimal intracranial component. Both patients were discharged 2 days after surgery. MR images and CT scans demonstrated a large debulking of the hyperostotic bone. Postoperative measurement of the proptosis with the aid of an exophthalmometer demonstrated significant reduction of the proptosis in one of the cases. Persistence of intraconal tumor in the orbital apex limited the efficacy of the procedure in the other case. A review of the literature revealed 1 publication with 3 reports of the transorbital eyelid approach for SOMs. No measure of relief of proptosis after this surgery had been previously reported.
The transorbital endoscopic approach, combined with endonasal decompression of the medial orbit, may be a useful minimally invasive alternative to craniotomy in a subset of SOMs with a predominantly hyperostotic orbital wall and minimal intracranial bulky or merely en plaque disease. In these cases, relief of proptosis and optic nerve compression are the primary goals of surgery, rather than gross-total resection, which may have high morbidity or be unachievable. In cases with significant residual intraconal tumor, orbital bone removal alone may not be sufficient to reduce proptosis.
Background:
The availability of minimal access instrumentation and endoscopic visualization has revolutionized the field of minimally invasive skull base surgery. The transorbital endoscopic approach using an eyelid incision has been proposed as a new minimally invasive technique for the treatment of skull base pathology, mostly extradural tumors. Our study aims to evaluate the anatomical aspects and potential role of the transorbital endoscopic approach for exposure of the sylvian fissure, middle cerebral artery and crural cistern.
Methods:
An anatomical dissection was performed in four freshly injected cadaver heads (8 orbits) using 0- and 30-degree endoscopes. First, an endoscopic endonasal medial orbital decompression was done to facilitate medial retraction of the orbit. An endoscopic transorbital approach through an eyelid incision, with drilling of the posterior wall of the orbit and lesser sphenoidal wing, was then performed to expose the sylvian fissure and crural cisterns. A stepwise anatomical description of the approach and visualized anatomy is detailed.
Results:
A superior eyelid incision followed by orbital retraction provided a surgical window of approximately 1.2 cm (range 1.0-1.5 cm) for endoscopic transorbital dissection. The superior (SOF) and inferior (IOF) orbital fissures represent the medial limits of the approach and are identified in the initial part of the procedure. Drilling of the orbital roof (lateral and superior to the SOF), greater sphenoidal wing (lateral to the SOF and IOF) and lesser sphenoidal wing exposed the anterior and middle fossa dura. A square-shaped dural opening provided visualization of the posterior orbital gyri, sylvian fissure and temporal pole. Intradural dissection allowed exposure of the sphenoidal portion of the sylvian fissure, M1, MCA bifurcation and M2 branches and lenticulostriate perforators. Dissection of the medial aspect of the sylvian and carotid cisterns with a 30-degree endoscope allowed exposure of the mesial temporal lobe and crural cistern.
Conclusions:
The transorbital endoscopic approach allows successful exposure of the sphenoidal portion of the sylvian fissure and M1 and M2 segments of the middle cerebral artery. Angled endoscopes may provide visualization of the mesial temporal lobe and crural cistern. Although our anatomical study demonstrates the feasibility of intradural dissection and closure via an endoscopic transorbital approach, further studies are necessary to evaluate its role in the clinical scenario.
Background and aims:
Various surgical routes have been used to decompress the intracanalicular optic nerve. Historically, a transcranial corridor was used, but more recently ventral approaches (endonasal and/or transorbital) have been proposed, individually or in combination. The present study aims to detail and quantify the amount of bony optic canal removal one may achieve via transcranial, transorbital and endonasal pathways. Additionally, the surgical freedom of each approach was analyzed.
Methods:
In 10 cadaveric specimens (20 canals), optic canals were decompressed via pterional, endoscopic endonasal, and endoscopic superior eyelid transorbital corridors. The surgical freedom and circumferential optic canal decompression afforded by each approach was quantitatively analyzed. Statistical comparison was carried using a non-paired Student t-test.
Results:
An open pterional transcranial approach allowed the greatest area of surgical freedom (transcranial: 10.9 ± 3.4 cm2; transorbital 3.7 ± 0.5 cm2; endonasal homolateral 1.1 ± 0.6 cm2 and endonasal contralateral 1.1 ± 0.5 cm2) with widest optic canal decompression when compared with the other two ventral routes (transcranial: 245.2°; transorbital: 177.9°; endonasal: 144.6°). These differences reached statistical significance for the transcranial approach.
Conclusions:
This anatomical contribution provides a comprehensive evaluation of surgical access to the optic canal via three distinct, but complementary, approaches: transcranial, transorbital and endonasal. Our results show that, as expected, a transcranial approach achieved the widest degree of circumferential optic canal decompression and the greatest surgical freedom for manipulation of surgical instruments. Further surgical experience is necessary to determine the proper surgical indication for the transorbital approach to this pathology.
The superior orbital fissure is a critical three-dimensional space connecting the middle cranial fossa and the orbit. From an endoscopic viewpoint, only the medial aspect has a clinical significance. It presents a critical relationship with the lateral sellar compartment, the pterygopalatine fossa and the middle cranial fossa. The connective tissue layers and neural and vascular structures of this region are described. The role of Muller's muscle is confirmed, and the utility of the maxillary and optic strut is outlined. Muller's muscle extends for the whole length of the inferior orbital fissure, passes over the maxillary strut and enters the superior orbital fissure, representing a critical surgical landmark. Dividing the tendon between the medial and inferior rectus muscle allows the identification of the main trunk of the oculomotor nerve, and a little laterally, it is usually possible to visualize the first part of the ophthalmic artery. Based on a better knowledge of anatomy, we trust that this area could be readily addressed in clinical situations requiring an extended approach in proximity of the orbital apex.
The objective of the study is to present our multicentric experience on intraorbital lesions managed by means of an endonasal endoscopic approach. The study design used was multi-institutional retrospective review. We collected data on 16 intraorbital medially-located lesions, all managed by means of an endonasal route, treated in four different skull base centers. We retrospectively reviewed the technical details, complications, histology, and general outcome. The endoscopic endonasal approach was effective in removing completely intraorbital extra-intraconal tumors in 8 cases, in performing biopsies for histological diagnosis in 6 intraorbital intraconal tumors, and in draining 1 extraconal abscess. No major complications were observed; in particular, there was no optic nerve damage. Minor, temporary complications (diplopia) were seen in 3 cases; only 2 patients experienced a permanent diplopia related to medial rectus muscle impairment, in 1 case associated with enophthalmos. Our preliminary multi-centric clinical experience suggests that medially located intraorbital lesions, and in particular the infero-medial ones, can be successfully and safely managed by such an approach. The well-known advantages of the endoscopic techniques, namely the lack of external scars, less bleeding, shorter hospital stay, and fewer complications, are confirmed.
Graves' ophthalmopathy is an inflammatory disease of the orbital tissues that especially affects extraocular muscles and fat. Orbital decompression is performed to reverse compressive neuropathy and reduce proptosis. The most widely used technique is the inferomedial orbital decompression, which may provide an insufficient decompression in patients with serious proptosis. A balanced decompression of the medial and lateral orbital walls provides >5 mm of proptosis reduction with a low occurrence of postoperative diplopia.
Cavernous haemangiomas are well circumscribed vascular masses which commonly occur in middle-aged women. The majority occur within the muscle cone lateral to the optic nerve and produce a slowly progressive and painless proptosis. Predilection for sites lateral to the optic nerve may be related to origin from arterial rather than venous elements. Complete excision is usually possible and surgical morbidity is low. A series of 85 consecutive cases is reported.
Intraconal tumors of the orbit are rare entities and surgical treatment is challenging. Endoscopic transnasal approaches to the orbit offer a new perspective for surgery, although only few reports exist in literature. This study displays the Graz experience with endoscopic approaches to intraorbital tumors between 2006 and 2010 introducing a novel endoscopic technique for temporary medialization of the medial rectus muscle facilitating access to the orbital cone.
A retrospective analysis of patients' charts was performed.
For approaches to intraconal lesions a special endoscopic temporary medialization technique of the medial rectus muscle through applying transseptal sutures was developed. Six patients (four male and two female patients) have been included in this study presenting with intraconal/intraorbital tumors. Three patients underwent endoscopic surgery for two hemangiomas and one Schwannoma, respectively, and three patients were successfully biopsied endoscopically revealing one malignant melanoma, one malignant lymphoma, and one optic glioma each. Both hemangiomas were completely resected without any deterioration of vision. The Schwannoma was partially resected with postoperative imaging showing no tumor progression within 3 months. No intraoperative complications occurred. Five cases were performed with computer assisted surgery using CT/MR fusion navigation.
Although technically challenging, the endoscopic approach to the orbit, even for intraconal lesions with medialization of the medial rectus muscle, can be safe and promising for well-selected cases. Good postoperative results and sufficient material acquisition for proper histological examination can be obtained. Advantages are good visualization of the surgical field and avoidance of external scars. Limitations to endoscopic techniques are tumors in the lateral superior and lateral inferior quadrant of the orbit.
Extended endoscopic endonasal approaches are increasingly applied to treat a variety of orbital pathologies. We performed a cadaveric study, comparing the endonasal approach with a transcranial approach to the orbital apex, using a two-dimensional (2D) and novel three-dimensional (3D) endoscope.
Dissection was performed on two fresh cadaver heads using a novel 3D endoscope for the endonasal approach to the orbit and orbital apex. On the same heads, a fronto-orbito-zygomatic (FOZ) approach was performed to expose the orbital apex region. Anatomical boundaries and limitations of each exposure were noted. 2D and 3D images of the approaches and anatomical dissections were captured and recorded.
The endonasal endoscopic approach achieved direct exposure to the inferior and medial aspects of the orbit. The FOZ approach, on the other hand, provided excellent access to the superior and lateral aspects of the orbit. Appreciation of the spatial relationships of the intracranial skull base anatomy was significantly improved using the 3D endoscope compared with the 2D endoscope.
The endoscopic endonasal approach achieves direct exposure to the inferomedial aspect of the orbit and orbital apex, which is not exposed using the transcranial approach, hence the two approaches are complementary. 3D endoscopes augment the spatial orientation of extracranial and intracranial anatomical structures. This may improve patient's safety and hasten the learning curve for endoscopic approaches to the midline skull base.
To consider the pathogenesis and growth of cavernous hemangioma, particularly within the crowded orbital apex, in decisions regarding surgical indications, timing, and technique.
A perspective based on analysis of the microanatomic relationships and growth potential of apical cavernous hemangiomas, with representative case studies illustrating management recommendations.
Analysis of microscopic findings in typical and vision-loss cases; review of tumor growth patterns as reported in observational and interventional studies; consideration of surgical approaches and reported functional outcomes.
An ongoing, local hemodynamic imbalance may drive the proliferation of a cavernous hemangioma. Extension into neighboring tissue induces a fibrous capsule, which is continually reconstituted as the lesion expands, and which may incorporate visually critical structures in the confines of the apex. The extent of this microanatomic intimacy is not detectable preoperatively. The tumor's remaining growth potential at the time of diagnosis or following incomplete resection is not predictable.
Patients without significant vision deficits should be observed for progression. Those with significant deficits or signs of progression should be offered timely surgery, with recognition of the risks. The surgical approach should be individualized based on macroanatomic relationships. The decision to intervene should not be a commitment to complete resection at any cost; intraoperative recognition of "inoperable" attachments may dictate modifications in order to preserve vision.
External approaches to the orbit are well established, including the lateral, medial, and inferior orbitotomy. Orbitozygomatic craniotomy can be used for tumors that extend both intracranially and into the orbit and is used for exposure of the optic nerve and canal.(1) Since the 1980s, endoscopic measures have been used to enhance visualization in standard external approaches.(2) Endoscopic endonasal orbital and optic nerve decompressions have become accepted treatments for thyroid eye disease and traumatic optic neuropathy that is unresponsive to steroids. A few case reports of endoscopic decompression, biopsy, and resection of tumors that involve the orbit also have been reported.(3-5) The expanded endonasal approach (EEA) has been extended to resection of all types of skull base tumors, including posterior, middle, and anterior fossa masses. In this report, we describe the anatomic principles, indications, technical nuances, and limitations of the medial-inferior intraconal EEA to intraorbital tumor surgery, illustrated through a case series of six patients. This approach is ideally suited to benign soft-tissue masses (hemangioma/lymphangioma) in the medial-inferior quadrant of the orbit that do not extend superolaterally. The use of this technique would avoid the technical difficulties in approaching such masses and limit the dissection to the areas bordering the endonasal corridor.
Transorbital neuroendoscopic surgery (TONES) pathways attempt to address some of the technical challenges of accessing laterally placed anterior skull base lesions or paramedian lesions that cross neurovascular structures. TONES approaches allow simultaneous coplanar visualization and working space above and below the skull base.
To present an anatomic study, a description of the surgical techniques, and an analysis of the safety and efficacy of 20 consecutive procedures using TONES for a variety of pathological conditions.
Sixteen patients underwent 20 TONES procedures for anterior skull base pathology, including repair of cerebrospinal leak, optic nerve decompression, repair of cranial base fractures, and removal of 3 skull base tumors. Ten patients were male, and 6 were female. The mean age at presentation was 44 years. Follow-up was 6 to 18 months with a mean of 9 months.
There were no significant complications or treatment failures in any of the 20 procedures. A variety of pathological conditions were treated, including cerebrospinal fluid leaks, fractures, mass lesions, and tumors. The TONES approach provided up to 4 separate access ports with ample exposure for manipulation and correction of the pathology.
This anatomic and prospective outcome study demonstrates that TONES provides safe and effective coplanar endoscopic access to the anterior and middle cranial base. These novel TONES approaches may be added to the wide range of published minimally invasive armamentarium when approaching challenging skull base pathology.
The clinical and pathological data of 66 patients with orbital cavernous hemangioma are presented. This tumor occurs in females more frequently than in males, and has its peak incidence in early middle age. Visual disability results from a high degree of relative hyperopia or from optic-nerve compression. Postural or temporal variation is proptosis is not characteristic. Multiple cavernous hemangiomas are rare, but may occur simultaneously or separated by long intervals. In this series, incompletely excised lesions did not cause recurrent proptosis. Relative hyperopia may persist, in spite of complete removal of the tumor. Improved preoperative localization with modern techniques appears to be reducing the morbidity associated with surgical excision of the lesion. A local hemodynamic disturbance may initiate proliferation of vascular channels that undergo progressive ectasia. Growth of the lesion may occur intrinsically by the budding-off of capillary channels from cavernous spaces into the interstitium. Clinical and pathological findings fail to demonstrate any relationship between this lesion and capillary hemangioma of childhood.
Cavernous haemangiomas are well circumscribed vascular masses which commonly occur in middle-aged women. The majority occur within the muscle cone lateral to the optic nerve and produce a slowly progressive and painless proptosis. Predilection for sites lateral to the optic nerve may be related to origin from arterial rather than venous elements. Complete excision is usually possible and surgical morbidity is low. A series of 85 consecutive cases is reported.
The article by Alfred and Char1 describing 19 operated cavernous hemangiomas and 6 unoperated cases, contains some inaccuracies and omits some relevant information in its discussion. Whilst cavernous hemangioma is probably the commonest intraconal primary orbital neoplasm, as quoted by these authors and others, cavernous hemangiomas regularly occur outside the intraconal space2, and in one of the largest orbital centres, primary orbital venous anomaliesflymphangioma, idiopathic orbital inflammation (pseudotumour) and lymphoid tumours are seen more commonly2.
The selection of the surgical approach to the orbit depends on the indication for surgery and the location, size, and extent of the lesion. For the anterior half of the orbit, anterior orbitotomy provides adequate exposure. For the posterior half, more extensive procedures with osteotomy are necessary. This article details the external approaches to the orbit. The traditional approaches for orbital decompression for Grave's ophthalmopathy are also described.
Endoscopic surgery inside and around the orbit
- I Dallan
- P Castelnuovo
- S Sellari-Franceschini
Dallan I, Castelnuovo P, Sellari-Franceschini S (2014) Endoscopic surgery inside and around the orbit. Silver Book, Karl
Storz, Tuttlingen, Germany (in press)