Objective: Cranioorbital tumors are complex lesions that involve the deep orbit, floor of the frontal bone, and lesser and greater wing of the sphenoid bone. The purpose of this study was to describe the clinical and ophthalmological outcomes with an endoscopic transorbital approach (TOA) in the management of cranioorbital tumors involving the deep orbit and intracranial compartment.

Methods: The authors performed endoscopic TOAs via the superior eyelid crease incision in 18 patients (16 TOA alone and 2 TOA combined with a simultaneous endonasal endoscopic resection) with cranioorbital tumors from September 2016 to November 2017. There were 12 patients with sphenoorbital meningiomas. Other lesions included osteosarcoma, plasmacytoma, sebaceous gland carcinoma, intraconal schwannoma, cystic teratoma, and fibrous dysplasia. Ten patients had primary lesions and 8 patients had recurrent tumors. Thirteen patients had intradural lesions, while 5 had only extradural lesions.

Results: Of 18 patients, 7 patients underwent gross-total resection of the tumor and 7 patients underwent planned near-total resection of the tumor, leaving the cavernous sinus lesion. Subtotal resection was performed in 4 patients with recurrent tumors. There was no postoperative CSF leak requiring reconstruction surgery. Fourteen of 18 patients (77.8%) had preoperative proptosis on the ipsilateral side, and all 14 patients had improvement in exophthalmos; the mean proptosis reduced from 5.7 ± 2.7 mm to 1.5 ± 1.4 mm. However, some residual proptosis was evident in 9 of the 14 (64%). Ten of 18 patients (55.6%) had preoperative optic neuropathy, and 6 of them (60.0%) had improvement; the median best-corrected visual acuity improved from 20/100 to 20/40. Thirteen of 18 patients showed mild ptosis at an immediate postoperative examination, all of whom had a spontaneous and complete recovery of their ptosis during the follow-up period. Three of 7 patients showed improvement in extraocular motility after surgery.

Conclusions: Endoscopic TOA can be considered as an option in the management of cranioorbital tumors involving complex anatomical areas, with acceptable sequelae and morbidity.

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: Feasibility and safety of spheno-orbital meningioma resection by means of endoscopic-assisted transorbital route.

Objective: To evaluate the feasibility and outcomes of the transorbital endoscopic management of selected spheno-orbital meningiomas. As secondary aims, symptom improvement and tumor volume removed were evaluated.

Methods: Retrospective chart evaluation of patients with spheno-orbital meningiomas treated by means of endoscopic transorbital superior eyelid approach in 3 referral centers over the last 4 yr.

Results: Fourteen cases were included in this study. In 4 patients, the transorbital endoscopic approach was combined with an endonasal route. Mean age was 51 and male-to-female ratio was 1:6. In 8 patients (57.1%), an intraorbital involvement was observed, 3 of them (21.4%) showed significant intraconal disease. No patient presented significant cavernous sinus infiltration. Main presenting symptoms were proptosis, diplopia, and visual impairment in 14, 6, and 6 patients, respectively. Mean proptosis improvement was 2 mm (standard deviation 2.3). We observed no major postoperative complications.

Conclusion: Our preliminary clinical experience seems to demonstrate that selected spheno-orbital meningiomas can be safely managed by means of an endoscopic transorbital route through a superior eyelid approach. Patients with orbital or cavernous sinus infiltration are at highest risk of persistence.

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.

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.

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.