Hippocampal vascularization: Proposal for a new classification.

BACKGROUND: Anatomy of the hippocampal arterial supply is key to successful surgeries in this area. The goal of the current study is to present the results we obtained from our microsurgical dissections of the temporal lobe and to propose a new classification for the hippocampal arteries (HAs). METHODS: Fifty-six brain hemispheres were analyzed. All dissections in this study were made using 3-40× at the surgical microscope. RESULTS: The hippocampal arterial vasculature can be divided into six groups, according to their frequencies: Group A: mixed arterial vasculature originating from the anterior choroidal artery anterior choroidal artery, posterior cerebral artery (PCA), anterior infratemporal artery (AIA), and splenic artery (SA). Group B: Main origin at the temporal branches - main inferotemporal trunk, middle inferotemporal artery, posterior inferotemporal artery, AIA, or main branch of PCA. Group C: AIA as the main branch of the hippocampus. Group D: HAs originating from the main branch of PCA. Group E: A single hippocampal artery with the origin at the main branch of PCA. This single artery covered all of the structure and is named Ushimura's artery. Group F: The hippocampal vessels arose exclusively from the parieto-occipital artery, calcarine artery (CA), and the SA. CONCLUSION: This study proposes a new classification for the hippocampal vascularization, according to the origin of HAs. One of the groups has not yet been described in the literature - in which the HAs arise from the parieto-occipital artery, SA, and CA.

Iron localization in the guinea pig choroid plexus: A light and transmission electron microscopy study.

The role of the choroid plexus (CP) in iron (Fe) homeostasis has been suggested as the main mechanism of Fe uptake and storage in the mammalian central nervous system. Thus, the CP of the lateral and fourth ventricles was studied in guinea pigs with light and electron microscopy using methods including Perls' Prussian blue and Gomori acid phosphatase staining, immunoreactivity for ferritin and transferrin, as well as energy dispersive spectrometry microanalysis. The present study reveals the presence of endogenous Fe in CP epithelial cells. Under light microscopy, Prussian blue staining revealed dark blue precipitates (i.e., Fe3+) with a preferentially perinuclear localization. The Fe was also positive for such granules with similar cellular localization. Ultrastructural analysis demonstrated the presence of dense bodies and siderosomes with molecular ferritin. The spectra obtained by the microanalysis demonstrated emissions for Fe, both in dense bodies and siderosomes. This study suggests that guinea pig CP epithelial cells accumulate Fe in the form of ferritin, possibly in cytoplasmic organelles such as lysosomes.

Influence of the gender on cerebral vascular diameters observed during the magnetic resonance angiographic examination of willis circle

The present study evaluated the calibers and anatomic configurations based on the Magnetic Resonance analysis (MRA), assaying the cerebral vascular territories and sex-linked variations. A randomized sample of 30 angiographic examinations in adult patients of both sexes was obtained and components of the circle of Willis were identified. Branch diameters were measured on a transversal cut 5mm from the vessel origin in a typical angiographic frontal incidence. For the comparative statistical analysis, tests were divided in the groups considering the patients' sex and age. The classical Circle of Willis configuration was oberved in only 15 samples (50%). Greater calibers were observed in the arteries of the posterior circulation and multiple linear regression analysis established that the caliber of the posterior circulation was influenced by an independent variable related to the gender. Additional variations included unilateral and bilateral fetal and hypoplasic Posterior communicating arteries. In the anterior cerebral artery (ACA), the presence of an accessory developed ACA, an ACA giving branches to the distal portion of the two hemispheres and a third median ACA the variants were observed. Gender influenced the variations on internal diameters of posterior circulation vessels, with larger measurements in men.

Vascular corrosion casting technique steps.

The vascular corrosion casting technique produces a replica of vascular beds of normal or pathological tissues. Once associated with scanning electron microscopy (SEM), this technique provides details of the three-dimensional anatomic arrangement of the vascular replica, which is the main advantage of this method. The present study is intended to describe the steps of the vascular corrosion casting technique and the different ways to perform them. them.

[Microsurgical anatomy of the human basal anterior perforated substance]. / Anatomia microcirúgica da substâcia perfurada anterior basal humana.

The anterior perforated substance (APS) is a landmark in the basal forebrain. It has a basal face located above the carotid bifurcation in the subarachnoid space, and an interhemispheric one. It is the site of passage of the arteries to the caudate nucleus, putamen, internal capsule, adjacent areas of the globus pallidus and thalamus. Fifty hemispheres from twenty-five adult cadavers were obtained. The arteries were perfused with colored latex, Batsons resin and gelatin colored with carmine. Using a surgical microscope we have determined the origin, local and number of origin from the parent vessel. The sites of penetration in the mediolateral and anteroposterior direction were also recorded. The anterior communicating artery contribution to the basal APS was reviewed. Significant vascular variations and anastomoses were encountered mainly involving middle cerebral and anterior choroidal arteries. The precise understanding of these vessels has surgical and clinical implications in the management of vascular and tumoral maladies related to the anterior perforated substance.

Anatomia microcirúgica da substâcia perfurada anterior basal humana / Microsurgical anatomy of the human basal anterior perforated substance

A substância perfurada anterior constitui referencial na base do encéfalo. Localizada acima da bifurcação subaracnóidea da artéria carótida interna em sua porção basal e junto à artéria comunicante anterior na face inter-hemisférica, é transfixada por ramos perfurantes dirigidos aos núcleos telencefálicos corticais, cápsula interna e parte do tálamo. Por injeção intravascular de gelatina carminada, resina de Batson e látex, analisamos 50 hemisférios cerebrais humanos adultos de ambos os sexos, sob o microscópio cirúrgico. Objetivamos contribuir para a determinação da origem, número e topografia dos ramos destinados a essa região, seu curso, anastomoses e territórios de penetração. Propusemo-nos também a analisar a contribuição da artéria comunicante anterior à substância perfurada anterior. Foram encontradas variações anatômicas, incluindo anastomoses, envolvendo principalmente a artéria cerebral média e a artéria coróidea anterior. Estes conhecimentos são de interesse clínico-cirúrgico em razão da freqüência de patologias vasculares e tumorais a ela relacionadas.

Anatomy of the caudal cerebral artery on the surface of capybara (Hydrochoerus hydrochaeris) brain

In this study, we examined the distribution of the caudal cerebral artery on the surface of the capybara brain and determined the territory irrigated by this vessel. A total of 68 brain hemispheres from female and male capybaras (Hydrochoerus hydrochaeris) were injected with Latex 603 or Latex Frasca, stained with red and blue pigments and fixed in twenty per cent formalin. The caudal cerebral artery arose from the terminal branch of the basilar artery rostrally to the rrot of the oculomotor nerve. Immediately after its emergence, the caudal cerebral artery gave off the rostral tectal artery in 27,9 per cent of the specimens and then crossed the cerebral peduncles dorsally to the geneculate bodies and to the pulvinar to give off small perforating branches towards these structures. During its course ober the surface of the hippocampal gyrus, the caudal cerebral artery gave off small hippocampal branches dorsally, the caudal choroidal artery rostrally, and a variable number of cortical braches caudally. The terminal branches of the caudal cerebral artery crossed the splenium of the corpus callosum and were distributed on the caudo-medial surface of the brain hemisphere. The territorial limits of the caudal cerebral artery included the thalamus, the rostral colliculum, part of the caudal colliculum, the caudal face of the pyriform lobe, the tentorial surface, the retrosplenic portion of the medial surface, and a narrow area of the dorso-lateral face of the brain hemisphere, along the margins of the dorso longitudinal and transverse fissures of the brain.

Massa radiopaca para repleçäo vascular / Radiopaque injection mass for vascular filling

Apresenta-se uma fórmula com propriedades radiopacas, composta de gelatina, goma arábica, Bariogel e pigmentos, para repleçäo vascular. Discutem-se as vantagens do produto para uso em técnicas de repleçäo vascular em nosso meio