1,720,997 research outputs found
Confocal laser imaging in neurosurgery: A comprehensive review of sodium fluorescein-based CONVIVO preclinical and clinical applications.
Full text linkGiven the established direct correlation that exists among extent of resection and postoperative survival in brain tumors, obtaining complete resections is of primary importance. Apart from the various technological advancements that have been introduced in current clinical practice, histopathological study still remains the gold-standard for definitive diagnosis. Frozen section analysis still represents the most rapid and used intraoperative histopathological method that allows for an intraoperative differential diagnosis. Nevertheless, such technique owes some intrinsic limitations that limit its overall potential in obtaining real-time diagnosis during surgery. In this context, confocal laser technology has been suggested as a promising method to have near real-time intraoperative histological images in neurosurgery, thanks to the results of various studies performed in other non-neurosurgical fields. Still far to be routinely implemented in current neurosurgical practice, pertinent literature is growing quickly, and various reports have recently demonstrated the utility of this technology in both preclinical and clinical settings in identifying brain tumors, microvasculature, and tumor margins, when coupled to the intravenous administration of sodium fluorescein. Specifically in neurosurgery, among different available devices, the ZEISS CONVIVO system probably boasts the most recent and largest number of experimental studies assessing its usefulness, which has been confirmed for identifying brain tumors, offering a diagnosis and distinguishing between healthy and pathologic tissue, and studying brain vessels. The main objective of this systematic review is to present a state-of-the-art summary on sodium fluorescein-based preclinical and clinical applications of the ZEISS CONVIVO in neurosurgery
Combined Multiportal Endoscopic Endonsasal and Transcrinial Approach for Recurnent Tuberculum SeIlae Meningioma: Operative Video
No full textSurgery for anterior cranial base lesions is challenging because tumors often spread from their origin to sinuses, orbits, and middle cranial fossa, resulting in risky surgeries.1,2 To approach such complex diseases, recently combined multiportal approaches have been proposed.3,4 At the best of our knowledge, operative application of a combined endoscopic endonasal and transcranial surgery for complex anterior cranial base lesions has not been described. Therefore a surgical video of such an approach is presented. A 37-year-old woman affected by a huge recurrence of a tuberculum meningioma extended to right orbit presented to our department, complaining of right ocular bulb dislocation with multidirectional limitations in eye movements (Video 1). Given the complexity and localization of the lesion, a combined endoscopic endonasal–transcranial surgery was performed. Such a combined approach, although demanding in terms of the presence of both otolaryngologist and neurosurgeon during the surgery, also requires strong synergy among them and permits them to control anterior cranial base lesions from both specialists' perspectives, simultaneously. In this case, while an endonasal corridor permitted an accurate excision of ethmoidal and medial orbital wall part of the lesion, a bicoronal approach allowed the aggression of the anterior cranial base portion of the tumor, allowing good control of cranial base neurovascular structures, eventually obtaining a gross total resection, without perioperative complications. Furthermore, a combined multiportal approach allows cooperative strategies among the surgeons involved, leading to safer, quicker, and more effective resections with less brain retraction, given the wide angles of views to the lesion that a multiportal approach can offer
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
In Reply: The Coronavirus Disease 2019 Global Pandemic: A Neurosurgical Treatment Algorithm
No full textHuman placenta in vascular neurosurgery training: a comprehensive review of laboratory models, possible exercises, and assessments for skills improvement
No full textIntroduction: Simulation is increasingly recognized as an important tool to enhance neurosurgical education. In this field, especially in neurovascular surgery, human placenta (hPl) is being recognized as a valuable training model because of its abundant availability, ethical acceptance, and analogous vasculature with other vessels of the human body. Nevertheless, although a rising body of literature is witnessing a renovated interest toward this "old" model, to date no comprehensive reviews on the topics are available. Main objective of this paper is to comprehensively review hPl use in neurovascular surgery training, focusing on model preparation, type of possible exercises along with assessment tools which can be used to check for trainees learning. Evidence acquisition: A systematic review of the pertinent literature was performed, following PRISMA guidelines, searching the following key words in "title/abstract" fields in only English-written works: "placenta and neurosurgery." We focused on preclinical works concerning use of hPl models in neurovascular surgery training. We included studies published in the last 40 years, till December 31st, 2023. Evidence synthesis: A total of 950 scientific publications were initially screened, and 23 papers met the inclusion and exclusion criteria. In summary, the chorionic surface of hPl may be used as a neurovascular gym where different exercises can be performed. Placenta models can be produced with or without the use of intravascular dyes and or/pumping systems to resemble a beating-heart vascular system. The three main neurovascular surgical fields where hPl is being considered to be highly simulative are: 1) Sylvian fissure dissection; 2) aneurysm dissection and clipping; 3) bypass training. Considering the simulative purpose, face, content and construct validify of hPl model have been tested and verified by many authors, although still few data are available regarding transfer/predictive validity. Conclusions: This systematic review highlighted the easiness of preparation and availability along with the strong didactical meaning that the use of hPl-based models may have in the field of neurovascular surgery training. In view of current progressive lowering of surgical vascular cases and increasing technical demand related to their management, further studies aimed to assess if this simulator could be able to produce a learning effect and improve performance with continued use are strongly needed
Commentary: Demonstration of Microsurgical Technique and Nuances for the Resection of a Midbrain Tectal Glioma via the Transcollicular Approach: 3-Dimensional Operative Video
No full textEndoscopic Endonasal Odontoidectomy Preserving Atlantoaxial Stability: a Pediatric Case
No full textObjectives We illustrate endoscopic endonasal odontoidectomy for the Chiari-I malformation respecting craniovertebral junction (CVJ) stability.Design Case report of a 12-year-old girl affected by the Chiari-I malformation. Magnetic resonance imaging (MRI) showed tonsillar herniation, basilar invagination, and dental retroversion, causing angulation and compression of the bulbomedullary junction. Patient underwent endoscopic third ventriculostomy ( ETV) with reduction of ventricular size and resolution of gait disturbances, but she complained the Valsalvainduced headaches, hiccup, and dysesthesias in the lower limbs. Endoscopic endonasal odontoidectomy was chosen to decompress the cervicomedullary junction.Setting The research was conducted at University Hospital "Ospedale di Circolo," Department of Neurosurgery at Varese in Italy.Participants Patients were from neurosurgical and ENT (ear, nose, and throat) skull base team.Main Outcome Measures A bilateral paraseptal approach was performed, using a four-hand technique. After resection of posterior edge of the nasal septum, the choana is entered and a rhinopharynx muscle-mucosal flap is dissected subperiosteal and transposed in oral cavity. The CVJ is exposed and, using neuronavigation and neuromonitoring, odontoidectomy is fulfilled until dura is reached, preserving the anterior arch of C1. Reconstruction is obtained suturing the flap previously harvested.Results Postoperative course was unremarkable and the patient experienced improvement of symptoms. Postoperative MRI documented the appearance of tight cerebrospinal fluid (CSF) film anterior to bulbomedullary junction and in retrotonsillar spaces, opening of the bulbomedullary angle, and slight tonsils reduction. No CVJ instability was occurred with any need of posterior fixation. Conclusion Endoscopic endonasal odontoidectomy is a feasible approach for CVJ malformation. In this case, bulbar decompression was achieved preserving CVJ stability and avoiding posterior fixation
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