Boosting teamwork between scrub nurses and neurosurgeons: exploring the value of a role-played hands-on, cadaver-free simulation and systematic review of the literature.

Background: Recently, non-technical skills (NTS) and teamwork in particular have been demonstrated to be essential in many jobs, in business as well as in medical specialties, including plastic, orthopedic, and general surgery. However, NTS and teamwork in neurosurgery have not yet been fully studied. We reviewed the relevant literature and designed a mock surgery to be used as a team-building activity specifically designed for scrub nurses and neurosurgeons. Methods: We conducted a systematic review by searching PubMed (Medline) and CINAHL, including relevant articles in English published until 15 July 2023. Then, we proposed a pilot study consisting of a single-session, hands-on, and cadaver-free activity, based on role play. Scrub nurses were administered the SPLINTS (Scrub Practitioners' List of Intraoperative Non-Technical Skills) rating form as a self-evaluation at baseline and 20-30 days after the simulation. During the experiment, surgeons and scrub nurses role-played as each other, doing exercises including a simulated glioma resection surgery performed on an advanced model of a cerebral tumor (Tumor Box, UpSurgeOn®) under an exoscope. At the end, every participant completed an evaluation questionnaire. Results: A limited number of articles are available on the topic. This study reports one of the first neurosurgical team-building activities in the literature. All the participating scrub nurses and neurosurgeons positively evaluated the simulation developed on a roleplay. The use of a physical simulator seems an added value, as the tactile feedback given by the model further helps to understand the actual surgical job, more than only observing and assisting. The SPLINTS showed a statistically significant improvement not only in "Communication and Teamwork" (p = 0.048) but also in "Situation Awareness" (p = 0.031). Conclusion: Our study suggests that team-building activities may play a role in improving interprofessional teamwork and other NTS in neurosurgery.

Role of sodium fluorescein in pediatric low-grade glioma surgery: an update.

PURPOSE: Complete surgical resection is still the mainstay in the treatment of central nervous system low-grade tumors, eventually resulting curative. The complete surgical removal of these lesions, however, may be difficult in some cases because of their infiltrative nature. Intraoperative adjuncts may be a game changer. Sodium fluorescein (SF) is among the ideal candidates as intraoperative tools to favor the actual recognition of the tumor extension, since it accumulates in areas of altered blood-brain barrier, a typical characteristic of pediatric gliomas, and has a low rate of adverse events. This work proposes an update of previous works about the evaluation of the feasibility and usefulness of a systematic use of SF in a low-grade lesion group of pediatric patients. METHODS: Pediatric patients operated on for a resection or a biopsy of a low-grade glial or glioneuronal lesion (WHO grade I and II) at our Institution between September 2021 and December 2023, with the intraoperative use of sodium fluorescein (SF), were enrolled in the study. We collected pre-operative and postoperative clinical and radiological data, intraoperative findings, and post-operative pathological diagnoses. RESULTS: No adverse events were registered related to the intraoperative use of SF. SF appeared useful for the localization of boundaries of tumors, especially when characterized by a high degree of infiltration or by a deep-seated location, and for the checking of possible tumor remnants at the end of surgery. A good tumor-to-healthy tissue contrast was registered when tumor visualization was in a range between 1 to 2 h and 30 min after SF injection. Possible "false positives" due to intraoperative vascular wall injury and clearance of SF from both tumor and healthy tissue were observed in some cases and still remain open issues. CONCLUSIONS: SF is a feasible and safe intraoperative adjunct tool in the surgical removal of pediatric low-grade tumors. SF may show its usefulness especially in selected cases, such as deep-seated lesions and infiltrating tumors. Its safety profile, user-friendly management, and potential utility in both tumor resections and neuronavigated biopsies favor its wider use in the surgical treatment of pediatric low-grade tumors.

Exoscopic microneurosurgery in pediatric brain tumors: an ideal tool for complex and peculiar anatomo-topographic scenarios?

PURPOSE: Since its introduction in the 1950s, the microsurgical paradigm has revolutionized neurosurgery. New technologies have been introduced over the years trying to overcome limits of the classical operating microscope. The recently developed 3D exoscopes represent a potential new paradigm for micro-neurosurgery. We analyzed our own experience with a 4 K-3D exoscope in a series of pediatric brain tumors to verify its advantages and limitations in comparison to the operating microscope and in light of the literature. METHODS: Twenty-five pediatric patients with brain tumors underwent surgery at our Institute; the population has been analyzed and described. A score to evaluate the exoscopes and compare it to the operating microscope was considered and postoperatively applied to each single case. RESULTS: The exoscope appears to be at least comparable to the operating microscope (OM) in all analyzed aspects. In the case of deep-seated or fourth ventricle tumors, the exoscope seems to be superior to the microscope. A surgeon-dependent learning curve is necessary for neurosurgeons to be confident with the exoscope. CONCLUSION: Exoscopes appear to be as safe and effective as operating microscopes in pediatric neuro-oncological surgery. They have some advantages that make them superior to microscopes, particularly regarding surgeon ergonomics and fatigue, visual field qualities, and higher choice of intraoperative viewing angles.

Craniopagus: a proposed nursing care protocol.

Craniopagus is a rare condition in which the skulls of conjoined twins, and the neurovascular structures in their skulls, are incompletely separated. Separation surgery is complex and requires a range of skills and expertise, including from all the nursing teams involved. A multidisciplinary group of professionals in a tertiary paediatric care setting in Italy developed a comprehensive protocol for the nursing care of craniopagus twins in hospital, informed by the findings of a literature review and the expertise of its members. The protocol was applied to the management of a pair of craniopagus twins who successfully underwent separation surgery at the authors' hospital. The protocol describes the crucial role of nurses in the care of craniopagus twins and their families before, during and after separation surgery.

Surgical Complexity and Complications: The Need for a Common Language.

BACKGROUND: Quality measurement and outcome assessment have recently caught an attention of the neurosurgical community, but lack of standardized definitions and methodology significantly complicates these tasks. OBJECTIVE: To identify a uniform definition of neurosurgical complications, to classify them according to etiology, and to evaluate them comprehensively in cases of intracranial tumor removal in order to establish a new, easy, and practical grading system capable of predicting the risk of postoperative clinical worsening of the patient condition. METHODS: A retrospective analysis was conducted on all elective surgeries directed at removal of intracranial tumor in the authors' institution during 2-year study period. All sociodemographic, clinical, and surgical factors were extracted from prospectively compiled comprehensive patient registry. Data on all complications, defined as any deviation from the ideal postoperative course occurring within 30 days of the procedure, were collected with consideration of the required treatment and etiology. A logistic regression model was created for identification of independent factors associated with worsening of the Karnofsky Performance Scale (KPS) score at discharge after surgery in comparison with preoperative period. For each identified statistically significant independent predictor of the postoperative worsening, corresponding score was defined, and grading system, subsequently named Milan Complexity Scale (MCS), was formed. RESULTS: Overall, 746 cases of surgeries for removal of intracranial tumor were analyzed. Postoperative complications of any kind were observed in 311 patients (41.7%). In 223 cases (29.9%), worsening of the KPS score at the time of discharge in comparison with preoperative period was noted. It was independently associated with 5 predictive factors-major brain vessel manipulation, surgery in the posterior fossa, cranial nerve manipulation, surgery in the eloquent area, tumor size >4 cm-which comprised MCS with a range of the total score from 0 to 8 (higher score indicates more complex clinical situations). Patients who demonstrated KPS worsening after surgery had significantly higher total MCS scores in comparison with individuals whose clinical status at discharge was improved or unchanged (3.24 ± 1.55 versus 1.47 ± 1.58; P < 0.001). CONCLUSION: It is reasonable to define neurosurgical complication as any deviation from the ideal postoperative course occurring within 30 days of the procedure. Suggested MCS allows for standardized assessment of surgical complexity before intervention and for estimating the risk of clinical worsening after removal of intracranial tumor. Collection of data on surgical complexity, occurrence of complications, and postoperative outcomes, using standardized prospectively maintained comprehensive patient registries seems very important for quality measurement and should be attained in all neurosurgical centers.

Is Advanced Age a Factor That Influences the Clinical Outcome of Single- or Double-Level MIS-TLIF? A Single-Center Study with a Minimum Two-Year Follow-Up on 103 Consecutive Cases.

As life expectancy rises, more elderly people undergo spinal fusion surgery to treat lumbar degenerative diseases. The MIS-TLIF technique, which minimizes soft tissue manipulation, is a promising fusion technique for frailer patients. The aim of this study was to investigate if older age is a significant factor in the clinical outcome of single- or double-level MIS-TLIF. A cross-sectional study was conducted on 103 consecutive patients. Data were compared between younger (<65 y.o.) and older (≥65 y.o.) patients. We observed no significant differences between baseline characteristics of the two groups apart from the frequency of disk space treated, with a relative predominance of L3-L4 space treated in the elderly (10% vs. 28%, p = 0.01) and L5-S1 space in younger patients (36% vs. 5%, p = 0.006). There was no significant difference in complication rate, surgical satisfaction, EQ 5D-5L, or Oswestry Disability Index (ODI) global or specific scores, with the exception of the EQ 5D-5L "mobility" score, where older patients fared worse (1.8 ± 1.1 vs. 2.3 ± 1.4; p = 0.05). The minimal invasiveness of the surgical technique, age-related specific outcome expectations, and biomechanical issues are all potential factors influencing the lack of age group differences in outcome scores.

Focus session on sodium fluorescein in pediatric oncological neurosurgery.

Many tools and techniques have been developed to obtain maximal safe tumoral resection in neurosurgery. Fluorescent dyes, including sodium fluorescein, have become also part of this armamentarium to localize the lesion and its boundaries peroperatively. Considering its alleged safety profile and its ability to diffuse in areas of altered blood-brain barrier, a typical characteristic of a number of both benign and malignant pediatric tumors, sodium fluorescein may appear an ideal candidate as intraoperative adjunct in pediatric neurosurgery. Nevertheless, a definitive role of this dye in children has not been established yet, and the reports on the pediatric population remain scarce. For this reason, we propose focusing on the use of sodium fluorescein in pediatric oncological neurosurgery by collecting articles reporting the result of the application of the technique in the management of intracranial pediatric tumors.

Sodium fluorescein in pediatric neurosurgery: a systematic review with technical considerations and future perspectives.

BACKGROUND: Sodium fluorescein (SF) is routinely used in several centers as a valid intraoperative adjunct in adult oncological neurosurgery. Its use in pediatric neurosurgery is increasing, although its role is not yet well-defined in children. We reviewed the current literature in order to evaluate the use of SF in children with CNS and PNS lesions. METHODS: For this systematic review, we searched PubMed, Scopus, and Embase databases, and forward and backward citations for studies published between database inception and July 31st, 2022. We included any article type or congress abstract adding at least a new case, without restrictions of language or publication status, concerning the use of SF in neurosurgical procedures in patients under 18 years of age. We excluded studies concerning purely vascular cases and cerebrospinal fluid leaks. RESULTS: Of 4094 records identified, 19 articles were eligible and included for further analysis. As per July 31st, 2022, at least 119 patients aged from 11 months to 17.9 years underwent surgery with SF. No serious adverse events were reported. A large variety of tumor types was operated, in most cases resected under the specific YELLOW 560 nm filter after a low-dose SF injection (2-5 mg/kg) at the end of anesthesia induction. SF was reported particularly useful in gangliogliomas and pilocytic astrocytomas. DISCUSSION/CONCLUSION: Given its easy-to-use profile, low cost, and safety, SF seems to be a feasible and valid adjunct in the pediatric population when aiming at individuating a biopsy target or maximizing extent of resection, particularly in some tumor types. Further studies are required to strengthen the evidence on its impact on outcomes.

Sodium fluorescein in pediatric oncological neurosurgery: a pilot study on 50 children.

BACKGROUND: Sodium fluorescein (SF) is currently considered a valid intraoperative adjunct in the resection of high-grade brain lesions in adults. Experiences in pediatric groups and in low-grade gliomas and other low-grade lesions are still limited in literature, and subjective evaluation of fluorescence is still a limitation. MATERIAL AND METHODS: This study retrospectively reviewed all patients with brain or spine lesions operated on from September 2021 to July 2022 in the Pediatric Neurosurgery Unit of Hôpital Femme Mère Enfant, Lyon, who had received 5 mg/kg of 10%. Surgery was performed using a YELLOW560 filter at crucial times. At the end of surgery, the first operator completed a questionnaire, including his opinion on whether SF had been useful in tumor resection, recorded as a binary variable. Post hoc, surgical images were reviewed using ImageJ, an open-source Java image processing platform. In order to compare independent discrete variables, we applied the Student's t test, and we applied the Chi-square or Fisher exact test for binary variables. A threshold of p < 0.05 was set for statistical significance. RESULTS: We included 50 pediatric patients (0.2-17.6 years old). Forty/50 lesions showed SF uptake (80%). The differentiation between healthy and affected tissue, thanks to SF, subjectively evaluated by the surgeon, had as objective counterpart the statistically significant higher brightness of green in lesions, registered by the software (p < 0.001). SF overall allowed a good differentiation in 33/50 lesions, and overall utility of SF has been noted in 67% of them. When specifically considering gliomas, overall utility reached 75%. CONCLUSION: SF is a feasible, safe, and useful intraoperative adjunct in pediatric neurosurgery. In particular, it seems to have a promising role in some low-grade infiltrating glial tumors. The subjective evaluation of fluorescence seems to be reliable with respect to image analyses software.

Pediatric Low-Grade Glioma Surgery with Sodium Fluorescein: Efficient Localization for Removal and Association with Intraoperative Pathological Sampling.

Low-grade gliomas are among the most common CNS lesions in pediatrics and surgery is often the first-line treatment. Intraoperative tools have been developed to maximize the results of surgery, and in particular dyes such as sodium fluorescein (SF) have been investigated in high-grade adult lesions. The use of SF in pediatric low-grade gliomas is still unclear. We retrospectively reviewed 22 pediatric CNS low-grade gliomas operated on with SF from September 2021 to October 2022. A total of 86% of lesions showed SF uptake, which was helpful intraoperatively (confirmation of initial localization of the tumor, or identification of tumor remnants) in 74% of them. The intraoperative fluorescence seems associated with gadolinium enhancement at the preoperative MRI. Interestingly, the extemporaneous pathological sampling (EPS) was informative in every case showing SF uptake, whereas in cases without SF uptake, the EPS was non-informative, although the tissue was later confirmed as pathological. These findings highlight the interest of SF for perioperative diagnosis of tumor tissue and may suggest in which cases the differentiation of tumor-healthy tissue could be especially blurred, posing difficulties for the pathologist.

Is Gender a Factor Affecting Long-Term Heterotopic Ossification Incidence After Single-Level Cervical Disc Arthroplasty?

BACKGROUND: Cervical disc diseases have been treated by cervical disc arthroplasty (CDA). Nevertheless, some patients will experience a mobility failure in their cervical prostheses over time because of heterotopic ossification. The aim of this study was to investigate the role of gender in long-term outcomes after CDA. METHODS: A retrospective, single-center study of patients who underwent single-level CDA with a BRYAN Cervical Disc prosthesis was performed, including a narrative review about gender differences in both structural and biomechanical features of the cervical spine. RESULTS: Study patients (14 men, 30 women) had an average follow-up of 9.8 ± 3.2 years. Significant differences emerged between genders for specific items in Neck Disability Index preoperative evaluation, with women reporting worse pain scores (P = 0.05). After stratification by age, we found a higher preoperative overall Neck Disability Index score for female patients <36 years of age (P = 0.03). In an intergender, body mass index-specific comparison, we also found a significant difference in Neck Disability Index preoperative score with normal-weight male patients faring worse than overweight male patients (P = 0.05). At a radiological level, we found a tendency toward a higher heterotopic ossification incidence in male patients (62% in men, 17% in women, P = 0.06). The female cervical spine has distinctive features, including bone structure, muscular action, soft tissue response, and genetic and epigenetic response to osteoarthritis. CONCLUSIONS: The incidence of mobility failure in our series of single-level CDA was lower in female patients. Several gender-specific factors both in static and in dynamic features may play a significant role in spinal pathology and CDA long-term radiological outcome.

Posterior fossa syndrome in a population of children and young adults with medulloblastoma: a retrospective, multicenter Italian study on incidence and pathophysiology in a histologically homogeneous and consecutive series of 136 patients.

INTRODUCTION: Posterior fossa syndrome (PFS) is a set of debilitating complications that can occur after surgery for posterior fossa tumors. This study aimed to assess the preoperative radiological and surgical risk factors for the onset of PFS in a histologically homogeneous population of children with medulloblastoma and compare it to a similar population of young adults. METHODS: Included patients underwent posterior fossa surgery for medulloblastoma at 11 Italian neurosurgical wards (2003-2019) and were referred to Fondazione IRCCS Istituto Nazionale dei Tumori in Milan (INT) for postoperative treatments. We collected patients' pre- and post-operative clinical, surgical and radiological data from the INT charts. To compare the distribution of variables, we used the Mann-Whitney and Fisher tests for continuous and categorical variables, respectively. RESULTS: 136 patients (109 children and 27 young adults) were included in the study. Among children, 29 (27%) developed PFS, and all of them had tumors at midline site with invasion of the fourth ventricle. Radiological evidence of involvement of the right superior (39% versus 12%; p = 0.011) or middle cerebellar peduncles (52% versus 18%; p = 0.002) seemed more common in children who developed PFS. Young adults showed an expected lower incidence of PFS (4 out of 27; 15%), that may be due to anatomical, physiological and oncological elements. CONCLUSIONS: This study confirmed some factors known to be associated with PFS onset and shed light on other debated issues. Our findings enhance an already hypothesized role of cerebellar language lateralization. The analysis of a population of young adults may shed more light on the often-neglected existence of PFS in non-pediatric patients.

Cervicomedullary Gliomas in Pediatric Age: A Systematic Review of the Literature and Tertiary Care Center Experience.

INTRODUCTION: Cervicomedullary gliomas (CMGs) are usually low-grade tumors often found in the pediatric age. Histological findings, treatments, and classification have been much the same for 40 years, although histological and molecular classifications have largely been developed for other pediatric CNS tumors. The management and treatment of pediatric CMG are still conducted by many authors according to their anatomical location and characteristics, independently from histology. METHODS: We conducted a literature review in PubMed (Medline) to identify relevant contributions about pediatric CMG published until December 31, 2021. We also analyzed a series of 10 patients with CMG treated from 2006 to 2021 at IRCCS Istituto Nazionale dei Tumori. The aim of the present review was to see whether and how the diagnosis, treatment, and classification of CMGs in children have developed over time, especially in the context of molecular advancements, and to analyze our single-center experience in the last 15 years. RESULTS: Thirty articles have been included in the review. Articles have been divided into two historical periods (1981-2000 and 2001-2021) and data from different series were analyzed to see how much the management and treatment of pediatric CMG have changed during years. Analysis of our series of 10 patients affected by CMG was also performed to compare it with the literature. DISCUSSION: Management and classification of CMG in children have not dramatically changed during years. However, new insight from molecular diagnostics and target therapies and the development of radiological, neurophysiological, and radiotherapy techniques have updated treatment modalities in the last 20 years. Treatment modalities and their innovations have been reviewed and discussed. Further studies are needed to standardize and customize treatment protocols for these tumors.

Contrast-induced encephalopathy and permanent neurological deficit: A case report and literature review.

BACKGROUND: Contrast-induced encephalopathy (CIE) is a rare condition that occurs after intravenous or intra-arterial contrast agent administration. Patients generally show different ranges of neurological deficits, which generally resolve themselves spontaneously within 24-48 h or in rare cases within 2 weeks. CASE DESCRIPTION: We report a case of CIE in a 54-year-old woman during retreatment for recanalization of communicating anterior artery aneurysm and with no history of allergic reaction to contrast agent. After the procedure, the patient developed right hemiplegia and complete aphasia; an MRI performed at 6 days excluded any signs of new ischemia and revealed a hyperintense signal on FLAIR sequences in the left cortical precentral gyrus corresponding to a hyperintense signal on DWI, suggesting a vasogenic edema. After 6 months, she clinically improved even if her previous neurological status was never restored while radiological findings did not change. CONCLUSION: According to the literature, many risk factors may play a role in the pathogenesis of CIE: we hypothesized that, among all of them, chronic hypertension and previous cerebral ischemic lesions were the most important in our case. Further studies are necessary to find the correlation between possible risk factors and neurotoxicity.

Confocal Laser Microscopy in Neurosurgery: State of the Art of Actual Clinical Applications.

Achievement of complete resections is of utmost importance in brain tumor surgery, due to the established correlation among extent of resection and postoperative survival. Various tools have recently been included in current clinical practice aiming to more complete resections, such as neuronavigation and fluorescent-aided techniques, histopathological analysis still remains the gold-standard for diagnosis, with frozen section as the most used, rapid and precise intraoperative histopathological method that permits an intraoperative differential diagnosis. Unfortunately, due to the various limitations linked to this technique, it is still unsatisfactorily for obtaining real-time intraoperative diagnosis. Confocal laser technology has been recently suggested as a promising method to obtain near real-time intraoperative histological data in neurosurgery, due to its established use in other non-neurosurgical fields. Still far to be widely implemented in current neurosurgical clinical practice, this technology was initially studied in preclinical experiences confirming its utility in identifying brain tumors, microvasculature and tumor margins. Hence, ex vivo and in vivo clinical studies evaluated the possibility with this technology of identifying and classifying brain neoplasms, discerning between normal and pathologic tissue, showing very promising results. This systematic review has the main objective of presenting a state-of-the-art summary on actual clinical applications of confocal laser imaging in neurosurgical practice.

Perspectives on (A)symmetry of Arcuate Fasciculus. A Short Review About Anatomy, Tractography and TMS for Arcuate Fasciculus Reconstruction in Planning Surgery for Gliomas in Language Areas.

Gliomas are brain tumors that are treated with surgical resection. Prognosis is influenced by the extent of resection and postoperative neurological status. As consequence, given the extreme interindividual and interhemispheric variability of subcortical white matter (WM) surgical planning requires to be patient's tailored. According to the "connectionist model," there is a huge variability among both cortical areas and subcortical WM in all human beings, and it is known that brain is able to reorganize itself and to adapt to WM lesions. Brain magnetic resonance imaging diffusion tensor imaging (DTI) tractography allows visualization of WM bundles. Nowadays DTI tractography is widely available in the clinical setting for presurgical planning. Arcuate fasciculus (AF) is a long WM bundle that connects the Broca's and Wernicke's regions with a complex anatomical architecture and important role in language functions. Thus, its preservation is important for the postoperative outcome, and DTI tractography is usually performed for planning surgery within the language-dominant hemisphere. High variability among individuals and an asymmetrical pattern has been reported for this WM bundle. However, the functional relevance of AF in the contralateral non-dominant hemisphere in case of tumoral or surgical lesion of the language-dominant AF is unclear. This review focuses on AF anatomy with special attention to its asymmetry in both normal and pathological conditions and how it may be explored with preoperative tools for planning surgery on gliomas in language areas. Based on the findings available in literature, we finally speculate about the potential role of preoperative evaluation of the WM contralateral to the surgical site.

Fluorescent tracers in neurosurgical procedures: a European survey.

BACKGROUND: In recent years several techniques have been proposed with the aim of improving tumors visualization and extent of resection and, among them, the use of photosensitive dyes is gaining great interest. Regarding the application of the two most used dyes, 5-aminolevulinic acid (5-ALA) and sodium fluorescein (SF), there is still a lack of shared and established protocols among different centers. The main objective of the present study was to evaluate the current practice of fluorescence-guided techniques in neuro-oncological surgery in Europe. METHODS: An online questionnaire consisting of 33 questions was completed by 136 European Association of Neurosurgical Societies neurosurgeons. Responses were entered into a database and subsequently analyzed. RESULTS: Data were analyzed from 136 out of 1476 active European neurosurgeons which had been contacted, with a 9,2% response rate. Based on the data from the questionnaire, Germany was the most responsive country (15% of the total respondents) and the main indication for 5-ALA and SF utilization were high-grade gliomas. 5-ALA was mainly used as defined in Gliolan® datasheet, while SF as off-label technique with a 5 mg/kg dose of injection at the end of patient intubation. Both the dyes were mainly used in adult population, more frequently by neurosurgeons with less-than 20 cases per year expertise. Mean price per patient were 817,6 € and 7,7 € for 5-ALA and SF, respectively. CONCLUSIONS: 5-ALA acid is still the preferred and more established fluorescent dye used during high-grade gliomas resection, with SF as a gaining-attention, really cheaper and more ductile alternative.

Role of aquaporins in hydrocephalus: what do we know and where do we stand? A systematic review.

INTRODUCTION: Glymphatic fluid circulation may be considered the lymphatic system of the brain and the main role of such system seems to be played by aquaporins (AQPs), a family of proteins which regulates water exchange, in particular AQP4 and 1. Alterations of glymphatic fluid circulation through AQPs variations are now emerging as central elements in the pathophysiology of different brain conditions, like hydrocephalus. This systematic review provides an insight about the role of AQPs in hydrocephalus establishment and compensation, investigating their possible role as diagnostic tools or therapeutic targets. METHODS: PubMed database was screened searching for the relevant existing literature in English language published until February 29th 2020, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. RESULTS: A total of 40 articles met the inclusion criteria for our systematic analysis. AQP4 resulted the most studied water channel, followed by AQP1. The changes in cerebrospinal fluid (CSF), brain parenchyma and choroid plexus (CP) in different hydrocephalus type were analyzed. Moreover, important pharmacological interactions regarding AQP and molecules or conditions were discussed. A very interesting result is the general consensus on increase of AQP4 in hydrocephalic patients, unless in patients suffering from idiopathic normal pressure hydrocephalus, where AQP4 shows a tendency in reduction. CONCLUSION: AQP seem to play a central role in the pathophysiology of hydrocephalus and in its compensation mechanisms. Further studies are required to definitively establish their precise roles and their quantitative changes to allow their utilization as diagnostic tools or therapeutic targets.

Lighting Up the Tumor-Fluorescein-Guided Resection of Gangliogliomas.

(1) Background: Gangliogliomas comprise a small number of brain tumors. They usually present as World Health Organization (WHO) grade I, and they delineate on gadolinium-enhanced MRI; the surgical goal is wide radical resection, and the course thereafter is usually benign. Fluorescein sodium (FL) tends to accumulate in areas with altered blood-brain barrier (BBB). Thus far, the results provided by prospective and retrospective studies show that the utilization of this fluorophore may be associated with better visualization and improvement of resection for several tumors of the central nervous system. In this study, we retrospectively studied the effect of fluorescein sodium on visualization and resection of gangliogliomas. (2) Methods: Surgical databases in three neurosurgical departments (Regensburg University Hospital; Besta Institute, Milano, Italy; and Liv Hospital, Istanbul, Turkey), with approval by the local ethics committee, were retrospectively reviewed to find gangliogliomas surgically removed by a fluorescein-guided technique by the aid of a dedicated filter on the surgical microscope from April 2014 to February 2020. Eighteen patients (13 women, 5 men; mean age 22.9 years, range 3 to 78 years) underwent surgical treatment for gangliogliomas during 19 operations. Fluorescein was intravenously injected (5 mg/kg) after general anesthesia induction. Tumors were removed using a microsurgical technique with the YELLOW 560 Filter (YE560) (KINEVO/PENTERO 900, Carl Zeiss Meditec, Oberkochen, Germany). (3) Results: No side effects related to fluorescein occurred. In all tumors, contrast enhancement on preoperative MRI correlated with bright yellow fluorescence during the surgical procedure (17 gangliogliomas WHO grade I, 1 ganglioglioma WHO grade II). Fluorescein was considered helpful by the operating surgeon in distinguishing tumors from viable tissue in all cases (100%). Biopsy was intended in two operations, and subtotal resection was intended in one operation. In all other operations considered preoperatively eligible, gross total resection (GTR) was achieved in 12 out of 16 (75%) instances. (4) Conclusions: The use of FL and YE560 is a readily available method for safe fluorescence-guided tumor resection, possibly visualizing tumor margins intraoperatively similar to contrast enhancement in T1-weighted MRI. Our data suggested a positive effect of fluorescein-guided surgery on intraoperative visualization and extent of resection during resection of gangliogliomas.