Transpalpebral mini-orbitozygomatic approach for nonvascular skull base lesions: a single neurosurgeon's experience.

OBJECTIVE: The authors aim to describe the advantages, utility, and disadvantages of the transpalpebral mini-orbitozygomatic (MOZ) approach for tumors of the lateral and superior orbit, orbital apex, anterior clinoid, anterior cranial fossa, middle cranial fossa, and parasellar region. METHODS: The surgical approach from skin incision to closure is described while highlighting key technical and anatomical considerations, and cadaveric dissection demonstrates the surgical steps and focuses on important anatomy. Intraoperative images were included to supplement the cadaveric dissection. A retrospective review of adults who had undergone the MOZ approach for nonvascular pathology performed by a single neurosurgeon from 2017 to 2023 was included in this institutional review board-approved study. Descriptive statistics was used to summarize the data. Four representative cases were included to demonstrate the utility of the MOZ approach. RESULTS: The study included 65 patients (46 female, 19 male), average age 54.84 years, who had undergone transpalpebral MOZ surgery. Presenting symptoms included visual changes (53.8% of cases), vision loss (23.1%), diplopia (21.8%), and proptosis (13.8%). The optic nerve and optic chiasm were involved in 32.3% and 10.8% of cases, respectively. The most common pathology was meningioma (81.5% of cases), and gross-total resection was achieved in 50% of all cases. Major complications included an infection and a carotid injury. Improvement of preoperative symptoms was reported in 92.2% of cases. Visual acuity improved in 12 patients. The mean follow-up was 8.57 ± 8.45 months. CONCLUSIONS: The MOZ approach is safe and durable. The transpalpebral incision provides better cosmesis and functional outcomes than those of standard anterolateral approaches to the skull base. Careful consideration of the limits of the approach is paramount to appropriate application on a case-by-case basis. Further quantitative anatomical studies can help to define and compare the utility of the approach to open cranio-orbital and endoscopic transorbital approaches.

Anterolateral keyhole transorbital routes to the skull base: a comparative anatomical study.

OBJECTIVE: Although keyhole transorbital approaches are gaining traction, their indications have not been adequately studied comparatively. In this study the authors have defined them also as transwing approaches-meaning that they use the different facies of the sphenoid wing for cranial entry-and sought to compare the four major ones: 1) lateral orbitocraniotomy through a lateral canthal incision (LatOrb); 2) modified orbitozygomatic approach through a palpebral incision (ModOzPalp); 3) modified orbitozygomatic approach through an eyebrow incision (ModOzEyB); and 4) supraorbital craniotomy through an eyebrow incision (SupraOrb), coupled with its expanded version (SupraTransOrb). METHODS: Cadaveric dissections were performed at the neuroanatomy lab. To delineate the skull base exposure, four formalin-fixed heads were used, with two sides dedicated to each approach. The outer limits were assessed via image guidance and were mapped and illustrated accordingly. A fifth head was dissected purely endoscopically, just to facilitate an overview of the transwing concept. Qualitative features were also rigorously examined. RESULTS: The LatOrb proves to be more versatile in the middle cranial fossa (MCF), whereas the anterior cranial fossa (ACF) exposure is limited to a small area above the sphenoid ridge. An anterior clinoidectomy is possible; however, the exposure of the roof of the optic canal is suboptimal. The ModOzPalp adequately exposes both the ACF and MCF. Its lateral trajectory allows the inferior to superior view, yet there is restricted access to the medial anterior skull base (olfactory groove). The ModOzEyB also provides extensive exposure of the ACF and MCF, but has a more superior to inferior trajectory compared to the ModOzPalp, making it more appropriate for pathology reaching the medial anterior skull base or even the contralateral side. The anterior clinoidectomy is performed with improved visualization of the optic canal. The SupraOrb provides mainly anterior cranial base exposure, with minimal middle fossa. An anterior clinoidectomy can be performed, but without any direct observation of the superior orbital fissure. Some MCF access can be accomplished if the lateral sphenoid wing is drilled inferiorly, leading to its highly versatile variant, the SupraTransOrb. CONCLUSIONS: All the aforementioned approaches use the sphenoid wing as skull base corridor from a specific orientation point; hence these are designated as transwing approaches. Their peculiarities mandate careful case selection for the effective and safe completion of the surgical goals.

The biportal transorbital approach: quantitative comparison of the anterior subfrontal craniotomy, bilateral transorbital endoscopic, and microscopic approaches.

OBJECTIVE: The aim of this study was to assess the surgical use and applicability of a biportal bitransorbital approach. Single-portal transorbital and combined transorbital transnasal approaches have been used in clinical practice, but no study has assessed the surgical use and applicability of a biportal bitransorbital approach. METHODS: Ten cadaver specimens underwent midline anterior subfrontal (ASub), bilateral transorbital microsurgery (bTMS), and bilateral transorbital neuroendoscopic surgery (bTONES) approaches. Morphometric analyses included the length of the bilateral cranial nerves I and II, the optic tract, and A1; the area of exposure of the anterior cranial fossa floor; craniocaudal and mediolateral angles of attack (AOAs); and volume of surgical freedom (VSF; maximal available working volume for a specific surgical corridor and surgical target structure normalized to a height of 10 mm) of the bilateral paraclinoid internal carotid arteries (ICAs), bilateral terminal ICAs, and anterior communicating artery (ACoA). Analyses were conducted to determine whether the biportal approach was associated with greater instrument freedom. RESULTS: The bTMS and bTONES approaches provided limited access to the bilateral A1 segments and the ACoA, which were inaccessible in 30% (bTMS) and 60% (bTONES) of exposures. The average total frontal lobe area of exposure (AOE) was 1648.4 mm2 (range 1516.6-1958.8 mm2) for ASub, 1658.9 mm2 (1274.6-1988.2 mm2) for bTMS, and 1914.9 mm2 (1834.2-2014.2 mm2) for bTONES exposures, with no statistically significant superiority between any of the 3 approaches (p = 0.28). The bTMS and bTONES approaches were significantly associated with decreases of 8.7 mm3 normalized volume (p = 0.005) and 14.3 mm3 normalized volume (p < 0.001) for VSF of the right paraclinoid ICA compared with the ASub approach. No statistically significant difference in surgical freedom was noted between all 3 approaches when targeting the bilateral terminal ICA. The bTONES approach was significantly associated with a decrease of 105% in the (log) VSF of the ACoA compared with the ASub (p = 0.009). CONCLUSIONS: Although the biportal approach is intended to improve maneuverability within these minimally invasive approaches, these results illustrate the pertinent issue of surgical corridor crowding and the importance of surgical trajectory planning. A biportal transorbital approach provides improved visualization but does not improve surgical freedom. Furthermore, although it affords impressive anterior cranial fossa AOE, it is unsuitable for addressing midline lesions because the preserved orbital rim restricts lateral movement. Further comparative studies will elucidate whether a combined transorbital transnasal route is preferable to minimize skull base destruction and maximize instrument access.

Surgical Treatment of Complex Craniofacial Fractures.

OBJECTIVE: Severe craniofacial fractures may present different needs in treating intracranial lesions over facial injuries. This paper examines the results of our strategy, consisting of a single-stage combined neurosurgical-maxillofacial treatment. METHODS: A retrospective review was conducted of 33 consecutive patients with complex fractures of the anterior cranial fossa and facial skeleton, who required elective surgery for craniofacial reconstruction. Patients who required emergency surgery for intracranial clots or penetrating wounds were excluded. In all cases, all or almost all the anterior skull-base was injured with compound fractures of the frontal sinus, the orbital roofs, the lamina cribrosa, and the planum sphenoidale. In all cases, the prioritization of treatment was carefully discussed, and surgical timing and strategy were agreed. RESULTS: There was 1 dead. Olfactory injuries were always found intraoperatively. There were no mucoceles, CSF-leak recurrences, cranial infections, or neurologic worsening. The functional and neurologic results were highly satisfactory. CONCLUSIONS: The one-stage surgical treatment of complex craniofacial fractures has numerous advantages, including the possibility of reducing facial fractures without the risk of CSF leaks. It also eliminates the need for repeated procedures in fragile patients, and the need to dismantle the facial reconstruction if the skull base repair is performed later. The main issue is the surgical timing, considering that the maxillofacial surgeon usually favors early facial repair, whereas the neurosurgeon generally prefers delayed manipulation of the contused frontal lobes. A timeframe of 10-14 days after trauma may be a good compromise for safe procedures with excellent neurologic and functional outcomes.

Frontal trans-sinusal approach: how I do it.

BACKGROUND: Anterior skull base lesions could be reached by different approaches (subfrontal, pterional, interhemispheric, etc.). In selected cases, the frontal trans-sinusal approach is an effective alternative to conventional techniques. METHODS: We present our technique to perform a frontal trans-sinusal approach in a patient affected by a large olfactory groove meningioma. DISCUSSION-CONCLUSION: The frontal trans-sinusal approach allows to approach safely lesions of the median anterior cranial fossa. This approach provides lower brain retraction, easier access to olfactory grooves, and earlier tumor devascularization. However, it remains limited to patients with large-sized frontal sinuses and entails some postoperative risks such as mucocele or CSF leak.

Endoscopy-Assisted Microneurosurgery for Sella and Optic Foramen Invading Anterior Cranial Fossa Base Meningiomas.

BACKGROUND: Anterior skull base meningioma produces symptoms as a result of mass effect and neurovascular compression. The bony anatomy of the anterior skull base is complex and houses the critical cranial nerves and vessels. Traditional microscopic approaches remove these tumors effectively but require extensive brain retraction and bone drilling. Endoscope assistance offers the advantages of a smaller incision, less brain retraction, and bone drilling. The most significant advantage of endoscope-assisted microneurosurgery for lesions invading the sella and optic foramen is the complete resection of the sellar and foraminal components frequently responsible for recurrence. OBJECTIVE: In this report, we describe the technique of endoscope-assisted microneurosurgical resection of anterior skull base meningiomas invading the sella and foramen. METHODS: We present 10 cases and 3 case examples of endoscope-assisted microneurosurgery for meningiomas invading the sella and optic foramen. This report presents the operating room setup and surgical details to resect sellar and foraminal tumors. The surgical procedure is presented as a video. RESULTS: Endoscope-assisted microneurosurgery yielded excellent clinical and radiologic results and no recurrence at the last follow-up of meningiomas invading the sella and optic foramen. The present article discusses the challenges faced with endoscope-assisted microneurosurgery, techniques, and challenges in the procedure. CONCLUSIONS: Endoscope assistance enables complete tumor excision under vision with less retraction and bone drilling in anterior cranial fossa meningioma, invading the chiasmatic sulcus, optic foramen, and sella. The mixed use of microscope and endoscope makes it safer and saves time and is like bringing out the best of both worlds.

Endoscope-Controlled High Frontal Approach for Dural Arteriovenous Fistula in Anterior Cranial Fossa.

BACKGROUND: Currently, surgical obliterations are a mainstay for treating dural arteriovenous fistula (DAVF) in the anterior cranial fossa (ACF), which has high risks of hemorrhage and functional disorder. By introducing an endoscope into a high frontal approach and utilizing its advantages, we attempted to establish it as a new surgical procedure that eliminates the drawbacks of various approaches that have been used to date. METHODS: By using 30 clinical datasets of venous-phase head computed tomography angiogram, measurements and comparisons on a 3-dimensional workstation were performed to identify the appropriate positioning of keyhole craniotomy for endoscope-controlled high frontal approach (EHFA). Based on these data, a cadaver-based surgery was simulated to verify the feasibility of EHFA and develop an efficient procedure. RESULTS: In EHFA, though raising the position of the keyhole craniotomy made the operative field deeper, significant advantages were obtained in the angle between the operative axis and the medial-anterior cranial base and the amount of bone removal required at the anterior edge of craniotomy. Minimally invasive EHFA, performed through a keyhole craniotomy without opening the frontal sinus, proved to be feasible on 10 sides of 5 cadaver heads. Moreover, 3 patients with DAVF in ACF were successfully treated by clipping the fistula via EHFA. CONCLUSIONS: EHFA, which provided a direct corridor to the medial ACF at the level of the foramen cecum and crista galli and the minimum necessary operative field, was found to be a suitable procedure for clipping the fistula of DAVF in ACF.

Combined Endoscopic Endonasal and Transpalatal Repair of Congenital Anterior Cranial Fossa Agenesis.

BACKGROUND: Congenital basal meningoceles and encephaloceles are rare pathologies that may present in isolation or with characteristic-associated clinical features. Rarely, children with congenital midline defects may present with massive encephaloceles secondary to anterior cranial fossa agenesis. Traditionally, transcranial approaches with frontal craniotomies were used to reduce the herniated contents and repair the skull base defect. However, high rates of morbidity and mortality associated with craniotomies have favored the development and adoption of less-invasive techniques. OBJECTIVE: To present a novel technique for combined endoscopic endonasal and transpalatal repair of a giant basal meningocele through an extensive sphenoethmoidal skull base defect. METHODS: A representative case of congenital anterior cranial fossa agenesis with a giant meningocele was selected. Clinical and radiological presentations were reviewed, and the intraoperative surgical technique was documented and recorded. RESULTS: A surgical video highlighting each surgical step was included to complement the description of the technique. The surgical outcome from the selected case is also presented. CONCLUSION: This report describes a combined endoscopic endonasal and transpalatal approach to repair an extensive anterior skull base defect with herniation of intracranial content. This technique capitalizes on the advantages of each approach to address this complex pathology.

Transpalpebral Eyelid Approach for Supraorbital Frontal Craniotomy and Access to the Anterior Cranial Fossa.

SUMMARY: The transpalpebral eyelid approach is an innovative alternative to traditional incisions for exposure of the anterior cranial fossa for neurosurgery. However, there is a paucity of data on this surgical technique in the plastic surgery literature for accessing the anterior cranial fossa. A retrospective review was performed of patients who underwent supraorbital frontal craniotomy using an anterior skull base approach with transpalpebral exposure over 8 years by a single plastic surgeon. Surgical techniques, medical comorbidities, intraoperative complications, and long-term complications were assessed. Twenty patients (mean age 52 ± 12 years, 55% male, 45% female) underwent supraorbital frontal craniotomy using an anterior skull base approach with upper transpalpebral exposure. Operative indications included the following: 75% had anterior communicating aneurysms, with a mean aneurysm size of 5.36 ± 1.91 mm; 10% had meningiomas; 10% had dural fistulas; and 5% had an orbital hemangioma. A total of 60% of patients had a smoking history. No intraoperative complications were encountered, and no cases required conversion to a traditional open approach. Mean length of hospital stay was 3.2 ± 1.5 days. Postoperative imaging revealed no residual or recurrent pathology. Mean follow-up time was 62.2 ± 30.6 months. No long-term neurologic or ophthalmologic complications or infections occurred. No forehead paresthesias, brow ptosis, or brow paralysis were noted. The transpalpebral technique is a safe, minimally invasive method to approach lesions of the anterior cranial fossa. Successful application may require appropriate management of the frontal sinus and supraorbital nerve. This approach does not limit neurosurgical access or results and led to no neurosurgical complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Natural history, angiographic presentation and outcomes of anterior cranial fossa dural arteriovenous fistulas.

BACKGROUND: Anterior cranial fossa dural arteriovenous fistulas (ACF-dAVFs) are aggressive vascular lesions. The pattern of venous drainage is the most important determinant of symptoms. Due to the absence of a venous sinus in the anterior cranial fossa, most ACF-dAVFs have some degree of drainage through small cortical veins. We describe the natural history, angiographic presentation and outcomes of the largest cohort of ACF-dAVFs. METHODS: The CONDOR consortium includes data from 12 international centers. Patients included in the study were diagnosed with an arteriovenous fistula between 1990-2017. ACF-dAVFs were selected from a cohort of 1077 arteriovenous fistulas. The presentation, angioarchitecture and treatment outcomes of ACF-dAVF were extracted and analyzed. RESULTS: 60 ACF-dAVFs were included in the analysis. Most ACF-dAVFs were symptomatic (38/60, 63%). The most common symptomatic presentation was intracranial hemorrhage (22/38, 57%). Most ACF-dAVFs drained through cortical veins (85%, 51/60), which in most instances drained into the superior sagittal sinus (63%, 32/51). The presence of cortical venous drainage predicted symptomatic presentation (OR 9.4, CI 1.98 to 69.1, p=0.01). Microsurgery was the most effective modality of treatment. 56% (19/34) of symptomatic patients who were treated had complete resolution of symptoms. Improvement of symptoms was not observed in untreated symptomatic ACF-dAVFs. CONCLUSION: Most ACF-dAVFs have a symptomatic presentation. Drainage through cortical veins is a key angiographic feature of ACF-dAVFs that accounts for their malignant course. Microsurgery is the most effective treatment. Due to the high risk of bleeding, closure of ACF-dAVFs is indicated regardless of presentation.

[Keyhole surgery for giant basal brain tumors. Theoretical explanation with an example of trans-eyebrow subraorbital approach]. / Aktual'nost' keyhole-dostupov v khirurgii gigantskikh opukholei osnovaniya golovnogo mozga. Teoreticheskoe obosnovanie na primere chrezbrovnogo supraorbital'nogo dostupa.

BACKGROUND: Improvement of modern neurosurgical technology has given rise to keyhole surgery for a wide range of pathologies. Supraorbital trans-eyebrow approach has been described in detail for small tumors of anterior cranial fossa and suprasellar neoplasms. Can we use this small and less traumatic approach for a more complex tumor extending beyond the suprasellar region? OBJECTIVE: To analyze own experience of surgical treatment of large and giant parasellar tumors via supraorbital approach, to identify the principles of such operations, indications and possible limitations. MATERIAL AND METHODS: There were 58 resections of parasellar tumors via mini-supraorbital approach had been performed between 2016 and 2021 at the 2nd pediatric neurosurgical department. We selected 42 patients with large and giant tumors extending beyond the chiasmal-sellar zone and causing occlusive hydrocephalus (mean volume 44.2 cm3). Preoperative status of patients, postoperative clinical data and logistics of in-hospital treatment were analyzed. RESULTS: Total resection was performed in all cases. No redo surgeries or revisions were required. There were no cases of wound infection, CSF leakage and damage to large vessels. CONCLUSION: We standardized planning of surgeries for large neoplasms considering available knowledge about the nature of diseases, analysis of clinical and X-ray data, goals and objectives of surgery. The reader is offered a theoretical substantiation of applicability of keyhole surgery for chiasmal-sellar tumors on the example of well-known mini-supraorbital approach. We gave certain advices on planning such operations and illustrated clinical examples.

Quantitative Anatomic Comparison of Endoscopic Transnasal and Microsurgical Transcranial Approaches to the Anterior Cranial Fossa.

BACKGROUND: Several microsurgical transcranial approaches (MTAs) and endoscopic transnasal approaches (EEAs) to the anterior cranial fossa (ACF) have been described. OBJECTIVE: To provide a preclinical, quantitative, anatomic, comparative analysis of surgical approaches to the ACF. METHODS: Five alcohol-fixed specimens underwent high-resolution computed tomography. The following approaches were performed on each specimen: EEAs (transcribriform, transtuberculum, and transplanum), anterior MTAs (transfrontal sinus interhemispheric, frontobasal interhemispheric, and subfrontal with unilateral and bilateral frontal craniotomy), and anterolateral MTAs (supraorbital, minipterional, pterional, and frontotemporal orbitozygomatic approach). An optic neuronavigation system and dedicated software (ApproachViewer, part of GTx-Eyes II-UHN) were used to quantify the working volume of each approach and extrapolate the exposure of different ACF regions. Mixed linear models with random intercepts were used for statistical analyses. RESULTS: EEAs offer a large and direct route to the midline region of ACF, whose most anterior structures (ie, crista galli, cribriform plate, and ethmoidal roof) are also well exposed by anterior MTAs, whereas deeper ones (ie, planum sphenoidale and tuberculum sellae) are also well exposed by anterolateral MTAs. The orbital roof region is exposed by both anterolateral and lateral MTAs. The posterolateral region (ie, sphenoid wing and optic canal) is well exposed by anterolateral MTAs. CONCLUSION: Anterior and anterolateral MTAs play a pivotal role in the exposure of most anterior and posterolateral ACF regions, respectively, whereas midline regions are well exposed by EEAs. Furthermore, certain anterolateral approaches may be most useful when involvement of the optic canal and nerves involvement are suspected.

[Basic Concept of Skull Base Reconstructive Surgery].

In most cases of anterior cranial fossa defects, the cranial cavity and the nasal cavity are connected, and it is necessary to reconstruct the skull base in a narrow sense to separate both cavities. If the surgical purpose is only separation, reconstruction with a pedicled local flap is often possible. As other surgical purposes such as the reconstruction of surrounding tissues are added, the transplanted tissue volume becomes insufficient, and free tissue transfer is required. In the case of a defect in the middle cranial fossa, the cranial cavity is not always connected with the nasal cavity because it is far from the nasal cavity and oral cavity. In this case, it is skull base reconstruction in a broad sense whose purpose is other than separation. There are many factors such as facial soft tissue augmentation and facial nerve reconstruction as the surgical purpose, and the more the purposes, the more likely it is that free tissue transfer will be required. In patients with anterior and middle cranial fossa defects, both cavities are connected and the resected tissue volume is large, so free tissue transfer is selected in most cases, except for a few benign diseases.

Endovascular treatment of anterior cranial base dural arteriovenous fistulas as a first-line approach: a multicenter study.

OBJECTIVE: Anterior cranial fossa dural arteriovenous fistulas (DAVFs) have been almost exclusively considered as surgical lesions. However, new advances in endovascular technology have made the endovascular treatment (EVT) of ethmoidal DAVFs feasible. The aim of this study was to report the clinical and angiographic outcomes of patients harboring DAVFs of the anterior cranial fossa who had undergone EVT as a first-line approach. METHODS: This was a retrospective study of a consecutive series of patients harboring anterior cranial base DAVFs who had undergone EVT as a first-line approach at four institutions. Angiographic follow-up was performed at 6 months. Immediate and late serious clinical events were assessed during follow-up, including death and stroke. Special emphasis was given to visual status before and after the treatment. RESULTS: Between 2008 and 2020, 37 patients with ethmoidal DAVFs were admitted to the participating centers. In 2 patients, EVT was not attempted; therefore, 35 patients underwent EVT as a first-line procedure. An isolated transarterial approach was performed in 19 (54.3%) patients. The transvenous approach was performed exclusively in 12 (34.3%) patients, and combined access was used in 4 (11.4%) patients. The most frequently used arterial access route was the ophthalmic artery in 82.6% of the patients. Immediately, complete angiographic occlusion was achieved in 31 (91.2%) of 34 patients whose treatment was accomplished. Six-month control angiography revealed that 30 (88.2%) DAVFs were totally occluded. Complications occurred in 3 (8.8%) patients, including 1 (2.9%) patient who had central retinal artery occlusion. No significant difference in complications or occlusion rates was noted between the transarterial and transvenous approaches. CONCLUSIONS: Most anterior cranial base DAVFs can be successfully treated via an endovascular approach. Neurological and visual complications are rare, even if the ophthalmic artery is used as the primary access route. Efforts should be focused on prospectively comparing the results of EVT and surgical management.

Transorbital Approach for Olfactory Groove Meningioma.

The transorbital endoscopic approach has been increasingly employed in the management of skull base disease.1-4 We present a case of a 48-year-old woman with a 2-month history of progressively worsening headache referred to our neurosurgery division after a new-onset generalized seizure. On examination, she was found to have diminished olfaction with no additional findings, including no visual or cognitive deficits. Preoperative imaging revealed a large anterior fossa mass originating at the left olfactory groove with leftward extension and prominent anterior and posterior ethmoidal arterial feeders. A left-sided transorbital approach was planned to address the tumor. The lesion was resected without incident using a pure transorbital endoscopic technique. The microscope was brought into the field at the end of the procedure to aid with hemostasis of the surgical bed. The patient recovered without surgical complications. Histopathology revealed a World Health Organization grade I olfactory groove meningioma. Postoperative imaging confirmed gross total tumor resection without evidence of recurrence. This case highlights the application of the transorbital endoscopic approach in the management of anterior cranial base tumors. Advantages of this approach include minimal invasive access, avoidance of brain retraction, and ease for early tumor devascularization.

Keyhole Supraorbital-Eyebrow Approach for Resection of an Olfactory Groove Meningioma with Intraoperative Endoscopic Assistance.

The authors present the case of a 52-year-old male with a history of new-onset seizures who presented in status epilepticus. Computed tomography and magnetic resonance imaging demonstrated an olfactory groove mass. A keyhole supraorbital-eyebrow approach assisted with a microinspection tool was performed for tumor resection.1-5 A Simpson grade 2 tumor resection was achieved, and histopathology revealed a World Health Organization grade I olfactory groove meningioma. Postoperative and follow-up course has been unremarkable, with early postoperative imaging demonstrating no residual tumoral mass. The operative video highlights the advantages of using the microinspection tool for the visualization of deep lesions.

Recurrent epistaxis due to cribriform plate dural arteriovenous fistula: are they related? Should the treatment be from venous, pial or arterial side?

PURPOSE: Dural arteriovenous fistula (DAVF) of the anterior cranial fossa with cortical venous reflux is an aggressive neurovascular entity with a high rate of intracranial bleeding. Only two cases of anterior cranial fossa DAVF presenting with epistaxis alone have been reported. Endovascular approaches have emerged as the primary and safer treatment modality for most DAVFs. Certain fistulas are better treated with open surgical approaches and disconnection. CASE DESCRIPTION: A 55 years old male presented with the history of multiple episodes of severe epistaxis. Cerebral angiography revealed an anterior cranial fossa DAVF of the cribriform plate with cortical venous reflux and a venous varix. The patient was successfully managed with a bifrontal craniotomy and disconnection from the arterial side. CONCLUSION: Atypical or severe epistaxis may arise from a DAVF. Surgical arterial disconnection my be a curative treatment option.

The different concepts of surgical managements between anterior and lateral skull base reconstructions based on surgical purposes.

OBJECTIVE: Anterior and middle cranial fossa defects require different strategies, depending on their anatomical location. The aim of this study was to elucidate the surgical managements for the defects based on surgical purposes and to clarify the conceptional differences relating to anterior and lateral skull base reconstructions. METHODS: This study included patients who had undergone reconstructive surgery for anterior or middle cranial fossa defects in our institution between July 2008 and June 2019. It consisted of 66 patients who had been subject to anterior skull base reconstructions, and 84 patients who had experienced lateral skull base reconstructions. The medical records were examined retrospectively, and the surgical purposes and procedures performed were reviewed. The surgical purposes were divided into four groups: Separation, Restoration, Augmentation, and Coverage. RESULTS: Regarding anterior skull base reconstructions, the Separation group included 65 patients, who represented 98% of this category. There were 26 cases in the Separation-only group, 20 of which were reconstructed with locoregional flaps, and 6 of which with free tissue transfers. A Combination group, which consisted of Separation and Other purposes, consisted of 40 cases. Within this group, 5 cases were reconstructed with locoregional flaps, and 35 with free tissue transfers. Regarding lateral skull base reconstructions, the Separation group included 34 patients, who represented 40% of this category. The rate of the Other purposes represented the majority. In the Separation-only group of 24 patients, 16 cases were reconstructed with locoregional flaps and 8 cases with free tissue transfers. In the Combination group of 10 patients, 2 cases were reconstructed with locoregional flaps and 8 cases with free tissue transfers. In groups other than the Separation group, 27 cases were reconstructed with locoregional flaps and 23 cases with free tissue transfers. CONCLUSION: In most anterior cranial fossa defect cases, the surgical purpose is separation. In middle cranial fossa defect cases, there are many cases in which the surgical purpose is not separation. In the Separation groups, relating to both anterior and lateral skull base reconstructions, the use of locoregional flaps was an effective measure. Free tissue transfers were required in many cases of the Combination group. Outside of the Separation group associated with lateral skull base reconstructions, the use of locoregional flaps and free tissue transfers were almost equal in proportion, and the selection of reconstructive procedures tended to change from locoregional flaps to large free flaps with increase in the numbers of surgical purposes.

Sarcoidosis Mimicking Skull Base Meningioma

Sarcoidosis is a systemic disease characterized by granulomatous inflammation. Pulmonary and lymphatic granulomatous involvement are common.We present a rare case report of involvement of the central nervous system affecting the ocular region and mimicking optic nerve sheath meningioma. We report the case of a 79-year-old female patient with progressive visual impairment with an evolution of 4 years. Amagnetic resonance imaging scan of the cranium with gadolinium and intense homogeneous contrast enhancement revealed an expansive lesion in the right optic nerve, at the height of the optic canal. The patient was submitted to the neurosurgical approach with lesion biopsy, which showed sarcoidosis of the central nervous system. Due to the rarity of central nervous system involvement, the diagnosis of this pathologymay unfortunately be postponed. The present article aims to elucidate this pathology as a differential diagnosis of retro-orbital tumors.