GUILHERME CARVALHAL RIBAS
Projetos de Pesquisa
Unidades Organizacionais
LIM/02 - Laboratório de Anatomia Médico-Cirúrgica, Hospital das Clínicas, Faculdade de Medicina
5 resultados
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- Three-dimensional digital projection in neurosurgical education: technical note(2015) MARTINS, Carolina; RIBAS, Eduardo Carvalhal; RHOTON JR., Albert L.; RIBAS, Guilherme CarvalhalThree-dimensional images have become an important tool in teaching surgical anatomy, and its didactic power is enhanced when combined with 3D surgical images and videos. This paper describes the method used by the last author (G.C.R.) since 2002 to project 3D anatomical and surgical images using a computer source. Projecting 3D images requires the superposition of 2 similar but slightly different images of the same object. The set of images, one mimicking the view of the left eye and the other mimicking the view of the right eye, constitute the stereoscopic pair and can be processed using anaglyphic or horizontal-vertical polarization of light for individual use or presentation to larger audiences. Classically, 3D projection could be obtained by using a double set of slides, projected through 2 slide projectors, each of them equipped with complementary filters, shooting over a medium that keeps light polarized (a silver screen) and having the audience wear appropriate glasses. More recently, a digital method of 3D projection has been perfected. In this method, a personal computer is used as the source of the images, which are arranged in a Microsoft Power Point presentation. A beam splitter device is used to connect the computer source to 2 digital, portable projectors. Filters, a silver screen, and glasses are used, similar to the classic method. Among other advantages, this method brings flexibility to 3D presentations by allowing the combination of 3D anatomical and surgical still images and videos. It eliminates the need for using film and film developing, lowering the costs of the process. In using small, powerful digital projectors, this method substitutes for the previous technology, without incurring a loss of quality, and enhances portability.
bookPart Acidente vascular cerebral maligno da artéria cerebral média(2015) RIBAS, Guilherme Carvalhal; FUNCHAL, Bruno; RIBAS, Eduardo Santamaria Carvalhal; GENTIL, André Félix- Head positioning for anterior circulation aneurysms microsurgery(2014) CHADDAD-NETO, Feres; DORIA-NETTO, Hugo Leonardo; CAMPOS-FILHO, Jose Maria de; RIBAS, Eduardo Santamaria Carvalhal; RIBAS, Guilherme Carvalhal; OLIVEIRA, Evandro deObjective: To study the ideal patient's head positioning for the anterior circulation aneurysms microsurgery. Method: We divided the study in two parts. Firstly, 10 fresh cadaveric heads were positioned and dissected in order to ideally expose the anterior circulation aneurysm sites. Afterwards, 110 patients were submitted to anterior circulation aneurysms microsurgery. During the surgery, the patient's head was positioned accordingly to the aneurysm location and the results from the cadaveric study. The effectiveness of the position was noted. Results: We could determine mainly two patterns for head positioning for the anterior circulation aneurysms. Conclusion: The best surgical exposure is related to specific head positions. The proper angle of microscopic view may minimize neurovascular injury and brain retraction.
- Microsurgical anatomy of the central core of the brain(2018) RIBAS, Eduardo Carvalhal; YAGMURLU, Kaan; OLIVEIRA, Evandro de; RIBAS, Guilherme Carvalhal; RHOTON JR., AlbertOBJECTIVE The purpose of this study was to describe in detail the cortical and subcortical anatomy of the central core of the brain, defining its limits, with particular attention to the topography and relationships of the thalamus, basal ganglia, and related white matter pathways and vessels. METHODS The authors studied 19 cerebral hemispheres. The vascular systems of all of the specimens were injected with colored silicone, and the specimens were then frozen for at least 1 month to facilitate identification of individual fiber tracts. The dissections were performed in a stepwise manner, locating each gray matter nucleus and white matter pathway at different depths inside the central core. The course of fiber pathways was also noted in relation to the insular limiting sulci. RESULTS The insular surface is the most superficial aspect of the central core and is divided by a central sulcus into an anterior portion, usually containing 3 short gyri, and a posterior portion, with 2 long gyri. It is bounded by the anterior limiting sulcus, the superior limiting sulcus, and the inferior limiting sulcus. The extreme capsule is directly underneath the insular surface and is composed of short association fibers that extend toward all the opercula. The claustrum lies deep to the extreme capsule, and the external capsule is found medial to it. Three fiber pathways contribute to form both the extreme and external capsules, and they lie in a sequential anteroposterior disposition: the uncinate fascicle, the inferior fronto-occipital fascicle, and claustrocortical fibers. The putamen and the globus pallidus are between the external capsule, laterally, and the internal capsule, medially. The internal capsule is present medial to almost all insular limiting sulci and most of the insular surface, but not to their most anteroinferior portions. This anteroinferior portion of the central core has a more complex anatomy and is distinguished in this paper as the ""anterior perforated substance region."" The caudate nucleus and thalamus lie medial to the internal capsule, as the most medial structures of the central core. While the anterior half of the central core is related to the head of the caudate nucleus, the posterior half is related to the thalamus, and hence to each associated portion of the internal capsule between these structures and the insular surface. The central core stands on top of the brainstem. The brainstem and central core are connected by several white matter pathways and are not separated from each other by any natural division. The authors propose a subdivision of the central core into quadrants and describe each in detail. The functional importance of each structure is highlighted, and surgical approaches are suggested for each quadrant of the central core. CONCLUSIONS As a general rule, the internal capsule and its vascularization should be seen as a parasagittal barrier with great functional importance. This is of particular importance in choosing surgical approaches within this region.
bookPart Monitorização da pressão intracraniana e drenagem ventricular(2016) RIBAS, Eduardo; GENTIL, André Felix; RIBAS, Guilherme Carvalhal