360 Degrees Endoscopic Access to and Through the Orbit.

The treatment of pathologies located within and surrounding the orbit poses considerable surgical challenges, due to the intricate presence of critical neurovascular structures in such deep, confined spaces. Historically, transcranial and craniofacial approaches have been widely employed to deal with orbital pathologies. However, recent decades have witnessed the emergence of minimally invasive techniques aimed at reducing morbidity. Among these techniques are the endoscopic endonasal approach and the subsequently developed endoscopic transorbital approach (ETOA), encompassing both endonasal and transpalpebral approaches. These innovative methods not only facilitate the management of intraorbital lesions but also offer access to deep-seated lesions within the anterior, middle, and posterior cranial fossa via specific transorbital and endonasal corridors. Contemporary research indicates that ETOAs have demonstrated exceptional outcomes in terms of morbidity rates, cosmetic results, and complication rates. This study aims to provide a comprehensive description of endoscopic-assisted techniques that enable a 360° access to the orbit and its surrounding regions. The investigation will delve into indications, advantages, and limitations associated with different approaches, while also drawing comparisons between endoscopic approaches and traditional microsurgical transcranial approaches.

Surgery versus endovascular treatment for spinal dural arteriovenous fistulas: a multicenter experience and systematic literature review.

Surgery and endovascular therapy are the primary treatment options for spinal dural arteriovenous fistula (SDAVF). Due to the absence of a consensus regarding which therapy yields a superior outcome, we conducted a comparative analysis of the surgical and endovascular treatment of SDAVF through a multicenter case series and a systematic literature review. Patients with SDAVF, surgically or endovascularly treated at four neurosurgical centers from January 2001 to December 2021, were included in this study. Level of SDAVF, primary treatment modality, baseline and post-procedural neurological status were collected. The primary outcomes were failure, complication rates, and a newly introduced parameter named as therapeutic delay. A systematic review of the literature was performed according to PRISMA-P guidelines. The systematic review identified 511 papers, of which 18 were eligible for analysis, for a total of 814 patients, predominantly male (72%) with a median age of 61 and mainly thoracic SDAVFs (65%). The failure rate was significantly higher for endovascular therapy (20%) compared to surgery (4%) (p < 0.01). Neurological complications were generally rare, with similar rates among the two groups (endovascular 2.9%; surgery 2.6%). Endovascular treatment showed a statistically significantly higher rate of persistent neurological complications than surgical treatment (2.9% versus 0.2%; p < 0.01). Both treatments showed similar rates of clinical improvement based on Aminoff Logue scale score. The multicenter, retrospective study involved 131 patients. The thoracic region was the most frequent location (58%), followed by lumbar (37%). Paraparesis (45%) and back pain (41%) were the most common presenting symptoms, followed by bladder dysfunction (34%) and sensory disturbances (21%). The mean clinical follow-up was 21 months, with all patients followed for at least 12 months. No statistically significant differences were found in demographic and clinical data, lesion characteristics, or outcomes between the two treatment groups. Median pre-treatment Aminoff-Logue score was 2.6, decreasing to 1.4 post-treatment with both treatments. The mean therapeutic delay for surgery and endovascular treatment showed no statistically significant difference. Surgical treatment demonstrated significantly lower failure rates (5% vs. 46%, p < 0.01). In the surgical group, 2 transient neurological (1 epidural hematoma, 1 CSF leak) and 3 non-neurological (3 wound infections) complications were recorded; while 2 permanent neurological (spinal infarcts), and 5 non-neurological (inguinal hematomas) were reported in the endovascular group. According to the literature review and this multicenter clinical series, surgical treatment has a significantly lower failure rate than endovascular treatment. Although the two treatments have similar complication rates, endovascular treatment seems to have a higher rate of persistent neurological complications.

360° around the orbit: key surgical anatomy of the microsurgical and endoscopic cranio-orbital and orbitocranial approaches.

OBJECTIVE: Several pathologies either invade or arise within the orbit. These include meningiomas, schwannomas, and cavernous hemangiomas among others. Although several studies describing various approaches to the orbit are available, no study describes all cranio-orbital and orbitocranial approaches with clear, surgically oriented anatomical descriptions. As such, this study aimed to provide a comprehensive guide to the microsurgical and endoscopic approaches to and through the orbit. METHODS: Six formalin-fixed, latex-injected cadaveric head specimens were dissected in the surgical anatomy laboratory at the authors' institution. In each specimen, the following approaches were modularly performed: endoscopic transorbital approaches (ETOAs), including a lateral transorbital approach and a superior eyelid crease approach; endoscopic endonasal approaches (EEAs), including those to the medial orbit and optic canal; and transcranial approaches, including a supraorbital approach, a fronto-orbital approach, and a 3-piece orbito-zygomatic approach. Each pertinent step was 3D photograph-documented with macroscopic and endoscopic techniques as previously described. RESULTS: Endoscopic endonasal approaches to the orbit afforded excellent access to the medial orbit and medial optic canal. Regarding ETOAs, the lateral transorbital approach afforded excellent access to the floor of the middle fossa and, once the lateral orbital rim was removed, the cavernous sinus could be dissected and the petrous apex drilled. The superior eyelid approach provides excellent access to the anterior cranial fossa just superior to the orbit, as well as the dura of the lesser wing of the sphenoid. Craniotomy-based approaches provided excellent access to the anterior and middle cranial fossa and the cavernous sinus, except the supraorbital approach had limited access to the middle fossa. CONCLUSIONS: This study outlines the essential surgical steps for major cranio-orbital and orbitocranial approaches. Endoscopic endonasal approaches offer direct medial access, potentially providing bilateral exposure to optic canals. ETOAs serve as both orbital access and as a corridor to surrounding regions. Cranio-orbital approaches follow a lateral-to-medial, superior-to-inferior trajectory, progressively allowing removal of protective bony structures for proportional orbit access.

The Current Diagnostic Performance of MRI-Based Radiomics for Glioma Grading: A Meta-Analysis.

BACKGROUND: Multiple radiomics models have been proposed for grading glioma using different algorithms, features, and sequences of magnetic resonance imaging. The research seeks to assess the present overall performance of radiomics for grading glioma. METHODS: A systematic literature review of the databases Ovid MEDLINE PubMed, and Ovid EMBASE for publications published on radiomics for glioma grading between 2012 and 2023 was performed. The systematic review was carried out following the criteria of Preferred Reporting Items for Systematic Reviews and Meta-Analysis. RESULTS: In the meta-analysis, a total of 7654 patients from 40 articles, were assessed. R-package mada was used for modeling the joint estimates of specificity (SPE) and sensitivity (SEN). Pooled event rates across studies were performed with a random-effects meta-analysis. The heterogeneity of SPE and SEN were based on the χ2 test. Overall values for SPE and SEN in the differentiation between high-grade gliomas (HGGs) and low-grade gliomas (LGGs) were 84% and 91%, respectively. With regards to the discrimination between World Health Organization (WHO) grade 4 and WHO grade 3, the overall SPE was 81% and the SEN was 89%. The modern non-linear classifiers showed a better trend, whereas textural features tend to be the best-performing (29%) and the most used. CONCLUSIONS: Our findings confirm that present radiomics' diagnostic performance for glioma grading is superior in terms of SEN and SPE for the HGGs vs. LGGs discrimination task when compared to the WHO grade 4 vs. 3 task.

Advancing Craniopharyngioma Management: A Systematic Review of Current Targeted Therapies and Future Perspectives.

Craniopharyngiomas present unique challenges in surgical management due to their proximity to critical neurovascular structures. This systematic review investigates genetic and immunological markers as potential targets for therapy in craniopharyngiomas, assessing their involvement in tumorigenesis, and their influence on prognosis and treatment strategies. The systematic review adhered to PRISMA guidelines, with a thorough literature search conducted on PubMed, Ovid MED-LINE, and Ovid EMBASE. Employing MeSH terms and Boolean operators, the search focused on craniopharyngiomas, targeted or molecular therapy, and clinical outcomes or adverse events. Inclusion criteria encompassed English language studies, clinical trials (randomized or non-randomized), and investigations into adamantinomatous or papillary craniopharyngiomas. Targeted therapies, either standalone or combined with chemotherapy and/or radiotherapy, were examined if they included clinical outcomes or adverse event analysis. Primary outcomes assessed disease response through follow-up MRI scans, categorizing responses as follows: complete response (CR), near-complete response (NCR), partial response, and stable or progressive disease based on lesion regression percentages. Secondary outcomes included treatment type and duration, as well as adverse events. A total of 891 papers were initially identified, of which 26 studies spanning from 2000 to 2023 were finally included in the review. Two tables highlighted adamantinomatous and papillary craniopharyngiomas, encompassing 7 and 19 studies, respectively. For adamantinomatous craniopharyngiomas, Interferon-2α was the predominant targeted therapy (29%), whereas dabrafenib took precedence (70%) for papillary craniopharyngiomas. Treatment durations varied, ranging from 1.7 to 28 months. Positive responses, including CR or NCR, were observed in both types of craniopharyngiomas (29% CR for adamantinomatous; 32% CR for papillary). Adverse events, such as constitutional symptoms and skin changes, were reported, emphasizing the need for vigilant monitoring and personalized management to enhance treatment tolerability. Overall, the data highlighted a diverse landscape of targeted therapies with encouraging responses and manageable adverse events, underscoring the importance of ongoing research and individualized patient care in the exploration of treatment options for craniopharyngiomas. In the realm of targeted therapies for craniopharyngiomas, tocilizumab and dabrafenib emerged as prominent choices for adamantinomatous and papillary cases, respectively. While adverse events were common, their manageable nature underscored the importance of vigilant monitoring and personalized management. Acknowledging limitations, future research should prioritize larger, well-designed clinical trials and standardized treatment protocols to enhance our understanding of the impact of targeted therapies on craniopharyngioma patients.

A Systematic Review of the Metabolism of High-Grade Gliomas: Current Targeted Therapies and Future Perspectives.

High-grade glial tumors (HGGs) exhibit aggressive growth patterns and high recurrence rates. The prevailing treatment approach comprises radiation therapy (RT), chemotherapy (CMT), and surgical resection. Despite the progress made in traditional treatments, the outlook for patients with HGGs remains bleak. Tumor metabolism is emerging as a potential target for glioma therapies, a promising approach that harnesses the metabolism to target tumor cells. However, the efficacy of therapies targeting the metabolism of HGGs remains unclear, compelling a comprehensive review. This study aimed to assess the outcome of present trials on HGG therapies targeting metabolism. A comprehensive search of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted until November 2023. The search method used pertinent Medical Subject Heading (MeSH) terminologies and keywords referring to "high-grade gliomas", "metabolism", "target therapies", "monoclonal antibodies", "overall survival", and "progression-free survival". The review analyzed studies that focused on therapies targeting the metabolism of HGGs in human subjects. These studies included both randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs). Out of 284 articles identified, 23 trials met the inclusion criteria and were thoroughly analyzed. Phase II trials were the most numerous (62%). Targeted metabolic therapies were predominantly used for recurrent HGGs (67%). The most common targeted pathways were the vascular endothelial growth factor (VEGF, 43%), the human epidermal growth factor receptor (HER, 22%), the platelet-derived growth factor (PDGF, 17%), and the mammalian target of rapamycin (mTOR, 17%). In 39% of studies, the subject treatment was combined with CMT (22%), RT (4%), or both (13%). The median OS widely ranged from 4 to 26.3 months, while the median PFS ranged from 1.5 to 13 months. This systematic literature review offers a thorough exploration of the present state of metabolic therapies for HGGs. The multitude of targeted pathways underscores the intricate nature of addressing the metabolic aspects of these tumors. Despite existing challenges, these findings provide valuable insights, guiding future research endeavors. The results serve as a foundation for refining treatment strategies and enhancing patient outcomes within the complex landscape of HGGs.

COVID-19-associated Guillain-Barré syndrome in the early pandemic experience in Lombardia (Italy).

OBJECTIVE: To estimate the incidence and describe clinical characteristics and outcome of GBS in COVID-19 patients (COVID19-GBS) in one of the most hit regions during the first pandemic wave, Lombardia. METHODS: Adult patients admitted to 20 Neurological Units between 1/3-30/4/2020 with COVID19-GBS were included as part of a multi-center study organized by the Italian society of Hospital Neuroscience (SNO). RESULTS: Thirty-eight COVID19-GBS patients had a mean age of 60.7 years and male frequency of 86.8%. CSF albuminocytological dissociation was detected in 71.4%, and PCR for SARS-CoV-2 was negative in 19 tested patients. Based on neurophysiology, 81.8% of patients had a diagnosis of AIDP, 12.1% of AMSAN, and 6.1% of AMAN. The course was favorable in 76.3% of patients, stable in 10.5%, while 13.2% worsened, of which 3 died. The estimated occurrence rate in Lombardia ranges from 0.5 to 0.05 GBS cases per 1000 COVID-19 infections depending on whether you consider positive cases or estimated seropositive cases. When we compared GBS cases with the pre-pandemic period, we found a reduction of cases from 165 to 135 cases in the 2-month study period in Lombardia. CONCLUSIONS: We detected an increased incidence of GBS in COVID-19 patients which can reflect a higher risk of GBS in COVID-19 patients and a reduction of GBS events during the pandemic period possibly due to a lower spread of more common respiratory infectious diseases determined by an increased use of preventive measures.

Microsurgical transcranial approaches to the posterior surface of petrosal portion of the temporal bone: quantitative analysis of surgical volumes and exposed areas.

Different microsurgical transcranial approaches (MTAs) have been described to expose the posterior surface of the petrous bone (PPB). A quantitative, anatomical comparison of the most used MTAs, for specific areas of the PPB, is not available. Anatomical dissections were performed on five formalin-fixed, latex-injected cadaver heads (10 sides). Six MTAs were analyzed: Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), retrolabyrinthine approach (RLA), translabyrinthine approach (TLA), and transcochlear approach (TCA). Surgical volumes and exposed areas of each approach were quantified with a dedicated neuronavigation system (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada) and adjuvant software (ITK-SNAP and Autodesk Meshmixer 3.5). Areas and volumes were compared using linear mixed models. TCA provided the best exposure of Trautmann's triangle and the retromeatal, suprameatal, meatal, and premeatal regions. RSAs provided the best exposure of the inframeatal region, with RSAS gaining significant exposure of the suprameatal region. KWA had the highest surgical volume, and RLA the lowest. Transpetrosal approaches offer the widest exposure of PPB proportionally to their invasiveness. Retrosigmoid approaches, which get to the studied region through a postero-lateral path, are paramount for the exposure of the inframeatal and suprameatal region and, given the adequate exposure of the remaining PPB, represent an effective approach for the cerebellopontine angle (CPA). These anatomical findings must be considered with approach-related morbidity and the pathological features in order to choose the most appropriate approach in clinical practice.

Combined endoscopic endonasal and sublabial transmaxillary approaches for resection of intracranially extended juvenile nasopharyngeal angiofibroma.

BACKGROUND: Juvenile nasopharyngeal angiofibromas (JNAs) are rare, benign, and locally invasive nasopharyngeal tumors. Endoscopic endonasal resection is effective, non-invasive, with low complication rates. Until recently, endoscopic resection was not suitable for intracranially invasive tumors. PURPOSE/METHOD: We describe resection steps of an intracranially extending JNA with a combined endoscopic endonasal and endoscopic-assisted sublabial transmaxillary approaches. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video. CONCLUSION: Surgical excision of JNAs by a combined endoscopic endonasal and sublabial transmaxillary approaches represents a safe and effective treatment for selected intracranially invasive JNA.

Endoscopic endonasal surgical anatomy of the optic canal: key anatomical relationships between the optic nerve and ophthalmic artery.

PURPOSE: A detailed understanding of the neurovascular relationships between the optic nerve (ON) and the ophthalmic artery (OA) in the optic canal (OC) is paramount for safe surgery. We focused on the neurovascular anatomy of this area from both an endoscopic endonasal and transcranial trajectories to compare the surgical exposures and perspectives offered by these different views and provide recommendations to increase the intraoperative safety. METHODS: Twenty sides of ten formalin-fixed, latex-injected head specimens were utilized. The surgical anatomy and anatomical relationships of the OA in relationship to the ON along their intracranial and intracanalicular segments was studied from endoscopic endonasal and transcranial perspectives. RESULTS: Three types of OA-ON relationships at the origin of the OA were identified: inferomedial (type 1, 35%), inferior (type 2, 55%), and inferolateral (type 3, 10%). The endoscopic endonasal trajectory offers an inferomedial perspective of the ON-OA neurovascular complex, in which the OA, especially when located inferomedially, is first encountered. When comparing with the transcranial view, all OA were covered by the nerve, type 1 was located below the medial third, type 2 below the middle third, and type 3 below the lateral third of the OC. The mean extension of the intracanalicular portion of both OA and ON was 8.9 mm, while the intracranial portion of the OA and ON were 9.3 mm and 12.4 mm, respectively. The OA, endoscopically, is located within the inferior half of the OC, and occupies 39%, 43%, and 42% of the OC height at its origin, mid, and end points, respectively. The mean distance between the superior margin of the OC at its origin and superior margin of the OA is 1.4 mm. CONCLUSIONS: Detailed anatomical understanding of the OC, and the ON and OA at their intracranial and intracanalicular segments is paramount to safe surgery. When opening the OC dura endoscopically, our results suggest that a medial incision along the superior third of the OC with a proximal to distal direction is recommended to avoid injury of the OA.

Treatment strategy for vertebral metastases from anal squamous cell carcinoma: a comprehensive literature review and case report.

Purpose/aim of the study: Purpose/aim of the study:Central nervous system (CNS), skull, and vertebral metastases from anal squamous cell carcinoma (SCC) are an exceedingly rare entity. We report the first case of multiple vertebral metastases from a primary anal SCC with the aim of define a target therapeutic strategy.Case presentation: We present the case of a 68-year-old male admitted to our hospital for acute exacerbation chronic low back pain and left L2 radiculopathy. His medical history included the diagnosis of a human papilloma virus related, moderately differentiated anal SCC (cT3N0M0-stage IIB), treated with standard chemoradiotherapy regimen two years earlier. Spinal magnetic resonance imaging revealed an isolated solid lesion of the L2 vertebral body. After the surgical removal, histopathological examination confirmed the diagnosis of moderately differentiated SCC. At 1-month radiological follow-up, two new lesions at the level of T7 to T11 were identified. Additional chemotherapy and radiotherapy for metastatic localization of L2, T7, and T11 were administered. Two-year follow-up demonstrated a radiologically and clinically well-controlled disease. To supplement our case, a systematic literature review on the CNS, skull, and vertebral metastases and their treatments has been performed.Conclusion: Despite several proposed guidelines for the management of vertebral metastases, at present, a universally accepted treatment strategy for vertebral metastases from anal SCC has not been defined. Based on our clinical experience and literature review, in case of vertebral metastases from anal SCC, a prompt and aggressive, local and systemic, and multimodal treatment of the vertebral lesions may be paramount to improve the patient outcomes.

Non-surgical management of chronic subdural hematoma: insights and future perspectives from an international survey including neurosurgeons from 90 countries worldwide.

BACKGROUND: Chronic subdural hematoma (cSDH) is one of the most common neurosurgical conditions. Although surgical evacuation is still the gold standard for treatment, recent advances have led to the development of other management strategies, such as medical therapies and endovascular middle meningeal artery (MMA) embolization. Through this international survey, we investigated the global trends in cSDH management, focusing on medical and endovascular treatments. DESIGN AND PARTICIPANTS: A 14-question, web-based, anonymous survey was distributed to neurosurgeons worldwide. RESULTS: Most responders do not perform MMA embolization (69.5%) unless for specific indications (29.6%). These indications include residual cSDH after surgical evacuation (58.9%) or cSDH in patients on antiplatelet medications to avoid surgical evacuation (44.8%). Survey participants from teaching versus non-teaching hospitals (p = 0.002), public versus private hospitals (p = 0.022), and Europe versus other continents (p < 0.001) are the most users of MMA embolization. A large number of participants (51%) declare they use a conservative/medical approach, mainly to avoid surgery in patients with small cSDH (74.8%). CONCLUSIONS: This survey highlights the current trends of cSDH management, focusing on conservative and MMA embolization treatment strategies. Most responders prefer a conservative approach for patients with small cSDHs not requiring surgical evacuation. However, in higher-risk scenarios such as residual hematomas after surgery or patients on antiplatelet medications, MMA embolization is regarded as a reasonable option by participants. Future studies should clarify the indications of MMA embolization, including appropriate patient selection and efficacy as a stand-alone procedure.

Glioblastoma Immunotherapy: A Systematic Review of the Present Strategies and Prospects for Advancements.

Glioblastoma (GBM) is characterized by aggressive growth and high rates of recurrence. Despite the advancements in conventional therapies, the prognosis for GBM patients remains poor. Immunotherapy has recently emerged as a potential treatment option. The aim of this systematic review is to assess the current strategies and future perspectives of the GBM immunotherapy strategies. A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to 3 September 2023. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to "glioblastomas," "immunotherapies," and "treatment." The studies included in this review consist of randomized controlled trials, non-randomized controlled trials, and cohort studies reporting on the use of immunotherapies for the treatment of gliomas in human subjects. A total of 1588 papers are initially identified. Eligibility is confirmed for 752 articles, while 655 are excluded for various reasons, including irrelevance to the research topic (627), insufficient method and results details (12), and being case-series or cohort studies (22), systematic literature reviews, or meta-analyses (3). All the studies within the systematic review were clinical trials spanning from 1995 to 2023, involving 6383 patients. Neuro-oncology published the most glioma immunotherapy-related clinical trials (15/97, 16%). Most studies were released between 2018 and 2022, averaging nine publications annually during this period. Adoptive cellular transfer chimeric antigen receptor (CAR) T cells were the primary focus in 11% of the studies, with immune checkpoint inhibitors (ICIs), oncolytic viruses (OVs), and cancer vaccines (CVs) comprising 26%, 12%, and 51%, respectively. Phase-I trials constituted the majority at 51%, while phase-III trials were only 7% of the total. Among these trials, 60% were single arm, 39% double arm, and one multi-arm. Immunotherapies were predominantly employed for recurrent GBM (55%). The review also revealed ongoing clinical trials, including 9 on ICIs, 7 on CVs, 10 on OVs, and 8 on CAR T cells, totaling 34 trials, with phase-I trials representing the majority at 53%, and only one in phase III. Overcoming immunotolerance, stimulating robust tumor antigen responses, and countering immunosuppressive microenvironment mechanisms are critical for curative GBM immunotherapy. Immune checkpoint inhibitors, such as PD-1 and CTLA-4 inhibitors, show promise, with the ongoing research aiming to enhance their effectiveness. Personalized cancer vaccines, especially targeting neoantigens, offer substantial potential. Oncolytic viruses exhibited dual mechanisms and a breakthrough status in the clinical trials. CAR T-cell therapy, engineered for specific antigen targeting, yields encouraging results, particularly against IL13 Rα2 and EGFRvIII. The development of second-generation CAR T cells with improved specificity exemplifies their adaptability.

Principles and strategies for step-by-step AVM excision.

Arteriovenous malformations (AVMs) are some of the most challenging surgical entities. Like any challenging surgical procedure, AVM surgery is a series of basic but fundamental steps, each with its own nuances. Despite a myriad of published material regarding AVMs, there are few succinct illustrated summaries of these steps with an accompanying elucidation of the most common pitfalls. This paper provides a step-by-step description and illustration of the basic surgical principles of AVM microsurgical resection, focusing on the main key points and addressing the critical issues that surround this surgery. Deep anatomical knowledge and presurgical planning of these basic steps, combined with good contingency management skills, are paramount for an effective and safe AVM surgery.

How I do it: resection of spinal cord cavernous malformation.

BACKGROUND: Spinal cord cavernous malformations (CMs) account for 5 to 12% of all spinal vascular malformations. Surgical removal is indicated in symptomatic patients, especially if the CM comes close to the dorsal or lateral surface of the spinal cord. Spinal cord CMs pose critical challenges for the potential of severe disabling complications. METHOD: We described the step-by-step surgical principles of spinal cord CM microsurgical resection. The main surgical steps are also illustrated in an accompanying operative video. CONCLUSION: Pre-surgical planning of the basic steps and good contingency management skills are paramount for an effective and safe spinal cord CM excision.

The precuneal interhemispheric, trans-tentorial corridor to the pineal region and brainstem, surgical anatomy, and case illustration.

BACKGROUND: The pineal region and dorsal midbrain are among the most challenging surgical targets. To approach lesions in this region that harbor a superior to inferior long axis, we describe the basic steps of the precuneal, interhemispheric, trans-tentorial approach and illustrate anatomical landmarks of this established, but not so popular, surgical trajectory. METHOD: To study the anatomical landmarks and safety of this approach, the neurovascular anatomy was studied on 22 sides of 11 formalin-fixed latex-injected anatomical specimens. A step-by-step dissection of the precuneal interhemispheric trans-tentorial approach and study of the key anatomical landmarks was performed. An illustrative clinical case of a pontomesencephalic cavernous malformation (CM) resected through this approach is also detailed. RESULTS: The mean distance from the transverse sinus to the most posterior cortical vein draining into the superior sagittal sinus was 6.4 cm. The mean distance from the calcarine sulcus to the most posterior cortical vein was 5.3 cm. Key steps of the dissection are as follows: craniotomy exposing the posterior aspect of the superior sagittal sinus (SSS), durotomy and gentle retraction of the SSS edge, dissection of the interhemispheric fissure, linear incision of the tentorium that extends anteriorly to the incisura and lateral reflection of the tentorium, and arachnoidal dissection and exposure of the cerebellomesencephalic fissure. CONCLUSION: The precuneal, interhemispheric, trans-tentorial approach affords excellent access to the falcotentorial junction, splenium, pineal region, quadrigeminal cistern, and dorsal pons once the cerebellomesencephalic fissure has been dissected.

Endoscopic endonasal surgical anatomy through the prechiasmatic sulcus: the key window to suprachiasmatic and infrachiasmatic corridors.

BACKGROUND: Classically, the transtuberculum and transplanum approaches have been utilized to reach the suprachiasmatic and infrachiasmatic corridors. The aim of this study was to provide a better understanding of the key endoscopic endonasal anatomy of the suprachiasmatic and infrachiasmatic corridors provided through selective removal of the prechiasmatic sulcus (SRPS). METHOD: A SRPS was performed in 16 sides of 8 alcohol-fixed head specimens. Twenty anatomical measurements were collected on the suprachiasmatic and infrachiasmatic corridors. The transplanum and transtuberculum approaches were also performed. RESULTS: In the suprachiasmatic corridor, the SRPS exposed the anterior communicating artery (AComm) and the post-communicating segment of the anterior cerebral arteries in all the cases, while the pre-communicating segment of the anterior cerebral arteries, recurrent arteries of Heubner, and fronto-orbital arteries were visualized in 75% (12/16), 31% (5/16), and 69% (11/16) of cases, respectively. In the infrachiasmatic corridor, the ophthalmic segment of the internal carotid artery and superior hypophyseal arteries were always visible through the SRPS. The mean width and height of the prechiasmatic sulcus were 13.2 mm and 9.6 mm, respectively. The mean distances from the midpoint of the AComm to the anterior margin of the optic chiasm (OCh) was 5.3 mm. The mean width of the infrachiasmatic corridor was 12.3 mm at the level of the proximal margin of the ophthalmic segment of the internal carotid artery. The mean distances from the posterior superior limit of the pituitary stalk to the basilar tip and oculomotor nerve were 9.7 mm and 12.3 mm, respectively. CONCLUSIONS: The SRPS provides access to the main neurovascular and cisternal surgical landmarks of the suprachiasmatic and infrachiasmatic corridors. This anatomical area constitutes the key part of the approach to the suprasellar area. To afford adequate surgical maneuverability, the transplanum or transtuberculum approaches are usually a necessary extension.

Combined endoscopic endonasal transpterygoid and sublabial transmaxillary approaches for a large infratemporal fossa trigeminal schwannoma.

BACKGROUND: Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF). METHOD: We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video. CONCLUSION: A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs.

The endonasal midline inferior intercavernous approach to the cavernous sinus: technical note, cadaveric step-by-step illustration, and case presentation.

PURPOSE: Traditional endoscopic endonasal approaches to the cavernous sinus (CS) open the anterior CS wall just medial to the internal carotid artery (ICA), posing risk of vascular injury. This work describes a potentially safer midline sellar entry point for accessing the CS utilizing its connection with the inferior intercavernous sinus (IICS) when anatomically present. METHODS: The technique for the midline intercavernous dural access is described and depicted with cadaveric dissections and a clinical case. RESULTS: An endoscopic endonasal approach exposed the periosteal dural layer of anterior sella and CS. The IICS was opened sharply in midline through its periosteal layer. The feather knife was inserted and advanced laterally within the IICS toward the anterior CS wall, thereby gradually incising the periosteal layer of the IICS. The knife was turned superiorly then inferiorly in a vertical direction to open the anterior CS wall. This provided excellent access to the CS compartments, maintained the meningeal layer of the IICS and the medial CS wall, and avoided an initial dural incision immediately adjacent to the ICA. CONCLUSION: The midline intercavernous dural access to the CS assisted by a 90° dissector-blade is an effective modification to previously described techniques, with potentially lower risk to the ICA.

Aneurismal subarachnoid hemorrhage during the COVID-19 outbreak in a Hub and Spoke system: observational multicenter cohort study in Lombardy, Italy.

BACKGROUND: Lombardy was the most affected Italian region by the first phase of the COVID-19 pandemic and underwent urgent reorganization for the management of emergencies, including subarachnoid hemorrhage from a ruptured cerebral aneurysm (aSAH). The aim of the study was to define demographics, clinical, and therapeutic features of aSAH during the COVID-19 outbreak and compare these with a historical cohort. METHODS: In this observational multicenter cohort study, patients aged 18 years or older, who were diagnosed with aSAH at the participating centers in Lombardy from March 9 to May 10, 2020, were included (COVID-19 group). In order to minimize bias related to possible SAH seasonality, the control group was composed of patients diagnosed with aSAH from March 9 to May 10 of the three previous years, 2017-2018-2019 (pre-pandemic group). Twenty-three demographic, clinical, and therapeutic features were collected. Statistical analysis was performed. RESULTS: Seventy-two patients during the COVID-19 period and 179 in the control group were enrolled at 14 centers. Only 4 patients were positive for SARS-CoV-2. The "diagnostic delay" was significantly increased (+ 68%) in the COVID-19 group vs. pre-pandemic (1.06 vs. 0.63 days, respectively, p-value = 0.030), while "therapeutic delay" did not differ significantly between the two periods (0.89 vs. 0.74 days, p-value = 0.183). Patients with poor outcome (GOS at discharge from 1 to 3) were higher during the COVID-19 period (54.2%) compared to pre-pandemic (40.2%, p = 0.044). In logistic regression analysis, in which outcome was the dichotomized Glasgow Outcome Scale (GOS), five variables showed p-values < 0.05: age at admission, WFNS grade, treatment (none), days in ICU, and ischemia. CONCLUSIONS: We documented a significantly increased "diagnostic delay" for subarachnoid hemorrhages during the first COVID-19 outbreak in Lombardy. However, despite the dramatic situation that the healthcare system was experiencing, the Lombardy regional reorganization model, which allowed centralization of neurosurgical emergencies such as SAHs, avoided a "therapeutic delay" and led to results overall comparable to the control period.