Recovery of cranial nerve neuropathies after LINAC-based stereotactic radiosurgery for benign cavernous sinus meningioma.

PURPOSE: Cranial Nerve Neuropathies (CNNs) often accompany Cavernous Sinus Meningioma (CSM), for which Stereotactic Radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSR) are established treatments. This study assesses CNNs recovery in CSM patients treated with LINAC, offering insight into treatment effectiveness. METHODS: This study was conducted on 128 patients with CSM treated with LINAC-based SRS/FSR between 2005 and 2020 at a single institution. 46 patients presented with CNNs. The study analyzed patients' demographics, clinical parameters, SRS/FSR treatment characteristics, post-treatment CNNs recovery duration, status, and radiological control on their last follow-up. RESULTS: The median follow-up duration was 53.4 months. Patients were treated with SRS (n = 25) or FSR (n = 21). The mean pretreatment tumor volume was 9.5 cc decreasing to a mean end-of-follow-up tumor volume was 5.1 cc. Radiological tumor control was achieved in all cases. CNN recovery was observed in 80.4% of patients, with specific nerve recoveries documented as follows: extra-ocular nerves (43.2%), trigeminal nerve (32.4%), and optic nerve (10.8%). A higher CNNs recovery rate was associated with a smaller pre-treatment tumor volume (p < 0.001), and the median time-to-improvement was 3.7 months. Patients with tumor volumes exceeding 6.8 cc and those treated with FSR exhibited prolonged time-to-improvement (P < 0.03 and P < 0.04 respectively). CONCLUSIONS: This study suggests that SRS/FSR for CSM provides good and sustainable CNNs recovery outcomes with excellent long-term radiological control. A higher CNNs recovery rate was associated with a smaller pre-treatment tumor volume. while shorter time-to-improvement was identified in patients treated with SRS compared to FSR, particularly in those with small pre-treatment tumor volume.

Successful surgical treatment of oculomotor palsy due to schwannoma of the cavernous sinus in a 7-year-old girl: a case report.

Oculomotor nerve schwannoma in children not associated with neurofibromatosis is a rare disease, with 26 pediatric cases reported so far. There is no established treatment plan. A 7-year-old girl presented with oculomotor nerve palsy. Surgical reduction of the tumor combined with postoperative gamma knife surgery preserved the oculomotor nerve, improved oculomotor nerve function, and achieved tumor control during the observation period of 20 months. The combination of partial surgical resection and gamma knife surgery as a treatment strategy for oculomotor nerve schwannoma resulted in a good outcome.

A quantitative comparative surgical analysis of the endoscopic transorbital approach and frontotemporal-orbitozygomatic approach for extradural exposure of the cavernous sinus.

OBJECTIVE: Recently, the endoscopic superior eyelid transorbital approach (SETA) has emerged as a potential alternative to access the cavernous sinus (CS). Several previous studies have attempted to quantitatively compare the traditional open anterolateral skull base approaches with transorbital exposure; however, these comparisons have been limited to the area of exposure provided by the bone opening and trajectory, and fail to account for the main avenues of exposure provided by subsequent requisite surgical maneuvers. The authors quantitatively compare the surgical access provided by the frontotemporal-orbitozygomatic (FTOZ) approach and the SETA following applicable periclinoid surgical maneuvers, evaluate the surgical exposure of key structures in each, and discuss optimal approach selection. METHODS: SETA and FTOZ approaches were performed with subsequent applicable surgical maneuvers on 8 cadaveric heads. The lengths of exposure of cranial nerves (CNs) II-VI and the cavernous internal carotid artery; the areas of the space accessed within the supratrochlear, infratrochlear, and supramaxillary (anteromedial) triangles; the total area of exposure; and the angles of attack were measured and compared. RESULTS: Exposure of the extradural CS was comparable between approaches, whereas access was significantly greater in the FTOZ approach compared with the SETA. The lengths of extradural exposure of CN III, V1, V2, and V3 were comparable between approaches. The FTOZ approach provided marginally increased exposure of CNs IV (20.9 ± 2.36 mm vs 13.4 ± 3.97 mm, p = 0.023) and VI (14.1 ± 2.44 mm vs 9.22 ± 3.45 mm, p = 0.066). The FTOZ also provided significantly larger vertical (44.5° ± 6.15° vs 18.4° ± 1.65°, p = 0.002) and horizontal (41.5° ± 5.40° vs 15.3° ± 5.06°, p < 0.001) angles of attack, and thus significantly greater surgical freedom, and provided significantly greater access to the supratrochlear (p = 0.021) and infratrochlear (p = 0.007) triangles, and significantly greater exposure of the cavernous internal carotid artery (17.2 ± 1.70 mm vs 8.05 ± 2.37 mm, p = 0.001). Total area of exposure was also significantly larger in the FTOZ, which provided wide access to the lateral wall of the CS as well as the possibility for intradural access. CONCLUSIONS: This is the first study to quantitatively identify the relative advantages of the FTOZ and transorbital approaches at the target region following requisite surgical maneuvers. Understanding these data will aid in selecting an optimal approach and maneuver set based on target lesion size and location.

Comparison of the transarterial, transvenous, and superior ophthalmic vein approaches in the treatment of indirect carotid-cavernous fistulas.

OBJECTIVE: Indirect carotid-cavernous fistulas (CCFs) are abnormal arteriovenous shunting lesions with a highly variable clinical presentation that depends on the drainage pattern. Based on venous drainage, treatment can be either transarterial (TA) or transvenous (TV). The aim of this study was to compare the outcomes of indirect CCF embolization via the TA, TV, and direct superior ophthalmic vein (SOV) approaches. METHODS: The authors conducted a retrospective analysis of 74 patients admitted to their institution from 2010 to 2023 with the diagnosis of 77 indirect CCFs as confirmed on digital subtraction angiography. RESULTS: A total of 74 patients with 77 indirect CCFs were included in this study. Embolization was performed via the TA approach in 4 cases, the TV approach in 50 cases, and the SOV in 23 cases. At the end of the procedure, complete occlusion was achieved in 76 (98.7%) cases. The rate of complete occlusion at the end of the procedure and at last radiological follow-up was significantly higher in the SOV and TV cohorts than in the TA cohort. The rate of recurrence was highest in the TA cohort (25% for TA vs 5.3% for TV vs 0% for SOV, p = 0.68). CONCLUSIONS: The rate of immediate complete occlusion was higher in the TV and SOV cohorts than in the TA cohort while the rate of complete occlusion at final follow-up was highest in the SOV cohort. The SOV approach was significantly associated with higher rates of postoperative complications. Indirect CCFs require careful examination of the fistulous point and the venous drainage to provide the most effective patient-tailored approach.

Transorbital neuroendoscopic surgery for treatment of sphenoid wing meningiomas extending to the cavernous sinus: clinical implications and a technical illustration.

OBJECTIVE: The aim of this study was to evaluate the efficacy and safety of transorbital neuroendoscopic surgery (TONES) in the management of sphenoid wing meningiomas (SWMs) with cavernous sinus and orbital invasion. METHODS: The authors conducted a retrospective review of 32 patients with SWMs treated at Gazi University using TONES from October 2019 to May 2023. The study includes clinical applications to elucidate the endoscopic transorbital approach. Surgical techniques focused on safe subtotal resection, aiming to minimize residual tumor volume for subsequent radiosurgery. Data were collected on patient demographics, tumor characteristics, surgical procedures, complications, and postoperative outcomes, including radiological imaging and ophthalmological evaluations. RESULTS: Surgical dissections delineated a three-phase endoscopic transorbital approach: extraorbital, intraorbital, and intracranial. In the clinical application, gross-total resection was not achieved in any patient because of planned postoperative Gamma Knife radiosurgery. The mean follow-up period was 16.3 months. Of 30 patients with preoperative proptosis, 25 experienced postoperative improvement. No new-onset extraocular muscle paresis or visual loss occurred postoperatively. The average hospital stay was 1.15 days, with minimal complications and no significant morbidity or mortality. CONCLUSIONS: Total resection of SWMs invading the cavernous sinus and orbit is associated with substantial risks, particularly cranial nerve deficits. TONES offers a minimally invasive alternative, reducing morbidity compared with transcranial approaches, and represents a significant advancement in the surgical management of SWMs, especially those extending into the cavernous sinus and orbit. The approach provides a safe, effective, and patient-centric approach, prioritizing subtotal resection to minimize neurological deficits while preparing patients for adjunctive radiosurgery. This study positions TONES as a transformative surgical technique, aligning therapeutic efficacy with neurovascular preservation and postoperative recovery.

Circumferential exposure of the cavernous sinus and parasellar region through a combined open and endoscopic endonasal transcavernous approach, a morphometric study.

INTRODUCTION: Although recent trends currently favor the endoscopic endonasal transcavernous approach (EETA) over the pretemporal transcavernous approach (PTA) for certain cavernous sinus pathologies, dedicated assessment of the surgical exposure and maneuverability is wanting. Toward this aim, this morphometric study quantifies these variables within four cavernous sinus compartments by comparing the PTA, EETA, and a combined approach to achieve a circumferential dissection (EETA-PTA). MATERIAL: In five latex-injected specimens, exposure volumes of the EETA, PTA, and circumferential EETA-PTA approaches were quantified; the latter combined the most conservative options of both the endoscopic and open approaches. Two clinical cases illustrate the combined approach. RESULTS: EETA-PTA provided the largest volume of exposure (65.6% vs 35% PTA vs 44.6% EETA, P = 0.01) and eliminated the need to mobilize the ICA or cross cranial nerves. Although EETA and PTA approaches afforded comparable exposure volumes along the entire cavernous sinus (34.9 vs 44.6%), the EETA better exposed medial and inferior compartments (whereas the PTA exposed larger volumes in the lateral and superior compartments. The combined EETA-PTA yielded 66% of total cavernous sinus exposure volumes and eliminated the need to mobilize the ICA or cross cranial nerves. CONCLUSIONS: Our methodology aligns with strategies that use a modular concept to divide the skull base into compartments for maximal safe resection. Excluding soft tumors, the EETA is preferred for medial and inferior lesions and the PTA for superior and lateral lesions. A staged combined EETA-PTA may safely yield a 360-degree access for extensive multi-compartment lesions that span neurovascular structures within the cavernous sinus.

Endoscopic transcavernous approach for functional pituitary adenomas.

BACKGROUND: Invasion of the CS is one of the limiting factors for total resection for PitNet tumors with cure rates less than 30%. Extended approaches may be considered in selective and well-studied cases of secreting adenomas. METHOD: We describe the key steps of the endoscopic transcavernous approach for functional pituitary adenomas with a video illustration. The surgical anatomy is described along with the advantages and limitations of this approach. CONCLUSION: A detailed knowledge of CS anatomy and familiarity with this surgical approach acquired in the laboratory is essential. Proper instrumentation is critical to decrease the risks of vascular injury.

How I do it: Endoscopic endonasal resection of the medial wall of the cavernous sinus.

BACKGROUND: Resection of the medial wall of the cavernous sinus (MWCSR) is a growing surgical maneuver for the radical removal of pituitary adenomas. METHOD: We present a simple modification of the technique following the two dural layers of the floor of the sella turcica, allowing for early identification of the medial wall and simplifying dissection. We support this technique with an anatomical analysis on cadaveric specimens and clarifying dissection images. CONCLUSION: Recognition and dissection of the dural unfolding of the floor of the sella turcica are "key points" that lower the risk and facilitate the MWCSR.

Anterolateral surgical triangle of the cavernous sinus: a cadaveric study of neurosurgical importance.

BACKGROUND: The anterolateral triangle around the cavernous sinus is a surgical skull base triangle used as a neurosurgical landmark essential to skull-based surgeries. There are few reports of its measurements with little attention paid to anatomical variations. METHODOLOGY: A total of 15 adult human cadaveric skulls were dissected to expose the anterolateral triangle on both sides. The triangle was defined and measurements of the three borders were taken precisely and the area of each triangle was calculated using Heron's formula. RESULTS: On an average, the length of the anteromedial border is 11.4 (+ 2.2 mm); the length of the posteromedial border is 8.7 (+ 2.6 mm); the length of the lateral border is 13.06 (+ 2.6 mm) and the area of the anterolateral triangle is 48.05 (+ 17.5 mm2). CONCLUSION: Concise understanding of anterolateral triangle is essential to skull-based surgeries; comprehending its anatomy helps with better surgical planning and provides insight into local pathology.

Mullan's triangle or anteromedial triangle of the middle cranial fossa: a cadaveric study with its surgical importance.

BACKGROUND: Surgical approaches to the cavernous sinus (CS) and middle cranial fossa (MCF) can be challenging, particularly for young neurosurgeons. The anteromedial (Mullan's) triangle is a triangle by the side of the CS and constitutes part of the floor of the MCF. The contents include the sphenoid sinus, superior ophthalmic vein, and sixth cranial nerve. The literature contains very little research that has precisely defined and measured the anteromedial triangle while considering anatomical variances minimally. METHODOLOGY: The present study was conducted on the skulls of 25 adult human cadavers which were dissected to expose the anteromedial (Mullan's) triangle on both sides. After precisely defining the triangle on each side, measurements of the three borders were taken, and using Heron's formula, the area of each triangle was calculated. RESULTS: On average, the length of the medial border was 12.5 (+ 3.1 mm); the length of the lateral border was 9.9 (+ 3.1 mm); the length of the base was 10.75 (+ 2.4 mm) and the area of the anteromedial triangle was 43.9 (+ 15.06 mm2). CONCLUSION: Precise anatomical knowledge of the Mullan's triangle enables the treatment of disorders in often deformed anatomy or difficult-to-access structures. That is the reason it is important to gain a thorough understanding of the surgical anatomy and to adopt a safe procedure.

[Clinical observation of 7 cases of functional pituitary neuroendocrine tumor treated by endoscopic transnasal selective resection of the cavernous sinus medial wall].

The clinical data of 7 patients (3 males and 4 females) with functional pituitary neuroendocrine tumor treated by endoscopic transnasal resection of the cavernous sinus medial wall from May to October 2023 in the Department of Neurosurgery of the First Affiliated Hospital of University of Science and Technology of China were retrospectively analyzed. They ranged in age from 29 to 60, with an average age of 45. The clinical diagnosis was acromegaly in 5 cases and Cushing's disease in 2 cases. There were 1 cases of microadenoma and 6 cases of macroadenoma. Knosp grade: Grade 1 adenoma in 3 cases, grade 2 adenoma in 3 cases and grade 3A adenoma in 1 case. Intraoperative resection of cavernous sinus medial wall was performed on the side of tumor. Five cases were determined to be invaded by tumor, and 2 cases were uncertain. No internal carotid artery injury occurred in all patients. The average intraoperative blood loss was 156 ml, and no patient was transfused. Postoperative endocrine remission was found in 6 cases, and tumor cells were found in 6 cases by pathological examination of the medial wall of cavernous sinus. No serious complications occurred in all patients. For Knosp grade 1-3 functional pituitary neuroendocrine tumor surgery, if there is no clear false envelope or normal pituitary between the tumor and the cavernous sinus medial wall during the operation, the cavernous sinus medial wall should be actively removed to improve the postoperative endocrine remission rate.

Stereotactic radiosurgery for pituitary and cavernous sinus metastases.

PURPOSE: Metastases extending to the pituitary gland and cavernous sinus are extremely rare; however, advances in neuroimaging have increased the reported incidence. Stereotactic radiosurgery (SRS) affords the precise delivery of focused radiation to minimize adverse radiation effects. This study assessed the efficacy and safety of SRS in the treatment of pituitary and cavernous sinus metastases. METHODS: Analysis was performed on 23 patients with pituitary and cavernous sinus metastases who underwent treatment using SRS between 1996 and 2021. The cohort was categorized into 2 groups in terms of metastasis location: pituitary involvement (Group 1, n = 11) and cavernous sinus involvement (Group 2, n = 12). Overall survival, local tumor control, and distal tumor control rates were compared between the two groups using Kaplan-Meier analysis. RESULTS: The median age of the cohort was 52.2 years and the median tumor volume was 4.5 mL. Overall survival rates were as follows: 1 year (72.9%), 2 years (51.8%), and 3 years (45.3%). Local tumor control rates were as follows: 1 year (82.3%), 2 years (82.3%), and 3 years (65.9%). Visual deficit and hypopituitarism were the most common presentations in Group 1, whereas cranial nerve deficit was the most common presentation in Group 2. CONCLUSIONS: SRS appears to be a safe and effective therapy for the treatment of pituitary and cavernous sinus metastases. GKRS is a relatively simple procedure, which places minimal stress on the patient, thereby facilitating further anti-cancer treatment. Considering the limited survival duration in cases of metastasis, it is very likely that post-GKRS complications (e.g., new onset cranial nerve deficit and hypopituitarism) would not become an issue before patient passes away.

Efficacy and safety of cavernous sinus medial wall resection in pituitary adenoma surgery: a systematic review and a single-arm meta-analysis.

INTRODUCTION: Pituitary adenomas, benign tumors, can lower quality of life. Pituitary adenomas that invade the medial wall and cavernous sinus (CS) indicate tumor recurrence and partial surgical excision. Despite the cavernous sinus's complexity and risks, new research has improved the surgical procedure and made excision safer. This comprehensive review and single-arm meta-analysis evaluates endocrinological remission and resection rates in pituitary adenomas to determine the benefits and risks of MWCS resection. METHODS: Databases were systematically searched for studies documenting the resection of the medial wall of the cavernous sinus. The primary outcome was endocrinological remission in patients who underwent resection of the MWCS. RESULTS: Eight studies were included in the final analysis. The pooled proportion of endocrinological remission (ER) was 63.3%. The excision of MWCS pooled a gross total resection (GTR) proportion of 72.9%. Finally, ICA injury attained a pooled ratio of 0.5%, indicating minimal morbidity in the procedure. CONCLUSION: The cavernous sinus was ruled out, proving the MWCS excision is safe. Limiting population selection to Knosp 3A or lower enhanced GTR frequencies and lowered recurrence, according to subgroup analyses. This meta-analysis shows that MWCS resection can be a beneficial treatment option for pituitary tumors, when there is no macroscopic medial wall invasion and careful patient selection is done, especially for GH- and ACTH-producing tumors that can cause life-threatening metabolic changes.

A case report of pituitary neuroendocrine tumor manifesting as severe conjunctival chemosis.

BACKGROUND: Conjunctival chemosis (CC) is an extremely rare symptom of pituitary neuroendocrine tumor (PitNET). We report an extremely rare case of PitNET manifesting as severe CC. CASE PRESENTATION: A 48-year-old male was admitted to our hospital with severe CC, proptosis, and ptosis of the right eye. Magnetic resonance imaging demonstrated the tumor mass invading the cavernous sinus (CS) with cystic lesion. The patient underwent emergent endoscopic transsphenoidal surgery, and the pathological diagnosis was PitNET. CC of the right eye remarkably improved after the surgery. Glucocorticoid therapy was performed for right oculomotor nerve palsy, which rapidly improved. The postoperative course was uneventful and the patient was discharged from our hospital without hormone replacement. CONCLUSIONS: CC caused by CS invasion of PitNET can be cured by early surgical treatment. Therefore, PitNET is important to consider in the differential diagnosis of CC.

Video article: the subtemporal extradural approach to cavernous sinus tumour.

OBJECTIVE: Here we demonstrate via operative video the subtemporal extradural approach to a tumour in the cavernous sinus. METHODS: The extradural approach is performed here in a paediatric patient (a 15-year-old child) via a right extended pterional osteoplastic craniotomy with removal of the zygomatic arch. The operative microscope is introduced, and the dura is divided at the superior orbital fissure into endosteal and meningeal layers using a diamond knife. The middle cranial fossa floor is drilled flat to increase access, and the plane is further developed towards the cavernous sinus. The tumour is seen bulging from within the cavernous sinus, and the cavernous sinus is opened in the anteromedial triangle between cranial nerves Vi and Vii. After biopsy, the tumour is debulked with an ultrasonic aspirator. Doppler is used to identify the internal carotid artery and preserve it. The bone flap is replaced, and the wound is closed in layers in standard fashion. RESULTS: The patient recovered well and was discharged on post-operative day 3. Persistent sixth nerve palsy (present pre-operatively) was present; however, otherwise, there was good recovery from surgery. Good resection of tumour is demonstrated on post-operative MR imaging. CONCLUSIONS: This approach is uncommon but important as it enables extradural access to the cavernous sinus, minimising the complications associated with an intradural approach such as cortical injury. In this video, we also demonstrate the fundamental anatomy using annotation and cadaveric images to enhance understanding required for the neurosurgeon to successfully complete this approach. The patient consented to the procedure in the standard fashion.

The anterolateral triangle as window on the foramen lacerum from transorbital corridor: anatomical study and technical nuances.

OBJECTIVE: Neurosurgical indications for the superior eyelid transorbital endoscopic approach (SETOA) are rapidly expanding over the last years. Nevertheless, as any new technique, a detailed knowledge of the anatomy of the surgical target area, the operative corridor, and the specific surgical landmark from this different perspective is required for a safest and successful surgery. Therefore, the aim of this study is to provide, through anatomical dissections, a detailed investigation of the surgical anatomy revealed by SETOA via anterolateral triangle of the middle cranial fossa. We also sought to define the relevant surgical landmarks of this operative corridor. METHODS: Eight embalmed and injected adult cadaveric specimens (16 sides) underwent dissection and exposure of the cavernous sinus and middle cranial fossa via superior eyelid endoscopic transorbital approach. The anterolateral triangle was opened and its content exposed. An extended endoscopic endonasal trans-clival approach (EEEA) with exposure of the cavernous sinus content and skeletonization of the paraclival and parasellar segments of the internal carotid artery (ICA) was also performed, and the anterolateral triangle was exposed. Measurements of the surface area of this triangle from both surgical corridors were calculated in three head specimens using coordinates of its borders under image-guide navigation. RESULTS: The drilling of the anterolateral triangle via SETOA unfolds a space that can be divided by the course of the vidian nerve into two windows, a wider "supravidian" and a narrower "infravidian," which reveal different anatomical corridors: a "medial supravidian" and a "lateral supravidian," divided by the lacerum segment of the ICA, leading to the lower clivus, and to the medial aspect of the Meckel's cave and terminal part of the horizontal petrous ICA, respectively. The infravidian corridor leads medially into the sphenoid sinus. The arithmetic means of the accessible surface area of the anterolateral triangle were 45.48 ± 3.31 and 42.32 ± 2.17 mm2 through transorbital approach and endonasal approach, respectively. CONCLUSION: SETOA can be considered a minimally invasive route complementary to the extended endoscopic endonasal approach to the anteromedial aspect of the Meckel's cave and the foramen lacerum. The lateral loop of the trigeminal nerve represents a reliable surgical landmark to localize the lacerum segment of the ICA from this corridor. Nevertheless, as any new technique, a learning curve is needed, and the clinical feasibility should be proven.

Extradural disconnection of the cavernous sinus with preservation of the internal carotid artery: indication and technique.

BACKGROUND: Extradural disconnection of the cavernous sinus (CS) with preservation of the internal carotid artery (ICA) is indicated for aggressive and recurrent tumors, in patients presenting loss of oculomotor function and non-functional circle of Willis. METHOD: Extradural resection of the anterior clinoid process disconnects the CS anteriorly. The ICA is dissected in the foramen lacerum via extradural subtemporal approach. The intracavernous tumor is split and removed following the ICA. Bleeding control of the inferior and superior petrosal and intercavernous sinuses completes posterior CS disconnection. CONCLUSION: This technique can be proposed for recurrent CS tumors and need of ICA preservation.

The "candy wrapper" of the pituitary gland: a road map to the parasellar ligaments and the medial wall of the cavernous sinus.

PURPOSE: The anatomy of the medial wall of the cavernous sinus (MWCS) and parasellar ligaments (PLs) has acquired increasing importance in endoscopic endonasal (EE) surgery of the cavernous sinus (CS), including resection of the MWCS in functioning pituitary adenomas (FPAs). Although anatomical studies have been published, it represents a debated topic due to their complex morphology. The aim is to offer a description of the PLs that originate from the MWCS and reach the lateral wall of the cavernous sinus (LWCS), proposing the "candy wrapper" model. The relationships between the neurovascular structures and histomorphological aspects were investigated. METHODS: Forty-two CSs from twenty-one human heads were studied. Eleven specimens were used for EE dissection; five underwent a microscopic dissection. Five specimens were used for histomorphological analysis. RESULTS: Two groups of PLs with a fan-shaped appearance were encountered. The anterior group included the periosteal ligament (55% sides) and the carotico-clinoid complex (100% sides), formed by the anterior horizontal and the carotico-clinoid ligaments. The posterior group was formed by the posterior horizontal (78% sides), and the inferior hypophyseal ligament (34% sides). The periosteal ligament originated inferiorly from the MWCS, reaching the periosteal dura. The anterior horizontal ligament was divided in a superior and inferior branch. The superior one continued as the carotid-oculomotor membrane, and the inferior branch reached the CN VI. The carotico-clinoid ligament between the middle and anterior clinoid was ossified in 3 sides. The posterior horizontal ligament was related to the posterior genu and ended at the LWCS. The inferior hypophyseal ligament followed the homonym artery. The ligaments related to the ICA form part of the adventitia. CONCLUSION: The "candy wrapper" model adds further details to the previous descriptions of the PLs. Understanding this complex anatomy is essential for safe CS surgery, including MWCS resection for FPAs.

How we do it? Performing a protective superficial temporal artery-middle cerebral artery bypass with endoscopic transnasal cavernous sinus lesion operation.

BACKGROUND: To describe the concept of a protective superficial temporal artery-middle cerebral artery (STA-MCA) bypass performed prior to endoscopic transnasal cavernous sinus (CS) lesion resection in order to reduce the risk of perioperative cerebral ischemia due to internal carotid artery (ICA) vasospasm, occlusion, and even injury. METHOD: We illustrated the procedure of a 14-year-old female accepting a protective STA-MCA bypass with endoscopic transnasal CS lesion resection. CONCLUSION: A protective bypass may be a prophylactic strategy in selected endoscopic transnasal CS surgery cases, particularly where the diagnosis is uncertain, or the risk of ICA injury or occlusion is high.

Cavernous sinus haemangioma masquerading as a pituitary macroadenoma: how the unexpected lurks in neurosurgery.

Cavernous sinus haemangiomas are neoplastic lesions notoriously difficult to diagnose and excise. We present a case of a lesion that was clinically, biochemically, and radiologically consistent to a giant pituitary macroadenoma and discuss the unexpected near intra-operative exsanguination which enabled a pathognomonic diagnosis of a much rarer lesion to be made. This highlights the sinister nature of such a lesion, and its potential impact on patient care if partially excised, and that despite our advances in neurosurgical diagnostics the unexpected is to be expected.