From Vesalius to Modern Neuroanatomical Training: The "Surgical Grammar" for the Next Generation of Neurosurgeons in Italy.

Anatomical knowledge plays a crucial role in the field of neurosurgery, originating from the rigorous requirements of surgical training. The study examines the training programs for young and future generations of neurosurgeons, highlighting the significance of rigorous dissection program in the laboratory of anatomy along with the challenges they face. It also details the training paths of aspiring surgeons, focusing on the high demands and challenges encountered in the anatomy laboratory and in a real surgical scenario.

Impact of augmented reality fiber tractography on the extent of resection and functional outcome of primary motor area tumors.

Objective: This study aimed to evaluate the impact of augmented reality intraoperative fiber tractography (AR-iFT) on extent of resection (EOR), motor functional outcome, and survival of patients with primary motor area (M1) intra-axial malignant tumors.

Methods: Data obtained from patients who underwent AR-iFT for M1 primary tumors were retrospectively analyzed and compared with those from a control group who underwent unaugmented reality intraoperative fiber tractography (unAR-iFT). A full asleep procedure with electrical stimulation mapping and fluorescein guidance was performed in both groups.

Intraoperative Augmented Reality Fiber Tractography for Primary Motor Area Glioma Resection.

The implementation of intraoperative augmented reality fiber tractography (iAR-FT) into the surgical workflow for high-grade supratentorial gliomas has been shown to be effective and safe in maximizing the extent of resection and progression-free survival through the surgeon's enhanced 3-dimensional awareness of the spatial localization of fiber tracts. Primary motor area tumors present special challenges due to the high eloquence of the precentral gyrus and risk of postoperative onset or worsening of motor deficits, as well as limited postoperative plasticity. Although essential, electrical stimulation mapping (ESM) techniques have a number of limitations with respect to primary motor pathways, including a higher risk of intraoperative stimulation-evoked seizures, a risk of false negatives in the presence of preoperative deficits, a nonnegligible risk of permanent deterioration even in the presence of negative stimulation maps, and, most importantly, limited spatial resolution.

Comparative Analysis of Surgical Working Corridors for Meckel Cave Trigeminal Schwannomas: A Quantitative Anatomic Study.

Background And Objectives: Volumetric analysis of the working corridors of the interdural approach to the Meckel cave may lead to a selection of routes which are anatomically more advantageous for trigeminal schwannoma resection. The herein-reported anatomic study quantitively compares the infratrochlear (IT) transcavernous, anteromedial (AM), and anterolateral (AL) corridors, highlighting their feasibility, indications, advantages, and limitations.

Methods: Anatomic boundaries and depth of Meckel cave, porus trigeminus, IT transcavernous, AM, and AL corridors were identified in 20 formalin-fixed latex-injected cadaveric heads and were subsequently measured.

Extracranial Jugular Foramen Schwannomas Treated with the Extreme Lateral Juxtacondylar Approach: Surgical Technique and Our Experience.

Background: Schwannoma that arises in the jugular foramen (JF) represents an important challenge for neurosurgeons for its precise location, extension, and neurovascular relationship. Nowadays, different managements are proposed. In this study, we present our experience in the treatment of extracranial JF schwannomas (JFss) with the extreme lateral juxtacondylar approach (ELJA).

Optic Foraminotomy versus Anterior Clinoidectomy for Small Superior-Projecting Paraclinoid Aneurysms: Visual and Angiographic Outcome Evaluation.

Introduction: Optic foraminotomy (OF) has been recently proposed as an alternative to anterior clinoidectomy (AC) for selected types of paraclinoid aneurysms. In this study, OF and AC were compared for small superior-projecting paraclinoid aneurysms assuming visual and angiographic results as outcome measures. Indications for OF are also discussed.

First documented case of intracranial falcine malignant peripheral nerve sheath tumor: illustrative case.

Background: The authors reported the first documented case of intracranial extraaxial nonneurofibromatosis type 1-related nontriton malignant peripheral nerve sheath tumor (MPNST) originating from the falx cerebri.

Observations: A 34-year-old man with headache, short-term memory deficit, postural instability, and blurred vision presented with a large heterogenous contrast-enhanced intraventricular cystic lesion originating from the free margin of the falx cerebri. The patient received surgery using the right posterior interhemispheric approach.

Gene Polymorphisms Increasing the Risk of Intracranial Aneurysms: Interleukin-1β -511C>T (Part I).

Introduction Intracranial aneurysms (IAs) are devastating cerebrovascular diseases with multifactorial etiology. The role of inflammation is indisputable, and interleukins are pivotal in supporting local inflammatory pathways and endothelial dysfunction at the aneurysm wall. In the light of insufficient evidence reported in the literature, this meta-analysis was aimed to investigate the genetic linkage between IL-1β (rs16944) -511C>T polymorphisms and IAs susceptibility.

Gene Polymorphisms Increasing the Risk of Intracranial Aneurysms: Interleukin-6 -174G>C and -572G>C (Part II).

Introduction The interleukin-6 (IL-6), a proinflammatory cytokine, supports the adaptive immune response and regulates inflammatory processes. The -174 G>C and -572 G>C promoter polymorphisms of the IL-6 gene take part in the pathogenesis of intracranial aneurysms (IAs) and influence the clinical presentation of subarachnoid hemorrhage. This meta-analysis purposes to evaluate whether and which IL-6 allelic variations are related to a risk of IAs formation.

Pterional Approach.

The pterional approach is a workhorse in neurosurgery, to the point where perfect knowledge of its execution is essential in neurosurgical daily practice. The pterional transsylvian corridor is used to treat aneurysms involving anterior circulation, basilar apex, the proximal segment of the superior cerebellar and posterior cerebral artery, arteriovenous malformations and cavernous hemangiomas of the basal forebrain, anterior and middle skull base tumors, gliomas of the frontal, parietal, and temporal opercula, insula, mediobasal temporal region, cerebral peduncles, interpeduncular fossa, and also orbital lesions. We herein overview the core technique and variations of the pterional approach aimed at broadening surgical freedom and decreasing the risk of approach-related complications.

Cranio-Orbito-Zygomatic Approach.

The cranio-orbito-zygomatic (COZ) approach consists of an extension of the pterional approach characterized by the removal of the superolateral part of the orbital rim and zygoma. This key step tremendously increases the angular exposure to some deep targets and overall surgical freedom to the lesion. In this article we review the technical variations of the COZ approach, mainly focusing on the differential quantitative effects coming from the orbital osteotomy compared to the zygomatic one.

Far Lateral Approach.

The far lateral approach is an inferolateral extension of the lateral suboccipital approach. Designed for clipping of the aneurysms of the vertebrobasilar junction and proximal segments of the posterior inferior cerebellar artery, it became over the years a workhorse approach for ventral foramen magnum meningiomas and other intradural lesions located anterior to the dentate ligament.  This article summarizes the technical key aspects of the far lateral approach and transcondylar, supracondylar, and paracondylar extension.

Cranio-Orbito-Zygomatic Approach: Core Techniques for Tailoring Target Exposure and Surgical Freedom.

Background: The cranio-orbito-zygomatic (COZ) approach is a workhorse of skull base surgery, and each of its steps has a precise effect on target exposure and surgical freedom. The present study overviews the key techniques for execution and tailoring of the COZ approach, focusing on the quantitative effects resulting from removal of the orbitozygomatic (OZ) bar, orbital rim, and zygomatic arch.

Methods: A PRISMA-based literature review was performed on the PubMed/Medline and Web of Science databases using the main keywords associated with the COZ approach.

A Dedicated Tool for Presurgical Mapping of Brain Tumors and Mixed-Reality Navigation During Neurosurgery.

Brain tumor surgery requires a delicate tradeoff between complete removal of neoplastic tissue while minimizing loss of brain function. Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) have emerged as valuable tools for non-invasive assessment of human brain function and are now used to determine brain regions that should be spared to prevent functional impairment after surgery. However, image analysis requires different software packages, mainly developed for research purposes and often difficult to use in a clinical setting, preventing large-scale diffusion of presurgical mapping.

Postcentral Gyrus High-Grade Glioma: Maximal Safe Anatomic Resection Guided by Augmented Reality with Fiber Tractography and Fluorescein.

Intraaxial tumors of the central lobe are challenging lesions to deal with because of the high eloquence of this anatomic area. Diffusion tensor imaging magnetic resonance imaging and fluorescein (F) have proven to be useful in the planning and execution, respectively of glioma surgery. Nevertheless, the advantages of intraoperative use of augmented reality (AR) with diffusion tensor imaging-based high-definition fiber tractography (HDFT) are still underestimated.

Shedding the Light on the Natural History of Intracranial Aneurysms: An Updated Overview.

The exact molecular pathways underlying the multifactorial natural history of intracranial aneurysms (IAs) are still largely unknown, to the point that their understanding represents an imperative challenge in neurovascular research. Wall shear stress (WSS) promotes the genesis of IAs through an endothelial dysfunction causing an inflammatory cascade, vessel remodeling, phenotypic switching of the smooth muscle cells, and myointimal hyperplasia. Aneurysm growth is supported by endothelial oxidative stress and inflammatory mediators, whereas low and high WSS determine the rupture in sidewall and endwall IAs, respectively.

The Modular Concept in Skull Base Surgery: Anatomical Basis of the Median, Paramedian and Lateral Corridors.

Introduction A thorough understanding of skull base anatomy is imperative to perform safely and effectively any skull base approach. In this article, we examine the microsurgical anatomy of the skull base by proposing a modular topographic organization in the median, paramedian, and lateral surgical corridors in relation to transcranial and endoscopic approaches. Methods Five dry skulls were studied focusing on the intracranial and exocranial skull base.

Microsurgical Neurovascular Anatomy of the Brain: The Anterior Circulation (Part I).

Introduction Treatment of cranial neurovascular pathology requires a detailed understanding of the brain, head, and neck vasculature. This study aims at a comprehensive overview of the microsurgical anatomy of the anterior cerebral circulation. Methods Five formalin-fixed adult cadaveric heads were used.

Microsurgical Neurovascular Anatomy of the Brain: The Posterior Circulation (Part II).

Introduction Vascular complications of posterior fossa surgery are often deadly although widely preventable through in-depth knowledge of the microsurgical neurovascular anatomy of the infratentorial region and careful surgical planning.   The target of this study is to provide a synoptic overview of the normal anatomy and anatomic variants of the infratentorial neurovascular system, critical to safely operate tumors and neurovascular pathologies of the posterior fossa. Methods Two fresh-frozen and five formalin-fixed cadaveric heads were used.

Supratentorial high-grade gliomas: maximal safe anatomical resection guided by augmented reality high-definition fiber tractography and fluorescein.

Objective: The theoretical advantages of augmented reality (AR) with diffusion tensor imaging (DTI)-based high-definition fiber tractography (HDFT) and sodium fluorescein (F) in high-grade glioma (HGG) surgery have not been investigated in detail. In this study, the authors aimed to evaluate the safety and efficacy profiles of HDFT-F microscope-based AR cytoreductive surgery for newly diagnosed supratentorial HGGs.

Methods: Data of patients with newly diagnosed supratentorial HGGs who underwent surgery using the AR HDFT-F technique were reviewed and compared with those of a cohort of patients who underwent conventional white-light surgery assisted by infrared neuronavigation.

The Preoperative Functional Downgrading of Brain AVMs.

The actual role of preoperative embolization of brain arteriovenous malformations (AVMs) is undervalued.The present study aims to describe the effectiveness, safety, technics, and results of the endovascular-based functional downgrading of brain AVMs.Data regarding 31 Spetzler-Martin (SM) grade III AVMs that consecutively underwent a combined endovascular-surgical treatment were reviewed.

Microneurosurgery for Paraclinoid Aneurysms in the Context of Flow Diverters.

The advent of flow diverter (FD) stents has apparently reduced the role of microneurosurgery for paraclinoid aneurysms despite sparse high-quality evidence about their long-term effects.The present study critically reviews the overall results of a microneurosurgical series of 57 paraclinoid aneurysms.Of these aneurysms, 47.

Posterior Circulation Aneurysms: A Critical Appraisal of a Surgical Series in Endovascular Era.

The advent of the endovascular era has apparently decreased the role of microneurosurgery for many of the posterior circulation aneurysms. This study consists of a critical appraisal of a retrospective surgical series regarding posterior circulation aneurysms, targeted to define whether microneurosurgery still has a role for some of these. In 28 years, 157 aneurysms were surgically treated, 98 of which ruptured.