RESUMO
The pial vasculature is the sole source of blood supply to the neocortex. The brain is contained within the skull, a vascularized bone marrow with a unique anatomical connection to the brain meninges. Recent developments in tissue clearing have enabled detailed mapping of the entire pial and calvarial vasculature. However, what are the absolute flow rate values of those vascular networks? This information cannot accurately be retrieved with the commonly used bioimaging methods. Here, we introduce Pia-FLOW, a unique approach based on large-scale transcranial fluorescence localization microscopy, to attain hemodynamic imaging of the whole murine pial and calvarial vasculature at frame rates up to 1,000 Hz and spatial resolution reaching 5.4 µm. Using Pia-FLOW, we provide detailed maps of flow velocity, direction, and vascular diameters which can serve as ground-truth data for further studies, advancing our understanding of brain fluid dynamics. Furthermore, Pia-FLOW revealed that the pial vascular network functions as one unit for robust allocation of blood after stroke.
Assuntos
Conectoma , Hemodinâmica , Pia-Máter , Animais , Camundongos , Hemodinâmica/fisiologia , Pia-Máter/irrigação sanguínea , Circulação Cerebrovascular/fisiologia , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Crânio/diagnóstico por imagem , Crânio/irrigação sanguínea , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/diagnóstico por imagem , Masculino , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: Topographic and blood vessel architecture study of the parietal area and distal regional pool of the superficial temporal artery (STA) to assess the possibility of revascularized cranium vault bone autograft formation. MATERIAL AND METHODS: For the topographic and anatomical study, 30 non-fixed corpses (17 male and 13 female) were selected, the average age of which was 59±5 years. In the anamnesis and catamnesis, there were no indications of trauma or other pathology of the head and neck, including vascular. STA was contrasted with a non-radiocontrast dye (brilliant green) with the introduction of the dye into the STA with preliminary ligation of the frontal branch of the STA. The area of blood supply to soft tissue and bone structures was studied. The angioarchitectonics of the parietal region was studied, the feeding vessel of the studied flap was identified. RESULTS: The obtained anatomical landmarks for the collection of CPFP flap make it possible to form a flap with high accuracy and minimize the morbidity of the donor area.
Assuntos
Artérias Temporais , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Artérias Temporais/transplante , Artérias Temporais/cirurgia , Crânio/cirurgia , Crânio/irrigação sanguínea , Autoenxertos/transplante , Autoenxertos/irrigação sanguínea , Retalhos Cirúrgicos/irrigação sanguínea , Transplante Ósseo/métodos , Osso Parietal/cirurgia , Osso Parietal/irrigação sanguínea , Osso Parietal/transplanteRESUMO
There is increasing interest in how immune cells in the meninges-the membranes that surround the brain and spinal cord-contribute to homeostasis and disease in the central nervous system1,2. The outer layer of the meninges, the dura mater, has recently been described to contain both innate and adaptive immune cells, and functions as a site for B cell development3-6. Here we identify organized lymphoid structures that protect fenestrated vasculature in the dura mater. The most elaborate of these dural-associated lymphoid tissues (DALT) surrounded the rostral-rhinal confluence of the sinuses and included lymphatic vessels. We termed this structure, which interfaces with the skull bone marrow and a comparable venous plexus at the skull base, the rostral-rhinal venolymphatic hub. Immune aggregates were present in DALT during homeostasis and expanded with age or after challenge with systemic or nasal antigens. DALT contain germinal centre B cells and support the generation of somatically mutated, antibody-producing cells in response to a nasal pathogen challenge. Inhibition of lymphocyte entry into the rostral-rhinal hub at the time of nasal viral challenge abrogated the generation of germinal centre B cells and class-switched plasma cells, as did perturbation of B-T cell interactions. These data demonstrate a lymphoid structure around vasculature in the dura mater that can sample antigens and rapidly support humoral immune responses after local pathogen challenge.
Assuntos
Dura-Máter , Imunidade Humoral , Tecido Linfoide , Veias , Administração Intranasal , Antígenos/administração & dosagem , Antígenos/imunologia , Medula Óssea/imunologia , Sistema Nervoso Central/irrigação sanguínea , Sistema Nervoso Central/imunologia , Dura-Máter/irrigação sanguínea , Dura-Máter/imunologia , Centro Germinativo/citologia , Centro Germinativo/imunologia , Vasos Linfáticos/imunologia , Tecido Linfoide/irrigação sanguínea , Tecido Linfoide/imunologia , Plasmócitos/imunologia , Crânio/irrigação sanguínea , Linfócitos T/imunologia , Veias/fisiologia , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Animais , Camundongos , Idoso de 80 Anos ou maisRESUMO
The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis1 to define the anatomy of normal and stress haematopoiesis. In the steady state, across the skeleton, single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels, where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells, which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults, as it was maintained after haemorrhage, systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment, and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis, define the anatomy of normal and stress responses, identify discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncover unprecedented heterogeneity of stress responses across the skeleton.
Assuntos
Hematopoese , Células-Tronco Hematopoéticas , Estresse Fisiológico , Animais , Feminino , Masculino , Camundongos , Envelhecimento/fisiologia , Infecções Bacterianas/patologia , Infecções Bacterianas/fisiopatologia , Vasos Sanguíneos/citologia , Linhagem da Célula , Eritropoese , Fator Estimulador de Colônias de Granulócitos/metabolismo , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Hemorragia/patologia , Hemorragia/fisiopatologia , Linfopoese , Megacariócitos/citologia , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/metabolismo , Mielopoese , Crânio/irrigação sanguínea , Crânio/patologia , Crânio/fisiopatologia , Esterno/irrigação sanguínea , Esterno/citologia , Esterno/metabolismo , Estresse Fisiológico/fisiologia , Tíbia/irrigação sanguínea , Tíbia/citologia , Tíbia/metabolismoRESUMO
The healing of calvarial bone defects is a pressing clinical problem that involves the dynamic interplay between angiogenesis and osteogenesis within the osteogenic niche. Although structural and functional vascular remodeling (i.e., angiogenic evolution) in the osteogenic niche is a crucial modulator of oxygenation, inflammatory and bone precursor cells, most clinical and pre-clinical investigations have been limited to characterizing structural changes in the vasculature and bone. Therefore, we developed a new multimodality imaging approach that for the first time enabled the longitudinal (i.e., over four weeks) and dynamic characterization of multiple in vivo functional parameters in the remodeled vasculature and its effects on de novo osteogenesis, in a preclinical calvarial defect model. We employed multi-wavelength intrinsic optical signal (IOS) imaging to assess microvascular remodeling, intravascular oxygenation (SO2), and osteogenesis; laser speckle contrast (LSC) imaging to assess concomitant changes in blood flow and vascular maturity; and micro-computed tomography (µCT) to validate volumetric changes in calvarial bone. We found that angiogenic evolution was tightly coupled with calvarial bone regeneration and corresponded to distinct phases of bone healing, such as injury, hematoma formation, revascularization, and remodeling. The first three phases occurred during the initial two weeks of bone healing and were characterized by significant in vivo changes in vascular morphology, blood flow, oxygenation, and maturity. Overall, angiogenic evolution preceded osteogenesis, which only plateaued toward the end of bone healing (i.e., four weeks). Collectively, these data indicate the crucial role of angiogenic evolution in osteogenesis. We believe that such multimodality imaging approaches have the potential to inform the design of more efficacious tissue-engineering calvarial defect treatments.
Assuntos
Regeneração Óssea , Crânio , Microtomografia por Raio-X , Crânio/diagnóstico por imagem , Crânio/irrigação sanguínea , Crânio/lesões , Regeneração Óssea/fisiologia , Osteogênese/fisiologia , CicatrizaçãoRESUMO
Cortical visualization is essential to understand the dynamic changes in brain microenvironment under physiopathological conditions. However, the turbid scalp and skull severely limit the imaging depth and resolution. Existing cranial windows require invasive scalp excision and various subsequent skull treatments. Non-invasive in vivo imaging of skull bone marrow, meninges, and cortex through scalp and skull with high resolution yet remains a challenge. In this work, a non-invasive trans-scalp/skull optical clearing imaging window is proposed for cortical and calvarial imaging, which is achieved by applying a novel skin optical clearing reagent. The imaging depth and resolution are greatly enhanced in near infrared imaging and optical coherence tomography imaging. Combining this imaging window with adaptive optics, we achieve the visualization and manipulation of the calvarial and cortical microenvironment through the scalp and skull using two-photon imaging for the first time. Our method provides a well-performed imaging window and paves the way for intravital brain studies with the advantages of easy-operation, convenience and non-invasiveness.
Assuntos
Couro Cabeludo , Crânio , Camundongos , Animais , Couro Cabeludo/diagnóstico por imagem , Crânio/diagnóstico por imagem , Crânio/irrigação sanguínea , Crânio/cirurgia , Encéfalo/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Imagem Óptica/métodos , Neuroimagem/métodosRESUMO
OBJECT: Sinus pericranii (SP) is a rare, benign, extradural venous anomaly whose extracranial connection consists in an enlarged subgaleal drainage composed of a network of thin-walled veins that form a varix on the external table of the skull. In the present series of three patients we present three variantesof SP which have never been described, characterized by an extensive diploic erosion causing a "karstic" effect. METHODS: A systematic review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. A comprehensive search for relevant articles was performed on PubMed from 1992 to 2022 using the following search words: "sinus pericranii". RESULTS: The search produced 77 articles with 137 patients. In all the cases analysed, there were not reported any patients with extensive diploic erosion, namely "karstic" variants. So, the authors present clinical history, neuroimages, treatment strategies and outcome of 3 patients with a "karstic" SP with the aim to describe this clinicradiological entity. CONCLUSIONS: In this study, our group identified a peculiar variant of SP characterized by bony involvement with extensive diploic "karstic" erosion of diploe, with possible tendency to enlarge during time.
Assuntos
Seio Pericrânio , Malformações Vasculares , Criança , Cabeça , Humanos , Seio Pericrânio/cirurgia , Crânio/irrigação sanguínea , Crânio/diagnóstico por imagem , VeiasRESUMO
The current paper is a review of the results attained in the past and current anatomical studies, aimed at understanding the variability and function of the diploic venous system of the human skull. The diploic veins can serve as transit for infections from the scalp to the structures contained within the cranial cavity via the emissary veins, due to their interconnections with the pericranial veins, meningeal veins and dural sinuses. Thereby this clinical aspect has also been discussed.
Assuntos
Crânio , Veias , Humanos , Crânio/irrigação sanguíneaRESUMO
The endocranial structures of the sebecid crocodylomorph Zulmasuchus querejazus (MHNC 6672) from the Lower Paleocene of Bolivia are described in this article. Using computed tomography scanning, the cranial endocast, associated nerves and arteries, endosseous labyrinths, and cranial pneumatization are reconstructed and compared with those of extant and fossil crocodylomorphs, representative of different ecomorphological adaptations. Z. querejazus exhibits an unusual flexure of the brain, pericerebral spines, semicircular canals with a narrow diameter, as well as enlarged pharyngotympanic sinuses. First, those structures allow to estimate the alert head posture and hearing capabilities of Zulmasuchus. Then, functional comparisons are proposed between this purportedly terrestrial taxon, semi-aquatic, and aquatic forms (extant crocodylians, thalattosuchians, and dyrosaurids). The narrow diameter of the semicircular canals but expanded morphology of the endosseous labyrinths and the enlarged pneumatization of the skull compared to other forms indeed tend to indicate a terrestrial lifestyle for Zulmasuchus. Our results highlight the need to gather new data, especially from altirostral forms in order to further our understanding of the evolution of endocranial structures in crocodylomorphs with different ecomorphological adaptations.
Assuntos
Evolução Biológica , Dinossauros/anatomia & histologia , Fósseis/anatomia & histologia , Canais Semicirculares/anatomia & histologia , Crânio/diagnóstico por imagem , Animais , Artérias/anatomia & histologia , Artérias/diagnóstico por imagem , Bolívia , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Vértebras Cervicais/anatomia & histologia , Vértebras Cervicais/diagnóstico por imagem , Nervos Cranianos/anatomia & histologia , Nervos Cranianos/diagnóstico por imagem , Cavidades Cranianas/anatomia & histologia , Cavidades Cranianas/diagnóstico por imagem , Dinossauros/fisiologia , Orelha Interna/anatomia & histologia , Orelha Interna/diagnóstico por imagem , Fósseis/diagnóstico por imagem , Audição , Estilo de Vida , Postura , Canais Semicirculares/diagnóstico por imagem , Crânio/anatomia & histologia , Crânio/irrigação sanguínea , Tomógrafos ComputadorizadosRESUMO
Vascularization is critical for skull development, maintenance, and healing. Yet, there remains a significant knowledge gap in the relationship of blood vessels to cranial skeletal progenitors during these processes. Here, we introduce a quantitative 3D imaging platform to enable the visualization and analysis of high-resolution data sets (>100 GB) throughout the entire murine calvarium. Using this technique, we provide single-cell resolution 3D maps of vessel phenotypes and skeletal progenitors in the frontoparietal cranial bones. Through these high-resolution data sets, we demonstrate that CD31hiEmcnhi vessels are spatially correlated with both Osterix+ and Gli1+ skeletal progenitors during postnatal growth, healing, and stimulated remodeling, and are concentrated at transcortical canals and osteogenic fronts. Interestingly, we find that this relationship is weakened in mice with a conditional knockout of PDGF-BB in TRAP+ osteoclasts, suggesting a potential role for osteoclasts in maintaining the native cranial microvascular environment. Our findings provide a foundational framework for understanding how blood vessels and skeletal progenitors spatially interact in cranial bone, and will enable more targeted studies into the mechanisms of skull disease pathologies and treatments. Additionally, our technique can be readily adapted to study numerous cell types and investigate other elusive phenomena in cranial bone biology.
Assuntos
Neovascularização Fisiológica , Crânio/irrigação sanguínea , Animais , Becaplermina/genética , Becaplermina/metabolismo , Imageamento Tridimensional , Camundongos , Camundongos Endogâmicos C57BL , Microcirculação , Osteoclastos/metabolismo , Crânio/diagnóstico por imagem , Crânio/metabolismoRESUMO
The current study aimed to evaluate the effects of chemokine stromal cell-derived factor (SDF)-1α and platelet-rich plasma (PRP) on bone formation and angiogenesis, and to assess whether SDF-1α and PRP could function synergistically. Four evenly distributed defects (8 mm in diameter) were generated in the calvarial bones of New Zealand white rabbits. All rabbits received four treatment regimens containing autogenous bone particles (AB), SDF-1α, or PRP. AB group presented significantly less bone formation compared with the other three groups 2 and 4 weeks after surgery. The amount of newly formed bone in the AB+PRP+SDF-1α group was similar to that in the AB + SDF-1α group at the 4-week time-point (p = 0.65), and was much greater than that in the AB and AB+PRP group (p < 0.001). Meanwhile, more new blood vessels were formed in the AB+PRP, AB+SDF-1α, and AB+PRP+SDF-1α group versus the AB group. AB+PRP+SDF-1α group showed statistically increased angiogenesis compared with the AB+PRP and AB+SDF-1α groups (both p < 0.05) after treatment for 2 and 4 weeks. These findings indicated that SDF-1α and PRP might exhibit synergistic effects to promote angiogenesis in early bone regeneration.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Quimiocina CXCL12/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Plasma Rico em Plaquetas/fisiologia , Crânio/efeitos dos fármacos , Animais , Transplante Ósseo/métodos , Osteogênese/efeitos dos fármacos , Coelhos , Crânio/irrigação sanguínea , Crânio/patologia , Cicatrização/efeitos dos fármacosRESUMO
Vascularization is an important early indicator of osteogenesis involving biomaterials. Bone repair and new bone formation are associated with extensive neovascularization. Silicon-based biomaterials have attracted widespread attention due to their rapid vascularization. Although calcium phosphate cement (CPC) is a mature substitute for bone, the application of CPC is limited by its slow degradation and insufficient promotion of neovascularization. Calcium silicate (CS) has been shown to stimulate vascular endothelial proliferation. Thus, CS may be added to CPC (CPC-CS) to improve the biocompatibility and neovascularization of CPC. In the early phase of bone repair (the inflammatory phase), macrophages accumulate around the biomaterial and exert both anti- and pro-inflammatory effects. However, the effect of CPC-CS on macrophage polarization is not known, and it is not clear whether the effect on neovascularization is mediated through macrophage polarization. In the present study, we explored whether silicon-mediated macrophage polarization contributes to vascularization by evaluating the CPC-CS-mediated changes in the immuno-environment under different silicate ion contents both in vivo and in vitro. We found that the silicon released from CPC-CS can promote macrophage polarization into the M2 phenotype and rapid endothelial neovascularization during bone repair. Dramatic neovascularization and osteogenesis were observed in mouse calvarial bone defects implanted with CPC-CS containing 60% CS. These findings suggest that CPC-CS is a novel biomaterial that can modulate immune response, promote endothelial proliferation, and facilitate neovascularization and osteogenesis. Thus, CPC-CS shows potential as a bone substitute material.
Assuntos
Cimentos Ósseos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Compostos de Cálcio/farmacologia , Fosfatos de Cálcio/farmacologia , Silicatos/farmacologia , Silício/farmacologia , Crânio/efeitos dos fármacos , Animais , Cimentos Ósseos/química , Compostos de Cálcio/química , Fosfatos de Cálcio/química , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Células RAW 264.7 , Silicatos/química , Silício/química , Crânio/irrigação sanguínea , Crânio/lesõesRESUMO
The transcranial Doppler method (TCD) enables the measurement of cerebral blood flow velocity and detection of emboli by applying an ultrasound probe to the temporal bone window, or the orbital or greater occipital foramina. TCD is widely used for evaluation of cerebral vasospasm after subarachnoid hemorrhage, early detection of patients with arterial stenosis, and the assessment of brain death. However, measurements often become difficult in older women. Among various factors contributing to this problem, we focused on the effect of the diploe in the skull bone on the penetration of ultrasound into the brain. In particular, the effect of the cancellous bone structure in the diploe was investigated. Using a 2D digital bone model, wave propagation through the skull bone was investigated using the finite-difference time-domain (FDTD) method. We fabricated digital bone models with similar structure but different BV/TV (bone volume/total volume) values in the diploe. At a BV/TV of approximately 50-60% (similar to that of older women), the minimum ultrasound amplitude was observed as a result of scattering and multiple reflections in the cancellous diploe. These results suggest that structural changes such as osteoporosis may be one factor hampering TCD measurements.
Assuntos
Encéfalo/patologia , Osso Esponjoso/patologia , Crânio/patologia , Idoso , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Osso Esponjoso/irrigação sanguínea , Osso Esponjoso/diagnóstico por imagem , Circulação Cerebrovascular , Simulação por Computador , Feminino , Humanos , Crânio/irrigação sanguínea , Crânio/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodosRESUMO
SUMMARY: Accessory vessel grooves (AVG), or accessory vessel sulcus, is the name given to grooves seen in the frontal region of the skull. In studies conducted by anthropologists on antiquity skeletons, it is seen that some variations are confused with traumas due to the unknown skeletal morphology. This situation leads to an incorrect evaluation of the socio-economic or health structure of the population. In this study, an accessory vessel grooves research was carried out on the skeletons of the late Roman-early Byzantine population. Studies were conducted on 69 adult human skeletons of known age and sex, and 3 human skeletal skulls whose sex could not be determined. Accessory vessel grooves rate was calculated as 10.54 % in the Spradon ancient population. While there is 10.52 % AVG in female individuals in the population, lower AVG levels have been detected in males compared to females with 9.67 %. There is no significant difference between male and female individuals in terms of AVG. Although the lengths of AVG differ in the right and left frontal, it can be said that there is no difference in direction. Although the relation of AVG variation with high blood pressure is included in the literature, the intense appearance of this structure in the Spradon Population, especially in young individuals, weakens this hypothesis. The literature on the existence of AVG will expand further with the studies to be carried out on ancient Anatolian populations in the following years.
RESUMEN: Surcos de los vasos accesorios (SVA), o canales de vasos accesorios, es el nombre que se les da a los surcos que se ven en la región frontal del cráneo. En los estudios realizados por antropólogos sobre esqueletos de la antigüedad, algunas variaciones se pueden confundir con traumas debido a la morfología esquelética desconocida. Esta situación conduce a una valoración incorrecta de la estructura socioeconómica o sanitaria de la población. En este estudio, se llevó a cabo una investigación de surcos de vasos sanguíneos accesorios en los esqueletos de la población romana tardía y bizantina temprana. Se realizaron estudios en 69 esqueletos humanos adultos de edad y sexo conocidos, y 3 cráneos esqueléticos humanos cuyo sexo no se pudo determinar. La tasa de surcos de vasos accesorios se calculó como 10,54 % en la población antigua de Spradon. Si bien hay un 10,52 % de SVA en las mujeres de la población, se han detectado niveles más bajos de SVA en los hombres en comparación con las mujeres en un 9,67 %. No existe una diferencia significativa entre hombres y mujeres en términos de SVA. Aunque la relación de la variación de SVA con la hipertensión arterial está incluida en la literatura, la importante advertencia de esta estructura en la población de Spradon, particularmente en sujetos jóvenes, debilita esta hipótesis. La literatura sobre la existencia de SVA se ampliará aún más con los estudios que se llevarán a cabo en las antiguas poblaciones de Anatolia en el futuro.
Assuntos
Humanos , Masculino , Feminino , Lactente , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Crânio/irrigação sanguínea , Vasos Sanguíneos/anatomia & histologia , Antropologia , Turquia , Mundo Romano , BizâncioRESUMO
PURPOSE: To date, very few studies have explored the three-dimensional architecture of calvarial diploic venous channels (CDVCs). This study aimed to characterize the three-dimensional architecture of CDVCs using maximum intensity projection (MIP) images based on contrast-enhanced magnetic resonance imaging (MRI). METHODS: A total of 77 patients with intact calvarial hemispheres and underlying dura mater and dural sinuses underwent contrast-enhanced MRI. Among them, we extracted the data of 49 with at least a part of the major CDVC pathways identified on the MIP images for analysis. RESULTS: On serial contrast-enhanced MRI images, the CDVCs were commonly detected as curvilinear structures with inhomogeneous diameters and tributaries, while the MIP images delineated the three-dimensional architecture of the developed CDVC pathways. More than such CDVC pathway was entirely delineated on the right in 67.3% and on the left in 71.4%, most frequently in the frontal and temporal regions, with their connecting sites to the sphenoparietal and superior sagittal sinuses. The morphology, distribution, and course of the identified CDVCs were highly variable. In 55.1%, the CDVCs formed fenestrations that were variable in size, shape, and number. CONCLUSIONS: The developed CDVC pathways may be characterized by morphological variability and fenestrations. Thin-sliced, contrast-enhanced MRI is useful to depict diploic veins, while MIP images allow for better appreciation of the entire course of the developed CDVC pathways. Traumatic and intraoperative disconnection between the dura mater overlying the dural sinuses and the adjacent inner table of the skull can cause epidural venous bleeding.
Assuntos
Cavidades Cranianas/anatomia & histologia , Dura-Máter/irrigação sanguínea , Hematoma Epidural Craniano/etiologia , Crânio/irrigação sanguínea , Adolescente , Adulto , Idoso , Meios de Contraste/administração & dosagem , Cavidades Cranianas/diagnóstico por imagem , Dura-Máter/diagnóstico por imagem , Feminino , Hematoma Epidural Craniano/diagnóstico , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Crânio/diagnóstico por imagem , Adulto JovemRESUMO
Adequate vascularization of scaffolds is a prerequisite for successful repair and regeneration of lost and damaged tissues. It has been suggested that the maturity of engineered vascular capillaries, which is largely determined by the presence of functional perivascular mural cells (or pericytes), plays a vital role in maintaining vessel integrity during tissue repair and regeneration. Here, we investigated the role of pericyte-supported-engineered capillaries in regenerating bone in a critical-size rat calvarial defect model. Prior to implantation, human umbilical vein endothelial cells and human bone marrow stromal cells (hBMSCs) were cocultured in a collagen hydrogel to induce endothelial cell morphogenesis into microcapillaries and hBMSC differentiation into pericytes. Upon implantation into the calvarial bone defects (8 mm), the prevascularized hydrogels showed better bone formation than either untreated controls or defects treated with autologous bone grafts (positive control). Bone formation parameters such as bone volume, coverage area, and vascularity were significantly better in the prevascularized hydrogel group than in the autologous bone group. Our results demonstrate that tissue constructs engineered with pericyte-supported vascular capillaries may approximate the regenerative capacity of autologous bone, despite the absence of osteoinductive or vasculogenic growth factors.
Assuntos
Células Imobilizadas , Hidrogéis , Células-Tronco Mesenquimais , Crânio , Animais , Células Imobilizadas/metabolismo , Células Imobilizadas/patologia , Células Imobilizadas/transplante , Xenoenxertos , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Ratos , Ratos Nus , Crânio/irrigação sanguínea , Crânio/lesões , Crânio/metabolismo , Crânio/patologiaRESUMO
OBJECTIVE: Failure to detect dangerous anatomic vertebral artery anomalies (AVAAs) and dangerous functional vertebral artery anomalies (FVAAs) at the craniovertebral junction (CVJ) in patients with basilar invagination (BI) can result in major complications such as intraoperative vertebral artery injury, brain infarctions, and even death. Iatrogenic vertebral artery injury is a rare but severe complication of cervical spine surgery. We aimed to evaluate dangerous vertebral artery anomalies at the CVJ in patients with BI using computed tomographic angiography (CTA). METHODS: CTA images of 61 BI patients were retrospectively analyzed to evaluate AVAAs and FVAAs at the CVJ. Dangerous AVAAs include a persistent first intersegmental artery (FIA), fenestration of the vertebral artery (FEN), and posterior inferior cerebellar artery with an extradural C1/2 origin (PICA-C1/2). Dangerous FVAAs include a dominant vertebral artery (DVA) and hypoplastic vertebral artery ending in the PICA (HVA-PICA) without joining the basilar artery. RESULTS: Overall, 31 female and 30 male patients (mean age, 42.3 years) were included. The incidences of FIA, FEN, and PICA-C1/2 were 29.5 % (18/61), 3.3 % (2/61), and 3.3 % (2/61), respectively, whereas the incidences of DVA and HVA-PICA were 36.1 % (22/61) and 1.65 % (1/61), respectively. CONCLUSION: Dangerous vertebral artery anomalies at the CVJ have a high incidence in patients with BI. Preoperative CTA is highly recommended in such patients to identify anomalous vertebral arteries and reduce the risk of intraoperative injury.
Assuntos
Artéria Basilar/diagnóstico por imagem , Vértebras Cervicais/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Crânio/diagnóstico por imagem , Artéria Vertebral/anormalidades , Artéria Vertebral/diagnóstico por imagem , Adolescente , Adulto , Idoso , Vértebras Cervicais/irrigação sanguínea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Crânio/irrigação sanguínea , Adulto JovemRESUMO
OBJECTIVE: A high-riding vertebral artery (HRVA) has been defined as a C2 isthmus height of ≤5 mm and/or internal height of ≤2 mm measured 3 mm lateral to the border of the spinal canal. Its reported prevalence has varied widely. If overlooked during the approach for craniocervical fusion, injury to the vertebral arteries can occur, affecting the outcome. The present meta-analysis aimed to provide the pooled prevalence of HRVAs. METHODS: A comprehensive database search was conducted by 3 of us. Peer-reviewed studies that had followed the strict definition for HRVAs and had reported its prevalence were included. The risk of bias was assessed using the anatomical quality assessment tool. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. The pooled prevalence was calculated using a random effects model. RESULTS: The data from 20 studies with 3126 subjects (7496 sides) were analyzed. The overall pooled prevalence of ≥1 HRVA was 25.3% (95% confidence interval [CI], 19.6%-31.5%). The prevalence in those without the most important confounding factor, rheumatoid arthritis (RA), was 20.9% (95% CI, 16.5%-25.8%). Patients with RA had a prevalence of 42.9% (95% CI, 23.8%-63.1%). The difference between the non-RA and RA groups was statistically significant (P < 0.001, test of homogeneity, χ2). No geographical differences were noted (P = 0.20, test of homogeneity, χ2). Among those with HRVA, unilateral HRVA was present in 70.3% (95% CI, 65.2%-75.2%) and bilateral in 29.7% (95% CI, 24.8%-34.8%). No left or right side predilection was found (left, 50.8%; 95% CI, 33.8%-67.6%; right, 49.2%; 95% CI, 32.4%-66.2%). CONCLUSIONS: Craniocervical fusion should be preceded by examination of the vertebral arteries at the level of C2 because the presence of HRVAs is common and might preclude the safe insertion of transarticular or transpedicular screws.
Assuntos
Vértebras Cervicais/cirurgia , Tomada de Decisão Clínica/métodos , Crânio/cirurgia , Fusão Vertebral/métodos , Artéria Vertebral/anormalidades , Vértebras Cervicais/irrigação sanguínea , Vértebras Cervicais/diagnóstico por imagem , Humanos , Prevalência , Crânio/irrigação sanguínea , Crânio/diagnóstico por imagem , Fusão Vertebral/tendências , Resultado do Tratamento , Artéria Vertebral/diagnóstico por imagemRESUMO
OBJECTIVES: Microvascular reconstruction of composite scalp and skull defects requires careful planning of both cranial bone and soft-tissue coverage. The current body of literature has yet to identify a "best practice" approach to achieve these goals. METHODS: A retrospective chart review was performed. Patients with composite defects who underwent combined microvascular surgery of the scalp and skull were included over a 6-year period. Reconstructions were classified by: microvascular flap, cranioplasty, timing of cranioplasty (primary or delayed), and exposure to radiation. RESULTS: Forty-five microvascular flaps were performed for 36 patients. Fasciocutaneous flaps were more likely to experience complications than other microvascular flaps (50.0% versus 8.6%, Pâ=â0.008). Forty of the 50 patients (80%) underwent cranioplasty, including 19 autogenous and 21 alloplastic reconstructions. There were 8 total complications: partial flap loss with implant exposure (nâ=â5), cranioplasty infection (nâ=â2), and wound dehiscence (nâ=â1). Alloplastic implants experienced more frequent complications than autologous reconstructions (33.3% versus 5.3%, Pâ=â0.046). Titanium implants demonstrated the higher rates of complications than other groups (Pâ=â0.014). Titanium implants also had more complications relative to poly-ether-ether-ketone implants (60.0% versus 9.1%, Pâ=â0.024). Immediate alloplastic cranioplasty was associated with a significant increase in complications relative to autogenous reconstruction (54.5% versus 5.5%, Pâ=â0.027), and no significant difference in the delayed group (10% versus 0%, Pâ=â0.740). CONCLUSION: According to authors' knowledge, myofascial flaps yield the lowest complication rate and when possible, autologous cranioplasty is preferred. When defects are too large to accommodate autogenous bone, the authors prefer delayed prefabricated poly-ether-ether-ketone implant reconstruction.