Comparative Analysis on Surgical Operability and Degree of Exposure of Microsurgical Approaches to Intraforaminal Lumbar Disk Herniations.

BACKGROUND: Intraforaminal lumbar disk herniations (IFDHs) represent a heterogeneous and relatively uncommon disease; their treatment is technically demanding due to the anatomical relationships with nerve roots and vertebral joints. Over time, several approaches have been developed without reaching a consensus about the best treatment strategy. MATERIALS AND METHODS: Authors comparatively analyze surgical operability and exposure in terms of quantitative variables between the different microsurgical approaches to IFDHs, defining the impact of each approach on surgical maneuverability and exposure on specific targets.A comparative microanatomical laboratory investigation was conducted. The operability score (OS) was applied for quantitative analysis of surgical operability. RESULTS: Transarticular and combined translaminar-trans-pars-interarticularis approaches result in providing the best surgical exposure and maneuverability on all targets with surgical controls on both nerve roots, at the expense of a higher risk of iatrogenic instability. Trans-pars-interarticularis approach reaches comparable levels of operability, even limited to the pure foraminal area (lateral compartment); similar findings were recorded for partial facetectomy on the medial compartment. The contralateral interlaminar approach provides good visualization of the foramen without consensual favorable maneuverability, which should be considered the main drawback. CONCLUSIONS: Approach selection has to consider disease location, the possible migration of disk fragments, the degree of nerve root involvement, and risk of iatrogenic instability. According to the findings, authors propose an operative algorithm to tailor the surgical strategy, based both on the precise definition of anatomic boundaries of exposure of each approach and on surgical maneuverability on specific targets.

Posttraumatic extraskeletal chondroma of the posterior neck: A systematic literature review on a rare finding and report of a case.

Extraskeletal chondromas (EC) are uncommon, benign cartilaginous tumours. Most common locations are upper and lower extremities. Location in the neck is extremely rare and reported only within the anterior compartment. Data are limited to just four case reports in the paediatric population. The first case of EC in neck's posterior compartment is described herein. EC present peculiar features on imaging. Aetiology is unclear; however, trauma has been suggested as possible causative mechanism. Treatment of choice is surgical excision; recurrence is not uncommon, but additional removal seems to be resolutive. All cases in literature were asymptomatic, except for one presenting respiratory stridor. The present patient suffered from neck functional limitation and upper limb hypoesthesia. Symptoms improved after surgery in both cases. Imaging follow-up at 6 months in the present case showed no sign of recurrence. ECs are rare, benign lesions. However, they may be preoperatively misinterpreted as more malignant counterparts (both radiologically or histologically), so accurate diagnostic work-up and planning of the surgical procedure are essential.

Primary Gamma Knife Radiosurgery for pineal region tumors: A systematic review and pooled analysis of available literature with histological stratification.

Pineal region tumors (PTs) represent extremely rare pathologies, characterized by highly heterogeneous histological patterns. Most of the available evidence for Gamma Knife radiosurgical (GKSR) treatment of PTs arises from multimodal regimens, including GKSR as an adjuvant modality or as a salvage treatment at recurrence. We aimed to gather existing evidence on the topic and analyze single-patient-level data to address the efficacy and safety of primary GKSR. This is a systematic review of the literature (PubMed, Embase, Cochrane, Science Direct) and pooled analysis of single-patient-level data. A total of 1054 original works were retrieved. After excluding duplicates and irrelevant works, we included 13 papers (n = 64 patients). An additional 12 patients were included from the authors' original series. A total of 76 patients reached the final analysis; 56.5% (n = 43) received a histological diagnosis. Confirmed lesions included pineocytoma WHO grade I (60.5%), pineocytoma WHO grade II (14%), pineoblastoma WHO IV (7%), pineal tumor with intermediate differentiation WHO II/III (4.7%), papillary tumor of pineal region WHO II/III (4.7%), germ cell tumor (2.3%), neurocytoma WHO I (2.3%), astrocytoma WHO II (2.3%) and WHO III (2.3%). Presumptive diagnoses were achieved in the remaining 43.5% (n = 33) of cases and comprised of pineocytoma (9%), germ cell tumor (6%), low-grade glioma (6%), high-grade glioma (3%), meningioma (3%) and undefined in 73%. The mean age at the time of GKSR was 38.7 years and the mean lesional volume was 4.2 ± 4 cc. All patients received GKSR with a mean marginal dose of 14.7 ± 2.1 Gy (50% isodose). At a median 36-month follow-up, local control was achieved in 80.3% of cases. Thirteen patients showed progression after a median time of 14 months. Overall mortality was 13.2%. The median OS was not reached for all included lesions, except high-grade gliomas (8mo). The 3-year OS was 100% for LGG and pineal tumors with intermediate differentiation, 91% for low-grade pineal lesions, 66% for high-grade pineal lesions, 60% for germ cell tumors (GCTs), 50% for HGG, and 82% for undetermined tumors. The 3-year progression-free survival (PFS) was 100% for LGG and pineal intermediate tumors, 86% for low-grade pineal, 66% for high-grade pineal, 33.3% for GCTs, and 0% for HGG. Median PFS was 5 months for HGG and 34 months for GCTs. The radionecrosis rate was 6%, and cystic degeneration was observed in 2%. Ataxia as a presenting symptom strongly predicted mortality (odds ratio [OR] 104, p = .02), while GCTs and HGG histology well predicted PD (OR: 13, p = .04). These results support the efficacy and safety of primary GKSR treatment of PTs. Further studies are needed to validate these results, which highlight the importance of the initial presumptive diagnosis for choosing the best therapeutic strategy.

Anterior selective scalenectomy for periforaminal exposure in the ventral supraclavicular approach.

Aims and Objectives: Route of choice to access cervical paravertebral lesions with foraminal involvement is the anterolateral corridor with its variants. Main limitation of these techniques is represented by the limited surgical access to periforaminal area due to the bulk generated by the anterior scalene muscle (ASM). Over the years, alternative techniques for ASM surgical management have been developed, which are still today a matter of debate. Most popular include ASM scalene complete section (SCS) and ASM medial detachment (SMD). Authors describe an innovative, minimally invasive muscle section technique, the anterior selective scalenectomy (ASS), which reduces the risk of iatrogenic morbidity and optimizes exposure of periforaminal area in anterolateral cervical routes. Materials and Methods: A laboratory investigation was conducted. Technique was applied in a surgical setting, and an illustrative case was reported. Results: ASS is a quick and easy technique to perform. It allows optimization of surgical visibility and control on the periforaminal area in the cervical anterolateral corridor. It respects muscle anatomy and vascularization, favoring functional recovery and management of peri-operative pain; it reduces the risk of morbidity on phrenic nerve and pleura. Considering the minimally invasive nature of the technique, it allows for a slightly more limited exposure compared to traditional techniques while ensuring optimal surgical maneuverability on the target area. Conclusions: ASS represents an effective and safe alternative to traditional ASM section techniques for the exposure of periforaminal area in anterolateral cervical routes. It is indicated in case of lesions with paravertebral development and minimal intraforaminal component in the C3-C6 segment.

Meningioma and Other Meningeal Tumors.

Meningiomas develop from meningothelial cells and approximately account for more than 30 percent of central nervous system (CNS) tumors. They can occur anywhere in the dura, most often intracranially and at dural reflection sites. Half of the cases are usually at parasagittal/falcine and convexity locations; other common sites are sphenoid ridge, suprasellar, posterior fossa, and olfactory groove. The female-to-male ratio is approximately 2 or 3-1, and the median age at diagnosis is 65 years. Meningiomas are generally extremely slow-growing tumors; many are asymptomatic or paucisymptomatic at diagnosis and are discovered incidentally. Clinical manifestations, when present, are influenced by the tumor site and by the time course over which it develops. Meningiomas are divided into three grades. Grade I represents the vast majority of cases; they are considered typical or benign, although their CNS location can still lead to severe morbidity or mortality, resulting in a reported ten-year net survival of over 80%. Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases. They show a tendency for recurrence and malignant degeneration with a relevant increase in tumor cell migration and surrounding tissue infiltration; ten-year net survival is reported over 60%. The anaplastic subtype (WHO III) represents only 1-3% of cases, and it is characterized by a poor prognosis (ten-year net survival of 15%). The treatment of choice for these tumors stands on complete microsurgical resection in case the subsequent morbidities are assumed minimal. On the other hand, and in case the tumor is located in critical regions such as the skull base, or the patient may have accompanied comorbidities, or it is aimed to avoid intensive treatment, some other approaches, including stereotactic radiosurgery and radiotherapy, were recommended as safe and effective choices to be considered as a primary treatment option or complementary to surgery. Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging. A "watchful waiting" strategy appears reasonable for extremely old individuals and those with substantial comorbidities or low-performance status, while there is a reduced threshold for therapeutic intervention for relatively healthy younger individuals due to the expectation that tumor progression will inevitably necessitate proactive treatment. To treat and manage meningioma efficiently, the assessments of both neurosurgeons and radiation oncologists are essential. The possibility of other rarer tumors, including hemangiopericytomas, solitary fibrous tumors, lymphomas, metastases, melanocytic tumors, and fibrous histiocytoma, must be considered when a meningeal lesion is diagnosed, especially because the ideal diagnostic and therapeutic approaches might differ significantly in every tumor type.

Craniopharyngioma in Pediatrics and Adults.

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding ß-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

Brain Tumors Affecting the Orbit Globe and Orbit Tumors Affecting the Brain.

Brain tumors affecting the orbit and orbital tumors affecting the brain are a heterogeneous group of lesions, with histological features, behaviors, diagnostic criteria, and treatments varying from each other. Dermoid cyst and cavernous hemangiomas are considered the most frequent benign lesions, while non-Hodgkin lymphoma is the most common malignant tumor in this region. Sharing the same anatomical region, clinical manifestations of orbital lesions may be often common to different types of lesions. Imaging studies are useful in the differential diagnosis of orbital lesions and the planning of their management. Lesions can be classified into ocular or extra-ocular ones: the latter can be further differentiated into extraconal or intraconal, based on the relationship with the extraocular muscles. Surgical therapy is the treatment of choice for most orbital lesions; however, based on the degree of removal, their histology and extension, other treatments, such as chemotherapy and radiotherapy, are indicated for the management of orbital lesions. In selected cases, chemotherapy and radiotherapy are the primary treatments. This chapter aimed to discuss the orbital anatomy, the clinical manifestations, the clinical testing and the imaging studies for orbital lesions, and the principal pathological entities affecting the orbit together with the principles of orbital surgery.

Efficacy of neoadjuvant stereotactic radiotherapy in brain metastases from solid cancer: a systematic review of literature and meta-analysis.

Neoadjuvant stereotactic radiotherapy (NaSRT) is a novel strategy for brain metastasis (BM) treatment, promising to achieve good local control, improved survival, and low toxicity. This is a systematic review of available literature and meta-analysis of 8 articles eligible for inclusion after searching MEDLINE via PubMed, Web-of-science, Cochrane Wiley, and Embase databases up to March 2023. A total of 484 patients undergoing NaSRT to treat 507 lesions were included. The median age was 60.9 (IQR 57-63) years, with a median tumor volume of 12.1 (IQR 9-14) cm3. The most frequent histology was non-small-cell lung cancer (41.3%), followed by breast (18.8%), and melanoma (14.3%). Lesions had a preferred supratentorial location (77.4%). Most of the studies used a single fraction schedule (91% of patients, n = 440). Treatment parameters were homogeneous and showed a median dose of 18 (IQR 15.5-20.5) Gy at a median of 80% isodose. Surgery was performed after a median of 1.5 (IQR 1-2.4) days and achieved gross-total extent in 94% of cases. Median follow-up was 12.9 (IQR 10-15.7) months. NaSRT showed an overall mortality rate of 58% (95% CI 43-73) at the last follow-up. Actuarial outcomes rates were 60% (95% CI 55-64) for 1-year overall survival (1y-OS), 38% (95% CI 33-43) for 2y-OS, 29% (95% CI 24-34) for 3y-OS; overall 15% (95% CI 11-19) for local failure, 46% (95% CI 37-55) for distant brain failure, 6% (95% CI 3-8) for radionecrosis, and 5% (95% CI 3-8) for leptomeningeal dissemination. The median local progression-free survival time was 10.4 (IQR 9.5-11.4) months, while the median survival without distant failure was 7.4 (IQR 6.9-8) months. The median OS time for the entire cohort was 17 (IQR 14.9-17.9) months. Existing data suggest that NaSRT is effective and safe in the treatment of BMs, achieving good local control on BMs with and low incidence of radionecrosis and leptomeningeal dissemination. Distant control appears limited compared to other radiation regimens.

The carotid sheath route: An option to approach retrocarotid prespinal tumors with paravertebral extension.

Background: The elective route to approach paravertebral lesions growing into the anterolateral lodge of the neck is widely recognized as the prespinal route with its two major variants. Recently, attention has been focused on the possibility of opening the inter-carotid-jugular window in case of reparative surgery for traumatic brachial plexus injury. Aims: For the first time, the authors validate the clinical application of the carotid sheath route in the surgical treatment of paravertebral lesions expanding into the anterolateral lodge of the neck. Methods: A microanatomic study was conducted to collect anthropometric measurements. The technique was illustrated in a clinical setting. Results: The opening of the inter-carotid-jugular surgical window allows additional access to the prevertebral and periforaminal space. It optimizes the operability on the prevertebral compartment, compared to the retro-sternocleidomastoid (SCM) approach, and on the periforaminal compartment, compared to the standard pre-SCM approach. The surgical control of the vertebral artery is comparable to that obtained with the retro-SCM approach, while the control of the esophagotracheal complex and the retroesophageal space is comparable to the pre-SCM approach. The risk profile on the inferior thyroid vessels, recurrent nerve, and sympathetic chain is superimposable to the pre-SCM approach. Conclusions: The carotid sheath route is a safe and effective option to approach prespinal lesions with retrocarotid monolateral paravertebral extension.

Substantially elevated serum glutamate and CSF GOT-1 levels associated with cerebral ischemia and poor neurological outcomes in subarachnoid hemorrhage patients.

Brain injury and cerebral vasospasm during the 14 days after the subarachnoid hemorrhage (SAH) are considered the leading causes of poor outcomes. The primary injury induces a cascade of events, including increased intracranial pressure, cerebral vasospasm and ischemia, glutamate excitotoxicity, and neuronal cell death. The objective of this study was to monitor the time course of glutamate, and associated enzymes, such as glutamate-oxaloacetate transaminase (GOT1), glutamate-pyruvate transaminase (GPT) in cerebrospinal fluid (CSF) and serum, shortly after SAH, and to assess their prognostic value. A total of 74 participants participated in this study: 45 participants with SAH and 29 controls. Serum and CSF were sampled up to 14 days after SAH. SAH participants' clinical and neurological status were assessed at hospitalization, at discharge from the hospital, and 3 months after SAH. Furthermore, a logistic regression analysis was carried out to evaluate the ability of GOT1 and glutamate levels to predict neurological outcomes. Our results demonstrated consistently elevated serum and CSF glutamate levels after SAH. Furthermore, serum glutamate level was significantly higher in patients with cerebral ischemia and poor neurological outcome. CSF GOT1 was significantly higher in patients with uncontrolled intracranial hypertension and cerebral ischemia post-SAH, and independently predicted poor neurological outcomes.

Surgical management of Glioma Grade 4: technical update from the neuro-oncology section of the Italian Society of Neurosurgery (SINch®): a systematic review.

PURPOSE: The extent of resection (EOR) is an independent prognostic factor for overall survival (OS) in adult patients with Glioma Grade 4 (GG4). The aim of the neuro-oncology section of the Italian Society of Neurosurgery (SINch®) was to provide a general overview of the current trends and technical tools to reach this goal. METHODS: A systematic review was performed. The results were divided and ordered, by an expert team of surgeons, to assess the Class of Evidence (CE) and Strength of Recommendation (SR) of perioperative drugs management, imaging, surgery, intraoperative imaging, estimation of EOR, surgery at tumor progression and surgery in elderly patients. RESULTS: A total of 352 studies were identified, including 299 retrospective studies and 53 reviews/meta-analysis. The use of Dexamethasone and the avoidance of prophylaxis with anti-seizure medications reached a CE I and SR A. A preoperative imaging standard protocol was defined with CE II and SR B and usefulness of an early postoperative MRI, with CE II and SR B. The EOR was defined the strongest independent risk factor for both OS and tumor recurrence with CE II and SR B. For intraoperative imaging only the use of 5-ALA reached a CE II and SR B. The estimation of EOR was established to be fundamental in planning postoperative adjuvant treatments with CE II and SR B and the stereotactic image-guided brain biopsy to be the procedure of choice when an extensive surgical resection is not feasible (CE II and SR B). CONCLUSIONS: A growing number of evidences evidence support the role of maximal safe resection as primary OS predictor in GG4 patients. The ongoing development of intraoperative techniques for a precise real-time identification of peritumoral functional pathways enables surgeons to maximize EOR minimizing the post-operative morbidity.

Efficacy of radiotherapy and stereotactic radiosurgery as adjuvant or salvage treatment in atypical and anaplastic (WHO grade II and III) meningiomas: a systematic review and meta-analysis.

The role of radiotherapy (RT) and stereotactic radiosurgery (SRS) as adjuvant or salvage treatment in high-grade meningiomas (HGM) is still debated. Despite advances in modern neuro-oncology, HGM (WHO grade II and III) remains refractory to multimodal therapies. Published reports present aggregated data and are extremely varied in population size, exclusion criteria, selection bias, and inclusion of mixed histologic grades, making it extremely difficult to draw conclusions when taken individually. This current work aims to gather the existing evidence on RT and SRS as adjuvants following surgery or salvage treatment at recurrence after multimodality therapy failure and to conduct a systematic comparison between these two modalities. An extensive systematic literature review and meta-analysis were performed. A total of 42 papers were eligible for final analysis (RT n = 27; SRS n = 15) after searching MEDLINE via PubMed, Web-of-science, Cochrane Wiley, and Embase databases. Adjuvant regimens were addressed in 37 papers (RT n = 26; SRS n = 11); salvage regimens were described in 5 articles (RT n = 1; SRS n = 4). The primary outcomes of the study were the overall recurrence rate and mortality. Other actuarial rates (local and distant control, OS, PFS, and complications) were retrieved and analyzed as secondary outcomes. A total of 2853 patients harboring 3077 HGM were included. The majority were grade II (87%) with a mean pre-radiation volume of 8.7 cc. Adjuvant regimen: 2742 patients (76.4% RT; 23.6% SRS) with an overall grade II/III rate of 6.6/1. Lesions treated adjSRS were more frequently grade III (17 vs 12%, p < 0.001), and received subtotal resection (57 vs 27%, p = 0.001) compared to the RT cohort. AdjSRS cohort had a significantly shorter mean follow-up than adjRT (36.7 vs 50.3 months, p = 0.01). The overall recurrence rate was 38% in adjRT vs 25% in adjSRS (p = 0.01), while mortality did not differ between the groups (20% vs 23%, respectively; p = 0.80). The median time to recurrence was 1.5 times longer in the RT group (p = 0.30). Five-year local control was 55% in adjRT and 26% in adjSRS (p = 0.01), while 5-year OS was 73% and 78% (p = 0.62), and 5-year PFS was 62% and 40% in adjRT and adjSRS (p = 0.008). No difference in the incidence of complications (24% vs 14%, p = 0.53). Salvage regimen: 110 patients (37.3% RT; 62.7% SRS) with a grade II/III rate of 8.6/1. The recurrence rate was 46% in salRT vs 24% in salSRS (p = 0.39), time to recurrence was 1.8 times longer in the salRT group (35 vs 18.5 months, p = 0.74). Mortality was slightly yet not significantly higher in salRT (34% vs 12%, p = 0.54). Data on local and distant control were only available for salSRS. The 5-year OS was 49% and 83% (p = 0.90), and the 5-year PFS was 39% and 50% in salRT and salSRS (p = 0.66), respectively. High-grade meningiomas (WHO grade II and III) receiving adjuvant RT showed a higher overall recurrence rate than meningiomas receiving adjuvant SRS. The adjRT cohort, however, achieved higher 5-year LC and PFS rates, thus suggesting a potentially longer time to recurrence compared to adjSRS patients, who, meanwhile, experienced a significantly shorter follow-up. This result must also consider the higher number of grade III lesions and the smaller extent of resection achieved in the adjSRS group. Overall mortality did not differ between the two groups. No differences in outcome measures were observed in salvage regimens.

Transcortical endoportal subchoroidal endoscope-assisted approach to the third ventricle: from virtual reality to anatomical laboratory.

BACKGROUND: Surgical approaches to the third ventricle (TV) have always represented a technical challenge in neurosurgery. Virtual reality (VR) is attaining increasing relevance in training programs and preoperative planning. The aim of this study is to demonstrate the worthwhile mutual contribution of VR simulations and specimen dissections to develop a new surgical approach to the TV. METHODS: The transcortical endoportal subchoroidal endoscope assisted (TEPSEA) approach was planned and simulated thanks to VR (Surgical Theater©, LLC, Cleveland, OH, USA), and then implemented on cadaver specimens by using the VBAS portal system (Viewsite™ Brain Access System TC Model, Vycor Medical™ Inc., Boca Raton, FL, USA). We assessed anthropometric measurements during VR planning and evaluated surgical operability during anatomical dissections. RESULTS: Surgical field depths measured between 75.6 and 85.3 mm to mammillary bodies and habenular commissure, which were in mean 20.2 mm away. An 18-mm movement was estimated for 15°-posterior tilting of a 70-mm long VBAS. Excellent exposure and maneuverability were achieved within the TV through a 2.47 cm2 portal working area. The 30°-endoscope assistance expanded the access towards the anterior and posterior walls of the TV particularly to the infundibular recess, mammillary bodies, habenular commissure and pineal recess. CONCLUSIONS: We documented the utility of a step-by-step VR planning and simulation followed by anatomical dissections to study surgical approaches to deep brain areas. The TEPSEA exploits the portal system and endoscopic assistance to access the entire TV minimizing cortical and white matter manipulation.

History of Evolution of Posterolateral Approaches to the Thoracic Spine: From Cure of Pott's Disease to Epidural Tumor Resection.

Since the end of the nineteenth century, the wide dissemination of Pott's disease has ignited debates about which should be the ideal route to perform ventrolateral decompression of the dorsal spine in case of paraplegia due to spinal cord compression in tuberculosis spondylitis. It was immediately clear that the optimal approach should be the one minimizing the surgical manipulation on both neural and extraneural structures while optimizing the exposure and surgical maneuverability on the target area. The first attempt was reported by Victor Auguste Menard in 1894, who described, for the first time, a completely different route from traditional laminectomy, called costotransversectomy. The technique was conceived to drain tubercular paravertebral abscesses causing paraplegia without manipulating the spinal cord. Over the following decades, many other routes have been described all over the world, thus demonstrating the wide interest on the topic. Surgical development has been marked by the new technical achievements and by instrumental/technological advancements, until the advent of portal surgery and endoscopy-assisted techniques. In this article, the authors retraced the milestones of this history up to the present days, through a systematic review on the topic.

MIS removal of extraforaminal lumbar spine schwannoma using MAS-TLIF retractor: technical note.

BACKGROUND: To report the use of Nuvasive MAS-TLIF retractor for the removal of lumbar spine schwannomas. METHODS: A 47-year-old man with 1-year history of back pain with progressive left sciatica underwent surgical resection of a left extraforaminal lumbar schwannoma (type IV according to Eden's classification) using the MAS-TLIF retractor. RESULTS: The patient completely recovered from the preoperative symptoms and was discharged three days after surgery. The MRI acquired 6 months postoperatively showed complete tumour removal, with no signs of instability. The MAS-TLIF retractor allows for an optimal paraspinal tissues retraction, improving the area of exposure and the manoeuverability angle. Moreover, the stability of the retraction is guaranteed by the positioning of the two transpedicular screws. Spinal fusion is not necessary because the posterior tension band is not jeopardised. CONCLUSIONS: MAS-TLIF retractor allows for a minimally invasive and safe surgical removal of LSS maximising surgical exposure and avoiding spinal fusion.

Decoding the Heterogeneity of Malignant Gliomas by PET and MRI for Spatial Habitat Analysis of Hypoxia, Perfusion, and Diffusion Imaging: A Preliminary Study.

Background: Tumor heterogeneity poses major clinical challenges in high-grade gliomas (HGGs). Quantitative radiomic analysis with spatial tumor habitat clustering represents an innovative, non-invasive approach to represent and quantify tumor microenvironment heterogeneity. To date, habitat imaging has been applied mainly on conventional magnetic resonance imaging (MRI), although virtually extendible to any imaging modality, including advanced MRI techniques such as perfusion and diffusion MRI as well as positron emission tomography (PET) imaging. Objectives: This study aims to evaluate an innovative PET and MRI approach for assessing hypoxia, perfusion, and tissue diffusion in HGGs and derive a combined map for clustering of intra-tumor heterogeneity. Materials and Methods: Seventeen patients harboring HGGs underwent a pre-operative acquisition of MR perfusion (PWI), Diffusion (dMRI) and 18F-labeled fluoroazomycinarabinoside (18F-FAZA) PET imaging to evaluate tumor vascularization, cellularity, and hypoxia, respectively. Tumor volumes were segmented on fluid-attenuated inversion recovery (FLAIR) and T1 post-contrast images, and voxel-wise clustering of each quantitative imaging map identified eight combined PET and physiologic MRI habitats. Habitats' spatial distribution, quantitative features and histopathological characteristics were analyzed. Results: A highly reproducible distribution pattern of the clusters was observed among different cases, particularly with respect to morphological landmarks as the necrotic core, contrast-enhancing vital tumor, and peritumoral infiltration and edema, providing valuable supplementary information to conventional imaging. A preliminary analysis, performed on stereotactic bioptic samples where exact intracranial coordinates were available, identified a reliable correlation between the expected microenvironment of the different spatial habitats and the actual histopathological features. A trend toward a higher representation of the most aggressive clusters in WHO (World Health Organization) grade IV compared to WHO III was observed. Conclusion: Preliminary findings demonstrated high reproducibility of the PET and MRI hypoxia, perfusion, and tissue diffusion spatial habitat maps and correlation with disease-specific histopathological features.

Local Pterional Advancement Flap: A Minimally Invasive Option to Reconstruct Spheno-Temporal Extracranial Soft Tissues Dehiscences in Fragile Patients.

BACKGROUND: Late-onset, extracranial soft tissues dehiscence in the spheno-temporal region after major neurosurgical procedures might represent a potentially life-threatening complication.Due to surgery-related galeal/pericranial and myofascial temporal atrophy, classical regional flaps are often unavailable, enforcing potential indication for free vascularized flaps.Nevertheless, in elderly multioperated patients, who are not eligible for major surgery, it becomes mandatory to consider less invasive options for reconstruction.Authors describe the application of a reconstructive option for late-onset, pterional soft tissues dehiscence in fragile patients, using a local pterional advancement flap. METHODS: Technique is stepwise described and illustrated in its clinical application. RESULTS: Local pterional advancement flap provides an excellent coverage, being extremely pliable, and flexible in contents and design. Vascular pedicle is independent from distal branches of the superficial temporal artery and provides adequate blood flow. Pedicle length enables a good arc of rotation, which facilitates its transposition. Flap preparation is very easy and minimally time consuming, due to its immediate regional availability and the easy harvesting technique. CONCLUSIONS: Local pterional advancement flap represents an effective option as regional flap for the reconstruction of late-onset, pterional soft tissues dehiscence in fragile patients.

Comparison between extended transsphenoidal and transcranial surgery for craniopharyngioma: focus on hypothalamic function and obesity.

PURPOSE: Patients suffering from craniopharyngiomas currently have good survival rates, but long-term sequelae, such as development of obesity, worsen their quality of life. Optimal treatment is still controversial and changed during the decades, becoming less aggressive. Transcranial (TC) surgery was the first approach to be used, followed by extended transsphenoidal (eTNS) access. This study aims to compare the two approaches in terms of risk of hypothalamic damage leading to obesity. METHODS: This is a monocentric retrospective analysis of post-puberal patients treated for primary craniopharyngioma. Postoperative obesity and percentual postsurgical BMI variation were considered proxy for hypothalamic function and used to fit regression models with basal BMI, type of surgery, tumor volume and hypothalamic involvement (anterior vs. anteroposterior). RESULTS: No difference in radicality was observed between the two approaches; eTNS was more effective in ameliorating visual function but was significantly associated with CSF leaks. The TC approach was associated with a higher incidence of diabetes insipidus. Regression analysis showed only tumor volume and basal BMI resulted as independent predictors for both postoperative obesity (respectively, OR 1.15, P = 0.041, and OR 1.57, P < 0.001) and percentual BMI variation (respectively, + 0.92%, P = 0.005, and - 1.49%, P = 0.001). CONCLUSIONS: Larger lesions portend a higher risk to develop postoperative obesity, independently of hypothalamic involvement. Interestingly, basal BMI is independent of lesional volume and is associated with postoperative obesity, but lesser postoperative BMI variation. The surgical approach does not influence the obesity risk. However, eTNS proves valid in managing large tumors with important hypothalamic invasion.

Hemorrhagic Suprasellar Central Nervous System Embryonal Tumor in an Adult: Uncommon Features of an Extremely Rare Neoplasm.

BACKGROUND: Occurrences of suprasellar central nervous system (CNS) embryonal tumors in adults are extremely rare. Hemorrhagic onset is further uncommon, with only anecdotic cases reported in the literature. The authors describe the case of a 57-year-old man affected by a suprasellar CNS embryonal tumor, with hemorrhagic onset and a unique diffusion pattern along the optic pathways. MATERIAL AND METHODS: A 57-year-old man presenting with acute visual acuity worsening and left homonymous hemianopia was referred to our hospital. Neuroradiologic studies demonstrated an infiltrating, high-grade lesion involving the optic chiasm and right retrochiasmatic pathways with a hemorrhagic area in the ipsilateral pulvinar. RESULTS: The patient underwent microsurgical biopsy. Pathologic assessment confirmed the diagnosis of CNS embryonal tumor, not otherwise specified (NOS) according to the 2016 World Health Organization (WHO) classification of CNS tumors. The patient was referred to a multimodal adjuvant treatment; he eventually died 4 months after surgery. Competent literature has been systematically reviewed in the light of the relevant changes made in the last version of the WHO classification. CONCLUSION: Embryonal tumors should be considered in the differential diagnosis for sellar and suprasellar space-occupying lesions, despite the rarity of the disease and the uncommon features at time of presentation. As per our knowledge, this is the first case ever described of hemorrhagic suprasellar embryonal tumor with a diffusion pattern along white matter fibers. Histogenesis, biomolecular and neuroradiologic features, and classification of embryonal tumors are an open field of research, with considerable implications for the definition of better diagnostic pitfalls and therapeutic regimens.