Lumbar Spinous Process-Splitting Technique for Ligamentum Flavum Cyst Removal

BACKGROUND

 Laminotomy for lumbar stenosis is a well-defined procedure and represents a routine in every neurosurgical department. It is a common experience that the uni- or bilateral paraspinal muscle detachment, together with injury of the supra- and interspinous ligaments, can lead to postoperative pain. In the literature, the application of a minimally invasive technique, the lumbar spinous process-splitting (LSPS) technique, has been reported.

METHODS

 In this study, we present a case series of 12 patients who underwent LSPS from September 2019 to April 2020. Two patients had a cyst of the ligamentum flavum, eight a single-level lumbar canal stenosis (LCS), and two a two-level LCS. Moreover, we propose a novel morphological classification of postoperative muscle atrophy and present volumetric analysis of the decompression achieved.

RESULTS

 There were no complications related to this technique. In all patients, the vertebral canal area was more than doubled by the procedure. The muscle sparing showed grade A, according to our classification.

CONCLUSION

 To our knowledge, this is the first description of this surgical technique and the first LSPSL case series in Europe. Furthermore, cases of ligamentum flavum cyst removal using this safe and effective technique have not yet been reported.

Primary Intracranial Gliosarcoma: Is It Really a Variant of Glioblastoma? An Update of the Clinical, Radiological, and Biomolecular Characteristics

Gliosarcomas (GS) are sporadic malignant tumors classified as a Glioblastoma (GBM) variant with IDH-wild type phenotype. It appears as a well-circumscribed lesion with a biphasic, glial, and metaplastic mesenchymal component. The current knowledge about GS comes from the limited literature. Furthermore, recent studies describe peculiar characteristics of GS, such as hypothesizing that it could be a clinical-pathological entity different from GBM. Here, we review radiological, biomolecular, and clinical data to describe the peculiar characteristics of PGS, treatment options, and outcomes in light of the most recent literature. A comprehensive literature review of PubMed and Web of Science databases was conducted for articles written in English focused on gliosarcoma until 2023. We include relevant data from a few case series and only a single meta-analysis. Recent evidence describes peculiar characteristics of PGS, suggesting that it might be a specific clinical-pathological entity different from GBM. This review facilitates our understanding of this rare malignant brain tumor. However, in the future we recommend multi-center studies and large-scale metanalyses to clarify the biomolecular pathways of PGS to develop new specific therapeutic protocols, different from conventional GBM therapy in light of the new therapeutic opportunities.

The Superficial Anastomosing Veins of the Human Brain Cortex: A Microneurosurgical Anatomical Study

Introduction: In this microneurosurgical and anatomical study, we characterized the superficial anastomosing veins of the human brain cortex in human specimens.

Material and Methods: We used 21 brain preparations fixed in formalin (5%) that showed no pathological changes and came from the autopsy sections. The superficial veins were dissected out of the arachnoid with the aid of a surgical microscope.

Results: We dissected nine female and 12 male brain specimens, with an average age of 71 ± 11 years (range 51–88 years). We classified the superficial veins in five types: (I) the vein of Trolard as the dominat vein; (II) the vein of Labbé as the dominant vein; (III) a dominant sylvian vein group, and the veins of Trolard and Labbé nonexistent or only rudimentary present without contact to the Sylvian vein group; (IV) very weak sylvian veins with the veins of Trolard and Labbé codominant; and V) direct connection of Trolard and Labbé bypassing the Sylvian vein group. The vein of Trolard was dominant (Type I) in 21.4% and the vein of Labbé (Type II) in 16.7%. A dominant sylvian vein group (Type III) was found in 42.9%. Type IV and Type V were found in 14.3 and 4.7% respectively.

Conclusion: No systematic description or numerical distribution of the superior anastomotic vein (V. Trolard) and inferior anastomotic vein (V. Labbé) has been found in the existing literature. This study aimed to fill this gap in current literature and provide data to neurosurgeons for the practical planning of surgical approaches.

Primary Extracranial Meningiomas of the Head and Neck

Meningiomas represent the most common benign histological tumor of the central nervous system. Usually, meningiomas are intracranial, showing a typical dural tail sign on brain MRI with Gadolinium, but occasionally they can infiltrate the skull or be sited extracranially. We present a systematic review of the literature on extracranial meningiomas of the head and neck, along with an emblematic case of primary extracranial meningioma (PEM), which provides further insights into PEM management. A literature search according to the PRISMA statement was conducted from 1979 to June 2021 using PubMed, Web of Science, Google Scholar, and Scopus databases, searching for relevant Mesh terms (primary extracranial meningioma) AND (head OR neck). Data for all patients were recorded when available, including age, sex, localization, histological grading, treatment, possible recurrence, and outcome. A total of 83 published studies were identified through PubMed, Google Scholar, and Scopus databases, together with additional references list searches from 1979 to date. A total of 49 papers were excluded, and 34 manuscripts were considered for this systematic review, including 213 patients. We also reported a case of a 45-year-old male with an extracranial neck psammomatous meningioma with sizes of 4 cm × 3 cm × 2 cm. Furthermore, whole-body ⁶⁸Ga-DOTATOC PET/CT was performed, excluding tumor spread to other areas. Surgical resection of the tumor was accomplished, as well as skin flap reconstruction, obtaining radical removal and satisfying wound healing. PEMs could suggest an infiltrative and aggressive behavior, which has never found a histopathological correlation with a malignancy (low Ki-67, <5%). Whole-body ⁶⁸Ga-DOTATOC PET/CT should be considered in the patient’s global assessment. Surgical removal is a resolutive treatment, and the examination of frozen sections can confirm the benignity of the lesion, reducing the extension of the removal of healthy tissue surrounding the tumor.

Perforating Arteries of the Lemniscal Trigone: A Microsurgical Neuroanatomic Description

Background: The perforating arteries in the dorsolateral zone of the midbrain play a crucial role in the functions of the brain stem. Their damage due to herniation, pathological lesions, or surgery, favored by the narrow tentorial incisura, can lead to hemorrhages or ischemia and subsequently to severe consequences for the patient. Objective: In literature, not much attention has been directed to the perforating arteries in the lemniscus; in fact, no reports on the perforators of this anatomical region are available. The present study aims to a detailed analysis of the microanatomy and the clinical implications of these perforators, in relation to the parent vessels. We focused on the small vessels that penetrate the midbrain's dorsolateral surface, known as lemniscal trigone, to understand better their microanatomy and their functional importance in the clinical practice during the microsurgical approach to this area. Methods: Eighty-seven alcohol-fixed cadaveric hemispheres (44 brains) without any pathological lesions provided the material for studying the perforating vessels and their origin around the dorsolateral midbrain using an operating microscope (OPMI 1 FC, Zeiss). Measurements of the perforators' distances, in relation to the parent vessels, were taken using a digital caliper. Results: An origin from the SCA could be found in 70.11% (61) and from the PCA in 27.58% (24) of the hemispheres. In one hemisphere, an origin from the posterior choroidal artery was found (4.54%). No perforating branches were discovered in 8.04% of specimens (7). Conclusion: The perforating arteries of the lemniscal trigone stem not only from the superior cerebellar artery (SCA), as described in the few studies available in literature, but also from the posterior cerebral artery (PCA). Therefore, special attention should be paid during surgery to spare those vessels and associated perforators. A comprehensive understanding of the lemniscal trigone's perforating arteries is vital to avoid infarction of the brainstem when treating midbrain tumors or vascular malformations.

Largest neurosurgical social media group and its impact on communication and research

BACKGROUND

The use of social media to communicate and disseminate knowledge has increased exponentially, especially in the field of neurosurgery. 'Neurosurgery cocktail' (NC) was developed by a group of young neurosurgeons as a means of sharing didactic materials and clinical experiences via social media. It connects 35.000 neurosurgeons worldwide on multiple platforms, primarily Facebook and Twitter. Given the rising utilization of social media in neurosurgery, the popularity of NC has also increased since its inception. In this study, the authors surveyed the social media analytics of NC for both Facebook and Twitter. Besides, we reviewed the literature on the use of social media in neurosurgery.

METHODS

Facebook and Twitter metrics were extracted through each respective platform's analytics tools from December 2020 (earliest available date for data analysis) through January 2021. A literature search was conducted using PubMed (MEDLINE) and Scopus databases.

RESULTS

On Facebook, as of January 2021, the group had a total of 25.590 members (87.6% male), most commonly (29%) between 35 and 44 years of age with over 100 countries were represented. As of January 2021, they had amassed 6457 followers on Twitter. During the last 28 d between December 2020 and January 2021, the account published 65 tweets that garnered a total of 196,900 impressions. Twelve articles were identified in our literature review on the use of social media within the neurosurgical community.

CONCLUSIONS

NC is one of the most widely utilized neurosurgical social media resources available. Sharing knowledge has been broadened thanks to the recent social media evolution, and NC has become a leading player in disseminating neurosurgical knowledge.

Multimodal Simulation of a Novel Device for a Safe and Effective External Ventricular Drain Placement

Background

External ventricular drain (EVD) placement is mandatory for several pathologies. The misplacement rate of the EVD varies widely in literature, ranging from 12.3 to 60%. The purpose of this simulation study is to provide preliminary data about the possibility of increasing the safety of one of the most common life-saving procedures in neurosurgery by testing a new device for EVD placement.

Methods

We used a novel guide for positioning the ventricular catheter (patent RM2014A000376). The trajectory was assessed using 25 anonymized head CT scans. The data sets were used to conduct three-dimensional computer-based and combined navigation and augmented reality-based simulations using plaster models. The data set inclusion criteria were volumetric head CT scan, without midline shift, of patients older than 18. Evans' index was used to quantify the ventricle's size. We excluded patients with slit ventricles, midline shift, skull fractures, or complex skull malformations. The proximal end of the device was tested on the cadaver.

Results

The cadaveric tests proved that a surgeon could use the device without any external help. The multimodal simulation showed Kakarla grade 1 in all cases but one (grade 2) on both sides, after right and left EVD placement. The mean Evans' index was 0.28. The geometric principles that explain the device's efficacy can be summarized by studying the properties of circumference and chord. The contact occurs, for each section considered, at the extreme points of the chord. Its axis, perpendicular to the plane tangent to the spherical surface at the entry point, corresponds to the direction of entry of the catheter guided by the instrument.

Conclusion

According to our multimodal simulation on cadavers, 3D computer-based simulation, 3D plaster modeling, 3D neuronavigation, and augmented reality, the device promises to offer safer and effective EVD placement. Further validation in future clinical studies is recommended.

Importance of Veins for Neurosurgery as Landmarks Against Brain Shifting Phenomenon: An Anatomical and 3D-MPRAGE MR Reconstruction of Superficial Cortical Veins

Modern neurosurgery uses preoperative imaging daily. Three-dimensional reconstruction of the cortical anatomy and of the superficial veins helps the surgeons plan and perform neurosurgical procedures much more safely. The target is always to give the patient maximum benefit in terms of outcome and minimize intraoperative and postoperative complications. This study aims to develop a method for the combined representation of the cerebral cortex anatomy and the superficial cerebral veins, whose integration is beneficial in daily practice. Only those patients who underwent surgical procedures with craniotomy and a large opening of the dura mater were included in this study, for a total of 23 patients, 13 females (56.5%) and 10 males (43.5%). The average age was 50.1 years. We used a magnetic resonance tomograph Magnetom Vision® 1.5T (Siemens AG). Two sequences were applied: a strongly T1-weighted magnetization-prepared rapid acquisition with gradient echo (MPRAGE) sequence to visualize cerebral anatomical structures, and a FLASH-2D-TOF angiography sequence to visualize the venous vessels on the cortical surface after the administration of a paramagnetic contrast agent. The two data sets were superimposed manually, co-registered in an interactive process, and merged to create a combined data set, segmented and visualized as a three-dimensional reconstruction. Furthermore, we present our method for visualizing superficial veins, which helps manage brain shift (BS). We also performed anatomical observations on the reconstructions. The reconstructions of the cortical and venous anatomy proved to be a valuable tool in surgical planning and positively influenced the surgical procedure. Due to the good correlation with the existing surgical site, this method should be validated on a larger cohort or in a multicentric study.

Slit-like hypertensive hydrocephalus: Report of a late, complex, and multifactorial complication in an oncologic patient

Background:

Several sophisticated techniques and many chemotherapy drugs have improved life expectancy of oncologic patients allowing us to observe late complications which present many years after the initial treatment.

Case Description:

We present a unique case of a patient affected by acute lymphoblastic leukemia at the age of 6 years, treated with whole brain radiotherapy and intrathecal chemotherapy, developing meningiomatosis and leptomeningeal alterations as late complications and the interaction of these two entities caused a peculiar form of hydrocephalus without ventricular dilation. The diagnosis of pseudotumor cerebri was excluded due the postradio/chemotherapy development of meningiomatosis, not present in a previously head magnetic resonance imaging, that exerted compression to the Sylvian aqueduct causing intracranial hypertension with papillary stasis without ventricles enlargement due to brain stiffness. Moreover, a peculiar intraoperative rubbery consistency of brain parenchyma was detected strengthening this complex diagnosis.

Conclusion:

At the best of our knowledge, this is the first report of obstructive hydrocephalus without ventricles dilation caused by brain stiffness related to late alterations of oncologic treatments. This report could be a guide for further complex patients diagnoses and for improving treatments efficacy.

Spontaneous Subgaleal Abscess Associated with Lung Adenocarcinoma: First Description of This Unusual Association

BACKGROUND

Primary, spontaneous, or de novo subgaleal abscesses represent extremely rare lesions usually related to patients with risk factors and predisposing conditions for infections. They are associated with high morbidity, and a proper diagnosis can be misleading. To the best of our knowledge, this is the first reported case of a de novo subgaleal abscess not related to previous traumatic head injury and associated with lung adenocarcinoma.

CASE DESCRIPTION

A 59-year-old man was admitted to our unit because he presented fever and a palpable subcutaneous right parietal mass. No history of traumatic head injury was mentioned. The patient underwent needle aspiration of the subgaleal lesion for microbiological, histological, and cytological examination, with negative response. Chest radiograph and then thoracic computed tomography scan revealed the presence of 2 lesions in the left lung. Complete removal with surgical debridement of the parietal bone lesion was performed due to the suspicion of an abscessualized skull metastasis from a primary lung adenocarcinoma.

CONCLUSIONS

We strongly suggest a patient global assessment in the event of subgaleal abscess without history of traumatic head injury, to treat eventual associated findings as soon as possible.

Thoracic Intradural-Extramedullary Epidermoid Tumor: The Relevance for Resection of Classic Subarachnoid Space Microsurgical Anatomy in Modern Spinal Surgery. Technical Note and Review of the Literature

BACKGROUND

Intradural epidermoid tumors of the spinal cord are commonly associated with spinal cord dysraphism or invasive procedures. We report the particular relationships between spinal subarachnoid compartments and thoracic intradural-extramedullary epidermoid tumor, highlighting the relevant anatomic changes that may influence microsurgery.

METHODS

A 40-year-old woman from compressive myelopathy owing to a thoracic epidermoid tumor extending from T3 to T4 and not associated with spina bifida, trauma, previous surgery, or lumbar spinal puncture underwent microsurgical excision. Accurate tumor membrane dissection, respecting spinal arachnoidal compartments, was performed. Reposition of a laminoplasty plateau helped in restoring thoracic spine anatomic integrity.

RESULTS

Safe gross total tumor resection was achieved. Complete neurologic recovery as well as absence of recurrent tumor was documented at 4-year follow-up. A literature review revealed only 2 other cases of "isolated" thoracic spine epidermoid tumor. However, description of the relationship between tumor membranes and spinal subarachnoid compartments was not available in either case.

CONCLUSIONS

A thorough knowledge of spinal subarachnoid space anatomy is helpful to distinguish between tumor membranes and arachnoidal planes and to achieve a safe and complete resection to avoid recurrences.

Out-of-third ventricle colloid cysts: review of the literature on pathophysiology, diagnosis and treatment of an uncommon condition, with a focus on headache

INTRODUCTION

Colloid cysts are rare benign intracranial lesions classically described as "third ventricle colloid cysts" because of their location within the third ventricle. These lesions' clinical and diagnostic features are mainly related to intermittent or persistent obstruction of foramina of Monro causing cerebrospinal fluid (CSF) circulation impairment and symptoms of raised intracranial pressure. Few reports on colloid cysts located outside the third ventricle have been published over the years. This paper aims to review the existing literature on out-of-third ventricle colloid cysts, and introduces a new illustrative case of lateral ventricle colloid cyst surgically managed with endoscopic technique.

EVIDENCE ACQUISITION

A literature review was performed through a Medline web-search, using "colloid cysts," "lateral ventricle colloid cysts," "fourth ventricle colloid cysts," "brain colloid cyst," "spinal colloid cysts" as keywords. All retrieved abstracts were screened and full-length text of papers suitable for inclusion were examined. An illustrative case has been added to the existing literature. A 45-year-old man complaining of recurrent headache underwent conservative treatment for 4 years. The unusual headache features as well as the uncommon onset and association with episodic mental impairment led to an initial diagnosis of anxiety disorder triggering the headache. A further worsening of headache and the lack of significant clinical benefit prompted further investigation. Computed-tomography (CT) of the brain showed asymmetrical dilatation of the right lateral ventricle, due to the presence of a cystic mass obstructing the foramen of Monroe. Patient underwent endoscopic resection of the cyst.

EVIDENCE SYNTHESIS

The literature review revealed 16 papers reported between 1952 and 2016. In all cases included histological diagnosis of colloid cyst had been obtained. Clinical and radiological features, as well as surgical management in each case have been analyzed. In the case here reported, histological examination documented a colloid cyst. The postoperative course was uneventful, with progressive resolution of headache.

CONCLUSIONS

Despite third ventricle colloid cysts are related to typical clinical and diagnostic features, non-third ventricle colloid cysts may be responsible for unusual clinical presentation, so making a correct diagnostic approach challenging. We submit that in cases of recurrent headache with unusual features and lacking signs of neurological deficits, a rare neurosurgical condition as an "ectopic" colloid cyst should be included in the differential diagnosis.

Nanoparticle-based cerebral drug-delivery systems and antiangiogenic approach in gliomas treatment

The efficacy of current anti-cancer multimodal therapeutic strategies in gliomas is limited by the lack of specific therapies against malignant cells and the prognosis in patients affected by cerebral gliomas remains very unfavorable. Glial tumors seem to be able to create a favorable environment for the invasion of neoplastic cells when they combine with the extracellular matrix through the up-regulation of crucial pathways such as angiogenesis and invasion. The major problem in brain drug delivery is the presence of the blood brain barrier which limits the delivery of many chemotherapeutic agents and other kinds of therapeutic molecules. This event often contributes to the failure of the treatment. Nanoparticle systems can represent ideal devices for delivery of specific compounds to brain tumors across the blood brain barrier. The specificity of hybridization makes antisense method an interesting strategy to selectively modulate the expression of genes involved in tumorigenesis. In this review we will focus on the mechanisms of angiogenesis into gliomas, their importance into tumor progression and the possibilities to block these mechanisms with new nanoparticle-based therapeutic strategies. We will also report the results of preclinical and/or clinical studies that adopt nanoparticle-based antiangiogenic therapeutic approach in cerebral gliomas, considering also some patents deal with antiangiogenic strategy.

Could nanoparticle systems have a role in the treatment of cerebral gliomas?

Malignant brain tumors are difficult to manage clinically and are associated with high rates of morbidity and mortality. Late diagnosis and the limitations of conventional therapies that may result from inefficient delivery of the therapeutic or contrast agent to brain tumors due to the blood-brain barrier and nonspecificity of the agents, are major reasons for this unsolved clinical problem. Nanotechnology involves the design, synthesis, and characterization of materials and devices that have a functional organization in at least one dimension on the nanometer scale. The nanoparticle has emerged as a potential vector for brain delivery, able to overcome the difficulties of modern strategies. Moreover, multifunctionality can be engineered into a single nanoplatform so that it can provide tumor-specific detection, treatment, and follow-up monitoring. This review reports the latest research in nanoparticle-based glioma treatment.

FROM THE CLINICAL EDITOR

In recent years, nanoparticles have emerged as potential delivery vectors targeting brain tumors, including multifunctional NP-s allowing tumor-specific detection, treatment, and follow-up monitoring. This review summarizes the latest research in nanoparticle-based glioma treatment.

Nanotechnology platforms in diagnosis and treatment of primary brain tumors

Despite aggressive multimodal strategies, the prognosis in patients affected by primary brain tumors is still very unfavorable. Glial tumors seem to be able to create a favorable environment for the invasion of neoplastic cells into the cerebral parenchyma when they interact with the extracellular matrix via cell surface receptors. The major problem in drug delivery into the brain is due to the presence of the blood brain barrier which limits drug penetration. Nanotechnology involves the design, synthesis and characterization of materials that have a functional organization at least in one dimension on the nanometer scale. Nanoengineered devices in medical applications are designed to interface and interact with cells and tissues at the molecular level. Nanoparticle systems can represent ideal devices for delivery of specific compounds to brain tumors, across the blood brain barrier. In this brief review, we report the results of studies related to the emerging novel applications of nanoparticle systems in diagnosis and treatment of primary brain tumors, and also the patents of studies that adopt nanoparticle systems as drug delivery carriers in brain tumor diagnosis and therapy.

Antisense oligonucleotides as innovative therapeutic strategy in the treatment of high-grade gliomas

Despite the intensive recent research in cancer therapy, the prognosis in patients affected by high-grade gliomas is still very unfavorable. The efficacy of classical anti-cancer strategies is seriously limited by lack of specific therapies against malignant cells. The extracellular matrix plays a pivotal role in processes such as differentiation, apoptosis, and migration in both the normal and the pathologic nervous system. Glial tumors seem to be able to create a favorable environment for the invasion of glioma cells in cerebral parenchyma when they combine with the extracellular matrix via cell surface receptors. Glioma cells synthesize matrix proteins, such as tenascin, laminin, fibronectin that facilitate the tumor cell's motility. New treatments have shown to hit the acting molecules in the tumor growth and to increase the efficacy and minimize the toxicity. Antisense oligonucleotides are synthetic stretches of DNA which hybridize with specific mRNA strands. The specificity of hybridization makes antisense method an interesting strategy to selectively modulate the expression of genes involved in tumorigenesis. In this review we will focus on the mechanisms of action of antisense oligonucleotides and report clinical and experimental studies on the treatment of high-grade gliomas. We will also report the patents of preclinical and/or clinical studies that adopt the antisense oligonucleotide therapy list in cerebral gliomas.

Five-level one-piece laminoplasty for extensive tumors of the lumbar spine

The authors describe the surgical method and results of nonexpansive one-piece multivel laminoplasty of the whole lumbar spine, for microsurgical resection of extensive spinal tumors. This technique allows a very comfortable approach to the dura and intradural content, as well as a perfect replacement of the posterior spinal arch with supporting elements and an optimal reconstruction of the spinal anatomy. A nonexpansive whole lumbar one-piece laminoplasty was performed for resection of extensive multilevel lumbar tumors. The authors report an illustrative case of a patient who initially presented with a three-year history of numbness on both legs and progressive difficulty in walking. Two months before admission, he complained of bilateral sciatica and rectourinary dysfunction. A spinal magnetic resonance imaging (MRI) documented an intradural tumor extending from L2 to S1. The patient underwent a nonexpansive whole lumbar one-piece laminoplasty and microsurgical removal of the intradural lesion. The postoperative course was uneventful, the sensory disturbances and bilateral sciatica early recovered while rectourinary disturbance gradually improved up to a complete resolution at one year follow-up. The authors believe that multilevel laminoplasty rather than laminectomy is the technique of choice as a posterior procedure for extensive lumbar spinal tumors. With this technique, it is possible to obtain a very confortable approach to the dura and intradural content, as well as a perfect replacement of the posterior spinal arch with supporting elements and an optimal reconstruction of the normal spine. Moreover, this method prevents postoperative instability and deformity and avoids the so called post-laminectomy epidural membrane.