Extradural Anterior Clinoidectomy Research Articles

Feasibility and efficacy of endoscopic transorbital optic canal decompression for meningiomas causing compressive optic neuropathy.

The endoscopic transorbital approach (ETOA) and transorbital anterior clinoidectomy have been suggested as novel procedures through which to reach the superolateral compartments of the orbit, allowing optic canal decompression. However, there is limited literature describing the technical details and surgical outcomes of these procedures. In this study, the authors aimed to analyze the feasibility and efficacy of endoscopic transorbital decompression of the optic canal through anterior clinoidectomy for compressive optic neuropathic lesions. Between 2016 and 2022, the authors performed ETOA for compressive optic neuropathic lesions in 14 patients. All these patients underwent transorbital anterior clinoidectomy through the surgically defined "intraorbital clinoidal triangle," which is composed of the roof of the superior orbital fissure, the medial margin of the optic canal, the medial border of the superior orbital fissure, and the optic strut. Demographic data, tumor characteristics, pre- and postoperative imaging, pre- and postoperative visual examinations, and surgical outcomes were retrospectively reviewed. The mean age at the time of ETOA was 53.3 years (range 41-64 years), and the mean follow-up was 16.8 months (range 6.7-51.4 months). The inclusion criterion in this study was having a meningioma (14 patients). In the preoperative visual function examination, 7 patients with a meningioma showed progressive visual impairment. After endoscopic transorbital optic canal decompression, visual function improved in 5 patients, remained unchanged in 8 patients, and worsened in 1 patient. No new-onset neurological deficit was associated with ETOA and anterior clinoidectomy in any patients. Endoscopic transorbital decompression of the optic canal with extradural anterior clinoidectomy is a safe and feasible technique that avoids significant injury to the clinoidal internal carotid artery and surrounding neurovascular structures.

Exoscopic extradural anterior clinoidectomy.

Extradural anterior clinoidectomy is a resourceful technique to decompress the optic nerve as well as increase exposure of the parasellar region during extensive approaches. Despite requiring adjunctive epidural bone work, this technique allows safe optic nerve mobilization and early devascularization for anterior clinoidal meningioma resection. This 2D operative video describes right optic nerve decompression by extradural anterior clinoidectomy and subsequent resection of a right Al-Mefty type III clinoid meningioma under exoscope magnification. The patient was a 50-year-old woman with a 1-year history of right visual acuity impairment and papillary atrophy. The exoscope allows a 360° view around the anterior clinoid, improving maneuverability. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23118.

Transorbital Exposure of the Internal Carotid Artery: A Detailed Anatomic and Quantitative Roadmap for Safe Successful Surgery.

The superior eyelid endoscopic transorbital approach has rapidly gained popularity among neurosurgeons for its advantages in the treatment, in a minimally invasive fashion, of a large variety of skull base pathologies. In this study, an anatomic description of the internal carotid artery (ICA) is provided to identify risky zones related to lesions that may be approached using this technique. In this framework, a practical roadmap can help the surgeon to avoid potentially life-threatening iatrogenic vascular injuries. Eight embalmed adult cadaveric specimens (16 sides) injected with a mixture of red latex and iodinate contrast underwent superior eyelid transorbital endoscopic approach, followed by interdural dissection of the cavernous sinus, extradural anterior clinoidectomy, and anterior petrosectomy, to expose the entire "transorbital" pathway of the ICA. Furthermore, the distance of each segment of the ICA explored by means of the superior eyelid endoscopic transorbital approach was quantitatively analyzed using a neuronavigation system. We exposed 4 distinct ICA segments and named the anatomic window in which they are displayed in accordance with the cavernous sinus triangles distribution of the middle cranial fossa: (1) clinoidal (Dolenc), (2) infratrochlear (Parkinson), (3) anteromedial (Mullan), and (4) petrous (Kawase). Critical anatomy and key surgical landmarks were defined to further identify the main danger zones during the different steps of the approach. A detailed knowledge of the reliable surgical landmarks of the course of the ICA as seen through an endoscopic transorbital route and its relationship with the cranial nerves are essential to perform a safe and successful surgery.

Minimally Invasive Posterolateral Transcavernous Transtentorial Approach: 2-Dimensional Operative Video.

MIPLATTA uses a "key-exposure" concept aligning a small minipterional craniotomy with variations of extradural transcavernous transtentorial corridors to access the skull base. Safety and efficiency depend on mastery of the anterior clinoid process (ACP) and cavernous sinus (CS). Preoperative planning includes assessment of ACP pneumatization; tumor epicenter relative to the CS, ACP, and tentorium; and pattern of venous drainage (role of vein of Labbé). 1. Interfascial flap for facial nerve preservation.2. Minipterional craniotomy with extradural anterior clinoidectomy.3. Variable Transcavernous dissection according to the Hakuba method4. Dural opening parallel to the Sylvian fissure.5. Transtentorial with possible Kawase.6. Closure with autologous graft into the clinoidal triangle and water-tight dural closure. Incomplete release of the optic and oculomotor nerves during anterior clinoidectomy may lead to deficits. Insufficient caudal extent of the craniotomy may cause undue retraction on Labbé and a temporal lobe infarct. Thorough anatomic knowledge of the CS is a key for catastrophe prevention. 1. Basic MIPLATTA with minipterional and extradural anterior clinoidectomy (Hakuba approach) for optic nerve decompression and parasellar lesions.2. Extended MIPLATTA adds oculomotor nerve transposition and cavernous sinus peeling for middle fossa, sphenoid ridge, and giant clinoid tumors.3. Full MIPLATTA adds Kawase and internal auditory canal exposure with endoscopic-assisted microsurgery for tumors invading the posterior fossa.The patients consented to both surgery and publication of their images. Permission was obtained appropriately for the publication of the cadaveric images. The anatomic images and animations in the surgical anatomy section of the video are sole property of www.neurosurgicalanatomy.com and Neurosurgical Anatomy by Arnau Benet, MD, who shall retain copyright, and used with permission.

How I do it: The microsurgical clipping of the giant paraclinoid aneurysm using the retrograde suction decompression technique.

Paraclinoid aneurysms account for 5.4% of all intracranial aneurysms. Giant aneurysms are found in 49% of these cases. The 5-year cumulative rupture risk is 40%. Microsurgical treatment of paraclinoid aneurysms is a complex challenge that requires a personalized approach. Extradural anterior clinoidectomy and optic canal unroofing were performed in addition to orbitopterional craniotomy. Falciform ligament and distal dural ring transection provided the internal carotid artery and optic nerve mobilization. Retrograde suction decompression was used to soften the aneurysm. Clip reconstruction was performed using tandem angled fenestration and parallel clipping techniques. Orbitopterional approach with extradural anterior clinoidectomy combined with retrograde suction decompression technique is a safe and effective modality for treatment of giant paraclinoid aneurysms.

Looking Beyond the Anterolateral Skull Base with Frontotemporal Dural Fold Unlocking and Extradural Clinoidectomy: A Series of 17 Cases Deciphering the Translation from a Cadaver to Real, and Real to Pathologically Distorted Anatomy.

This article aims to discuss the surgical nuances and major adjustments necessary in unlocking the frontotemporal dural fold (FTDF) and extradural anterior clinoidectomy (EDAC) in actual cases, allowing translation from the cadaveric to a clinical scenario. We retrospectively reviewed the technical details of 17 procedures over 8 years, where both the initial steps (FTDF unlocking and EDAC) were performed. Lesions involving or extending to the anterolateral skull base, like the suprasellar cistern, optico-carotid cistern, interpeduncular cistern, petrous apex, and cavernous sinus, were included. The clinical data of the patients were retrieved retrospectively from the hospital information system (HIS) and in-patient records. This study was approved as a multicenter individual project with IEC No: 2020-342-IP-EXP-34. An illustrated note of the common steps and outcome of the 17 procedures of unlocking the FTDF and EDAC done is presented. The technique provided adequate exposure in performing aneurysmal clipping (posterior communicating artery [P. com], basilar top, and superior hypophyseal artery [SHA] aneurysm), giant pituitary adenoma (Wilson Hardy grade 4E, n = 2), fifth nerve schwannoma (n = 4), right Meckel's cave melanoma, cavernous hemangioma (n = 4), petroclival meningioma (n = 2), and clival chordoma. Temporary and permanent cranial nerve palsy as a procedure-related complication was seen in 11.8% (n = 2) each. Complete excision was achieved in 13 (n = 13/14) patients with tumors. FTDF unlocking and EDAC are elegant procedures providing reasonable access to the anterolateral skull base for myriad pathologies. Brain bulge, cavernous sinus bleeding, and losing the plane of dural duplication were significant challenges in switching from cadaveric to a clinical scenario.

Cranio-Orbital Pretemporal Approach With Extradural Anterior Clinoidectomy and Optic Nerve Release for Microsurgical Resection of Large Tuberculum Sellae Meningioma-Reversal of Preoperative Bilateral Blindness: 2-Dimensional Operative Video.

Cranio-Orbital Pretemporal Approach With Extradural Anterior Clinoidectomy and Optic Nerve Release for Microsurgical Resection of Large Tuberculum Sellae Meningioma-Reversal of Preoperative Bilateral Blindness: 2-Dimensional Operative Video.

Endoscopic transorbital extradural anterior clinoidectomy: A stepwise surgical technique and case series study [SevEN-013

BackgroundAnterior clinoidectomy is an important procedure for approaching the central skull base lesions. However, anterior clinoidectomy through the endoscopic transorbital approach (ETOA) still has limitations due to technical difficulties and the structural complexity of the anterior clinoid process (ACP). Therefore, the authors designed a stepwise surgical technique of extradural anterior clinoidectomy through the ETOA. The purpose of this study was to evaluate the feasibility of this technique.MethodsAnatomical dissections were performed in 6 cadaveric specimens using a neuroendoscope and neuro-navigation system. The extradural anterior clinoidectomy through the ETOA was performed stepwise, and based on the results, this surgical technique was performed in the 7 clinical cases to evaluate its safety and efficiency.ResultsEndoscopic extradural anterior clinoidectomy was successfully performed in all cadaveric specimens and patients using the proposed technique. This 5-step technique enabled detachment of the lesser wing of sphenoid bone from the ACP, safe unroofing of the optic canal, and resection of the optic strut without injuring the optic nerve and internal carotid artery. Since the sequential resection of the 3 supporting roots of the ACP was accomplished safely, anterior clinoidectomy was then successfully performed in all clinical cases. Furthermore, no complications related to the anterior clinoidectomy occurred in any clinical case.ConclusionWe designed a stepwise surgical technique that allows safe and efficient anterior clinoidectomy through the ETOA. Using this technique, extradural anterior clinoidectomy can be accomplished under direct endoscopic visualization with low morbidity. Since this technique is applicable to the central skull base surgery where anterior clinoidectomy is necessary, it expands the application of the ETOA.

Pituitary Stalk Hemangioblastoma: Complete Resection through Orbitozygomatic Approach with Extradural Anterior Clinoidectomy.

Background Pituitary stalk hemangioblastomas (PSHBLs) are rare vascular tumors and their surgical removal is challenging due to the proximity with several fundamental anatomic structures including the pituitary stalk, third ventricle, hypothalamus, and optic pathways. To date, only few descriptions of transcranial and transsphenoidal approaches for PSHBLs have been reported in the literature and none in video, with suboptimal outcomes in terms of pituitary function preservation. Here, we describe the use of orbitozygomatic (OZ) craniotomy with extradural anterior clinoidectomy (EAC) for the removal of a PSHBL with preservation of the pituitary stalk. Case Description A 60-year-old woman with a sporadic symptomatic HBL of the pituitary stalk, with the typical features of avid contrast enhancement on T1- and flow voids on T2-weighted magnetic resonance imaging (MRI) images, underwent a right OZ craniotomy with EAC. The choice of the approach was guided by the necessity of exposing the floor of the 3rd ventricle and infundibulum, where the origin of the pituitary stalk is better appreciated and preserved, without brain retraction. EAC was deemed important due to the necessity of widening the right carotico-oculomotor and opticocarotid triangles and gaining access to the ophthalmic segment of the internal carotid artery, origin of the superior hypophyseal artery, and the tumor supply. The postoperative MRI confirmed gross tumor removal with preservation of the pituitary stalk and no tumor recurrence after 2 years of follow-up. Conclusion OZ craniotomy coupled with EAC facilitates surgical removal of PSHBLs thus augmenting the chances of pituitary function preservation. The link to the video can be found at https://youtu.be/hH65W937RGY .

Extradural anterior clinoidectomy versus endoscopic transplanum-transcavernous approach to the paraclinoid region: quantitative anatomical exposure analysis.

Transcranial anterior clinoidectomy is a conventional microsurgical approach for treatment of paraclinoid aneurysms. The endoscopic endonasal approach (EEA) is an alternative method for clipping intracranial aneurysms. No analysis has been conducted to anatomically compare approaches with respect to treating paraclinoid aneurysms. The surgical anatomical exposures of the paraclinoid region during transcranial extradural anterior clinoidectomy (EAC) and the endoscopic endonasal transplanum-cavernous approach (EETC) are described and quantitatively assessed. Seven cadaveric heads underwent EAC and EETC. Measurements included the area of exposure, volume of surgical freedom, angle of attack, ophthalmic artery (OphA) origin, and coronal exposure angle of the internal carotid artery (ICA). The EETC provided a larger area of exposure than the EAC (100.1±24.9 vs 76.1±12.9 mm2, p = 0.04). The EAC provided a higher volume of surgical freedom and greater angle of attack than the EETC in all neurovascular parameters, including the OphA, superior hypophyseal artery (SHA), distal ICA, and distal dural ring (all p < 0.001). The OphA origin was intradural in 85.7% and extradural in 14.3% of specimens. With regard to the coronal angle of exposure, the EAC exposed the OphA and SHA in the upper lateral quadrant (67.9±7.8° and 80.6±4.5°, respectively) and the distal ICA in the upper medial and upper lateral quadrants (92±7.5°). The EEA exposed the OphA, SHA, and distal ICA in the upper medial and lower medial quadrants (130.4±10.7°, 68.4±10.8°, and 58±11.4°, respectively). The EAC and EETC each offer specific advantages for paraclinoid region exposure. The EAC is appropriate for paraclinoid aneurysms that occur at the dorsolateral surface of the paraclinoid ICA. The EETC is an alternative approach for aneurysms that occur along medial surface of the paraclinoid ICA (e.g., carotid cave and SHA aneurysms). The EETC provides greater surgical exposure to the medial aspect of the paraclinoid ICA.

Predictors of visual function after resection of skull base meningiomas with extradural anterior clinoidectomy

Skull base meningiomas threatening the optic nerves may require performing an extradural anterior clinoidectomy (EAC) to optimally decompress the optic pathways. The present study evaluated the functional results and morbidity after surgical resection of skull base meningiomas including EAC, focusing on visual acuity (VA) and oculomotricity. Eighty-seven consecutive patients harboring skull base meningiomas who underwent surgical resection that included an EAC between 2003 and 2020 were retrospectively analyzed (86% women, median age 53years). Decreased visual acuity (DVA) was graded as functional (VA ≥ 5/10) and nonfunctional (VA < 5/10). Statistical analyses were performed on VA and oculomotor nerve (OcN) dysfunction. Ninety surgical procedures were performed. Meningiomas were located at the anterior clinoid process (39%), cavernous sinus (31%), and spheno-orbital (30%) levels. Patients with a preoperative functional vision (normal or functional DVA) had a 90.9% (IC95% = [84.0; 97.8]) probability of preserving it at 6months and an 84.8% (IC95% = [76.2; 93.5]) probability at last follow-up. Patients with preoperative nonfunctional vision (nonfunctional DVA or blindness) had a 19.0% (IC95% = [2.3; 35.8]) probability of recovery of functional vision at 6months and a 23.8% (IC95% = [5.6; 42.0]) probability at last follow-up. Preoperative DVA was significantly associated with early postoperative DVA in univariate analyses (p = 0.04). Concerning the OcN, 65% of the patients experienced a postoperative dysfunction, and 78% of those cases recovered. Our study confirms EAC as a useful technical option for skull base meningiomas threatening the optic nerve, especially relevant for patients with preoperative functional vision, and supports early surgical management for these meningiomas.

How I do it: microsurgical clipping of carotid-ophthalmic aneurysms through minipterional approach with extradural resection of the anterior clinoid process

Background. In modern neurosurgery, preference is given to less invasive procedures. A classic example is switching from standard surgical approaches to keyhole approaches, in particular transition from pterional to minipterional approach. In turn, addition of extradural resection of the anterior clinoid process to the minipterional approach significantly expands the range of its indications.Method. The paper analyses the stages and main features of microsurgical clipping of carotid-ophthalmic aneurysms through the minipterional approach with extradural anterior clinoidectomy in patients operated in the Federal Centre of Neurosurgery (Tyumen, Russia) by professor Sufianov.Conclusion. The technique described in this research is a safe surgical approach, which demonstrates the efficacy of adding some skull base surgery elements to keyhole approaches. This type of craniotomy could become a method of choice for many neurosurgical conditions.

Complete Removal of Bilateral Clinoidal Meningiomas Through a Pterional Approach: 3-Dimensional Operative Video

Abstract Surgical removal of anterior clinoidal meningiomas remains a challenge because of its complicated relationship with surrounding vascular and neural structures. 1-3 This is a 39-yr-old female, with headaches, neurofibromatosis type 2, and history of 3 previous brain surgeries. The patient gave the consent to use the images and surgical video. In the imaging control, the growth of bilateral anterior clinoidal meningiomas was observed. A right pterional approach and extradural anterior clinoidectomy was performed, and a complete resection of bilateral clinoidal meningiomas was achieved obtaining a Simpson scale resection grade 1. The patient evolved without neurological deficits after the surgery, and the postoperative magnetic resonance imaging (MRI) evidenced a complete bilateral resection of the clinoidal meningiomas. Clinoidal meningiomas are the unique subset of tumors because of their close proximity to neurovascular structures and can be safely excised with minimal morbidity and mortality using microsurgical techniques. 3-5 In rare cases of bilateral anterior clinoidal meningiomas such as the case presented, we recommend detailed neuroimaging analysis and consider the possibility to resect both in a single approach.

Extradural anterior clinoidectomy in surgical management of clinoidal meningiomas

BackgroundDespite the recent advances in skull base surgery, microsurgical techniques, and neuroimaging, yet surgical resection of clinoidal meningiomas is still a major challenge. In this study, we present our institution experience in the surgical treatment of anterior clinoidal meningiomas highlighting the role of extradural anterior clinoidectomy in improving the visual outcome and the extent of tumor resection. This is a prospective observational study conducted on 33 consecutive patients with clinoidal meningiomas. The surgical approach utilized consisted of extradural anterior clinoidectomy, optic canal deroofing with falciform ligament opening in all patients. The primary outcome assessment was visual improvement and secondary outcomes were extent of tumor resection, recurrence, and postoperative complications.ResultsThe study included 5 males and 28 females with mean age 49.48 ± 11.41 years. Preoperative visual deficit was present in 30 (90.9%) patients. Optic canal involvement was present in 24 (72.7%) patients, ICA encasement was in 16 (48.5%), and cavernous sinus invasion in 8 (24.2%). Vision improved in 21 patients (70%), while 6 patients (20%) had stationary course and 1 patient (3%) suffered postoperative new visual deterioration. Gross total resection was achieved in 24 patients (72.7%). The main factors precluding total removal were cavernous sinus involvement and ICA encasement. Mortality rate was 6.1%; mean follow-up period was 27 ± 13 months.ConclusionsIn this series, the use of extradural anterior clinoidectomy provided a favorable visual outcome and improved the extent of resection in clinoidal meningioma patients.

Extradural anterior clinoidectomy through endoscopic transorbital approach: laboratory investigation for surgical perspective.

The endoscopic transorbital approach (eTOA) is a new mini-invasive procedure used to explore different areas of the skull base. Authors propose an extradural anterior clinoidectomy (AC) through this corridor, defining the anatomical landmarks of the anterior clinoid process (ACP) projection onto the posterior orbit wall and the technical feasibility of this approach. We describe the exposure of the opticocarotid region and the surgical freedom and the angles of attack obtained with this novel approach. Five cadaver heads underwent an eTOA at the Laboratory of Surgical Neuroanatomy of the University of Barcelona. A step-by-step description of the extradural endoscopic transorbital clinoidectomy was provided. A volumetric analysis of the morphometrics characteristics of the sphenoid wings was evaluated before and after dissection using CT scans. Pterional approach was performed to ascertain ACP removal. In all the specimens, it was possible to resect the ACP endo-orbitally aiming an optimal optic canal (OC) unroofing. The surface of the triangle corresponding to the ACP projection onto the posterior orbit wall was 0.42 ± 0.20 cm2. The drilled area to perform the extradural clinoidectomy via eTOA was 3.11 ± 2.27 cm2, and the volume of bone removal corresponding to the greater sphenoid wing (GSW) and lesser sphenoid wing (LSW) was 2.55 ± 1.41 and 0.26 ± 0.18 cm3 respectively. The area of surgical freedom provided by the eTOA was (3.11 ± 2.27cm2), and the angles of attack were 21.39 ± 9.13° in the horizontal axel and 30.63 ± 18.51° in the vertical. The described extradural anterior clinoidectomy by eTOA uses specific landmarks to localize the ACP on the posterior orbit wall. Resection of the ACP is a technically feasible approach, achieving the main goals of any clinoidectomy.

Direct Clipping of Paraclinoid Aneurysm in Conjunction with Extradural Anterior Clinoidectomy: Technical Nuance and Functional Outcome.

Objective Because of their anatomical features, treatment for paraclinoid aneurysms has remained to be challenging. Thus, the aim of this report is to prove the validity of our surgical method for unruptured paraclinoid aneurysms, together with surgical videos. Study Design Between August 2017 and November 2019, we were able to perform surgical clipping for 11 patients with unruptured paraclinoid aneurysm using a completely unified method. This study investigated the effect of surgery on multiple measures, including visual impairment, brain contusion, temporalis muscle atrophy, and multiple neurocognitive functions. Results Of the 67 unruptured aneurysms treated at our hospital, 17 were identified to be paraclinoid aneurysm, and 11 of them were treated by direct clipping using anterior clinoidectomy. Three were ophthalmic artery aneurysms, three were superior hypophyseal artery aneurysms, and five were anterior carotid wall aneurysms without branch projection. Only one patient had asymptomatic mild enlargement of the Marriott blind spots postoperatively. No brain contusion and temporalis muscle atrophy were observed in any cases. Only the Trail Making test (TMT) showed a significant worsening in the acute postoperative period: mean pre- and postoperative TMT scores were 59.1 ± 29.1 and 72.7 ± 37.3 for Part A ( p = 0.018) and 80.5 ± 35.5 and 93.8 ± 39.9 for Part B ( p = 0.030), respectively. However, it improved in the chronic phase. Conclusion We can conclude that our surgical method is safe and can be considered an acceptable treatment. Although surgical stress can cause temporary executive dysfunction shortly after surgery, this decline is temporary.

ANTERIOR CLINOIDECTOMY IN CLINOID SEGMENT INTERNAL CAROTID ANEURYSMS AND PARACLINOID MENINGIOMA: FROM ANATOMY TO NEUROSURGERY

Objectives: To assess the role of anatomy in the anterior clinoidectomy. Patients and methods: Retrospective study with ten patients who were surgically treated with the anterior clinoidectomy for the paraclinoid lesions at Viet-Duc Hospital from January 2020 to December 2020. Results: Mean age: 42.58 ± 12.49; sixty percents male and forty percents female. There was only one case that had pneumatization of the anterior clinoid process. On diagnosis, there were four cases with internal carotid aneurysms and six cases of paraclinoid meningioma. The extradural anterior clinoidectomy were in seven cases while the intradural way was in three cases. There was only one case of cerebrospinal fluid rhinorrhea as a complication. Conclusion: The anterior cliniodectomy was still challenging in neurosurgery. Understanding the anatomy of the anterior clinoid process was mandatory.

Role of Extradural Clinoidectomy and Optic Unroofing in Resection of an Anterior Clinoidal Meningioma with Encasement of the Internal Carotid Artery and Its Branches.

Anterior clinoidal meningiomas (ACMs) remain a major neurosurgical challenge. The skull base techniques, including extradural clinoidectomy and optic unroofing performed at the early stage of surgery, provide advantages for improving the extent of resection, and thereby enhancing overall outcome, and particularly visual function. Additionally, when the anterior clinoidal meningiomas encase neurovascular structures, particularly the supraclinoid internal carotid artery and its branches, this further increases morbidity and decreases the extent of resection. Although it might be possible to remove the tumor from the artery wall despite complete encasement or narrowing, the decision of whether the tumor can be safely separated from the arterial wall ultimately must be made intraoperatively. The patient is a 75-year-old woman with right-sided progressive vision loss. In the neurological examination, she only had light perception in the right eye without any visual acuity or peripheral loss in the left eye. MRI showed a homogeneously enhancing right-sided anterior clinoidal mass with encasing and narrowing of the supraclinoid internal carotid artery (ICA). Computed tomography (CT) angiography showed a mild narrowing of the right supraclinoid ICA with associated a 360-degree encasement. The decision was made to proceed using a pterional approach with extradural anterior clinoidectomy and optic unroofing. The surgery and postoperative course were uneventful. MRI confirmed gross total resection ( Figs. 1 and 2 ). The histopathology was a meningothelial meningioma, World Health Organization (WHO) grade I. The patient continues to do well without any recurrence and has shown improved vision at 15-month follow-up. This video demonstrates important steps of the microsurgical skull base techniques for resection of these challenging tumors. The link to the video can be found at https://youtu.be/vt3o1c2o8Z0

Impact of Anterior Clinoidectomy on Visual Function After Paraclinoid Carotid Artery Aneurysm Surgery: Power-Drill Versus No-Drill Technique

ABSTRACT BACKGROUND Few studies have attempted to make a direct comparison of the risk of visual impairment following extradural anterior clinoidectomy (EAC) with and without the use of a power drill. OBJECTIVE To evaluate postoperative visual outcomes between groups of patients with paraclinoid carotid artery aneurysms (PCAAs) who underwent surgical clipping with and without the use of a power drill during EAC. METHODS Between January 2010 and November 2019, 90 patients, 7 with ruptured and 83 with unruptured PCAAs, underwent clipping surgery at our hospital. The authors retrospectively analyzed postoperative visual complications from the medical records of these patients. RESULTS Among the 85 patients (excluding 3 patients with disturbance of consciousness caused by subarachnoid hemorrhage and 2 patients with preoperative visual disturbance) evaluated, EAC was conducted using a power drill in 64 patients and using a microrongeur in 21 patients. Permanent postoperative visual impairment developed in 14 (21.9%) patients in the drill group: 9 patients had ipsilateral lower nasal quadrant hemianopsia (ILNQH) and 5 patients had ipsilateral visual acuity reduction. Transient ILNQH developed in only 1 patient in the no-drill group. The incidence of permanent postoperative visual impairments was significantly lower in the no-drill group than in the drill group (P = .020). Seventeen (26.6%) patients developed transient oculomotor nerve palsy in the drill group, while no patients developed oculomotor nerve palsy in the no-drill group. CONCLUSION EAC using a microrongeur versus a power drill significantly improved visual outcomes after clipping surgery for PCAAs.

Cavernous Sinus Epidermoid Cyst Removal through a No-Keyhole Pterional Craniotomy: Operative Video and Technical Nuances.

Intracranial epidermoid cysts are considered benign tumors with good general prognosis. However, their radical removal may be associated with certain morbidity, especially when the capsule is attached to neurovascular structures. Epidermoid cysts located in the cavernous sinus are very rare. We present an operative video of a 22-year-old female patient, who suffered a right-sided headache for 5 years. The video demonstrates main steps and surgical nuances of resection of a right interdural cavernous sinus epidermoid cyst, measuring 22 × 19 × 21 mm (4.3 cc) ( Fig. 1A ). On initial physical examination, the patient had a right partial third nerve palsy (mild ptosis with minimal diplopia), without any other cranial nerve deficit. A right no-keyhole pterional craniotomy was performed, followed by extradural anterior clinoidectomy and peeling of the outer dural layer of the lateral wall of the cavernous sinus. The dura matter was also detached from the distal carotid dural ring, which was exposed by the clinoidectomy ( Fig. 2A ). This maneuver provided excellent exposure of the interdural epidermoid cyst, which severely compressed the oculomotor nerve against the posterior petroclinoid dural fold ( Fig. 2B ). Gross total resection of the epidermoid cyst was achieved ( Fig. 1B and C ). The patient developed a transient worsening of the third nerve palsy, which recovered completely 3 months after the surgery. Postoperative magnetic resonance imaging revealed no signs of residual tumor. The link to the video can be found at: https://youtu.be/pobhYb5ZNig .