Development and validation of a molecular classifier of meningiomas.

Background: Meningiomas exhibit considerable clinical and biological heterogeneity. We previously identified four distinct molecular groups (immunogenic, NF2-wildtype, hypermetabolic, proliferative) that address much of this heterogeneity. Despite the utility of these groups, the stochasticity of clustering methods and the use of multi-omics data for discovery limits the potential for classifying prospective cases.

Complications: skull base and cerebrovascular.

Neurosurgical complications are a rich source for learning, but they are grossly underutilized for the purpose of surgeon education. Details of the complications, which make them all the more powerful as teaching tools, are restricted to morbidity and mortality conferences behind closed doors, and open discussions of the topic are blurred by hypotheticals in order to shield the presenters from medicolegal risks. In this issue of Neurosurgical Focus, 9 neurosurgeons were invited to present complications they encountered along with the details and specific lessons they learned.

Surgical anatomy of the inferior hypophyseal artery and its relevance for endoscopic endonasal skull base surgery.

Objective: The inferior hypophyseal arteries (IHAs) are intimately related to pituitary and cavernous sinus (CS) lesions. There is still no anatomical study specifically analyzing the IHAs. The aim of this study was to investigate the surgical anatomy and variations of the IHA, and to translate this knowledge into surgical practice.

Surgical anatomy of the carotid sympathetic plexus in endoscopic endonasal approaches: strategies for preventing Horner syndrome.

Objective: Endoscopic endonasal approaches (EEAs) specifically for procedures involving manipulation of the internal carotid artery (ICA), such as the transcavernous and translacerum approaches, confer a potential risk of carotid sympathetic plexus injury, potentially leading to postganglionic Horner syndrome. The primary aim of this study was to delineate the surgical anatomy of the carotid sympathetic plexus from an endoscopic endonasal perspective, offering insights to facilitate intraoperative anatomical identification and injury prevention.

Methods: A comprehensive dissection was conducted on 20 silicone-injected, lightly embalmed postmortem human heads.

Extended transcavernous posterior clinoidectomy in endoscopic endonasal surgery.

Objective: Mastery of the posterior clinoidectomy technique is of utmost importance for neurosurgeons who specialize in endoscopic endonasal approaches, because the posterior clinoid process (PCP) is commonly involved in chondroid tumor resection. Three main techniques for posterior clinoidectomy have been developed: intradural, extradural, and transcavernous interdural. The authors introduce here a novel technical variant in which the transcavernous approach is extended to the dorsal clinoidal space after transection of the caroticoclinoid ligament, and they elaborate on its clinical application on the basis of anatomical dissections and radiological studies.

Preoperative stereotactic radiosurgery for patients with 1-4 brain metastases: A single-arm phase 2 trial outcome analysis (NCT03398694).

Background: Stereotactic radiosurgery (SRS) following surgical resection is the standard of care for patients with symptomatic oligo brain metastasis (BM), however, it is associated with 10-15% local failure. Targeting a resection cavity is imprecise, thus preoperative radiosurgery where the target is well-defined may be superior, however, the efficacy of preoperative SRS has not yet been tested in a clinical trial.

Methods: We conducted a phase 2, single-arm trial of preoperative SRS followed by surgical resection in patients with 1-4 symptomatic oligo BMs (NCT03398694) with the primary objective of measuring 6-month local control (LC).

Lateral compartment of the cavernous sinus from the endoscopic endonasal approach: anatomical considerations and surgical relevance to adenoma surgery.

Objective: The cavernous sinus (CS) has 4 compartments: superior, inferior, posterior, and lateral. Among these, the lateral compartment is the most common location for residual tumor, given the risk of neurovascular injury. The authors' study aimed to delineate the anatomical landmarks in this area and illustrate the technical nuances of the lateral transcavernous approach.

Autologous stem cell transplantation in adults with atypical teratoid rhabdoid tumor: a case report and review.

Atypical teratoid rhabdoid tumor (ATRT) is a rare and highly aggressive primary CNS neoplasm, predominantly observed in children. The use of autologous stem cell transplantation (ASCT) in pediatric ATRT has shown promise; however, its utility in adult ATRT remains unclear. This study presents the case of an adult patient with ATRT who is in remission after ASCT and reviews the literature on ASCT in adults with ATRT.

Endoscopic Endonasal Approach to the Ventral Petroclival Fissure: Anatomical Findings and Surgical Techniques.

 The endoscopic endonasal approach has emerged as an excellent option for the treatment of lesions involving the petroclival fissure (PCF). Here, we investigate the surgical anatomy of the ventral PCF and its application in endoscopic endonasal surgery.  Sixteen head specimens were used to investigate the anatomical features of PCF and relevant technical nuances in translacerum, extreme medial, and contralateral transmaxillary (CTM) approaches.

Metabolic Insight into Glioma Heterogeneity: Mapping Whole Exome Sequencing to In Vivo Imaging with Stereotactic Localization and Deep Learning.

Intratumoral heterogeneity (ITH) complicates the diagnosis and treatment of glioma, partly due to the diverse metabolic profiles driven by underlying genomic alterations. While multiparametric imaging enhances the characterization of ITH by capturing both spatial and functional variations, it falls short in directly assessing the metabolic activities that underpin these phenotypic differences. This gap stems from the challenge of integrating easily accessible, colocated pathology and detailed genomic data with metabolic insights.

Creating a neuroanatomy education model with augmented reality and virtual reality simulations of white matter tracts.

Objective: The utilization of digital technologies has experienced a notable surge, particularly in cases where access to cadavers is constrained, within the context of practical neuroanatomy training. This study evaluates augmented reality (AR)- and virtual reality (VR)-based educational models for neuroanatomy education.

Methods: Three-dimensional models were created using advanced photogrammetry.

Genomic analysis of human brain metastases treated with stereotactic radiosurgery reveals unique signature based on treatment failure.

Stereotactic radiosurgery (SRS) has been shown to be efficacious for the treatment of limited brain metastasis (BM); however, the effects of SRS on human brain metastases have yet to be studied. We performed genomic analysis on resected brain metastases from patients whose resected lesion was previously treated with SRS. Our analyses demonstrated for the first time that patients possess a distinct genomic signature based on type of treatment failure including local failure, leptomeningeal spread, and radio-necrosis.

Image-Based Assessment of Natural Killer Cell Activity against Glioblastoma Stem Cells.

Glioblastoma (GBM) poses a significant challenge in oncology and stands as the most aggressive form of brain cancer. A primary contributor to its relentless nature is the stem-like cancer cells, called glioblastoma stem cells (GSCs). GSCs have the capacity for self-renewal and tumorigenesis, leading to frequent GBM recurrences and complicating treatment modalities.

The Temporoparietal Fascia Flap Transposition Technique for Ventral Skull Base Reconstruction: Anatomic Analysis and Surgical Application.

Background And Objectives: The temporoparietal fascia (TPF) flap is an alternative for revision endoscopic skull base reconstruction in the absence of the nasoseptal flap, and we aimed to investigate the anatomy and surgical application of TPF flap transposition in endoscopic endonasal surgery.

Methods: Six lightly embalmed postmortem human heads and 30 computed tomography angiography imaging scans were used to analyze the anatomic features of the TPF flap transposition technique. Three cases selected from a 512 endoscopic endonasal cases database were presented for the clinical application of the TPF flap.