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1.
Adv Exp Med Biol ; 1232: 299-306, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31893424

RESUMEN

Hypoxic ischemic encephalopathy (HIE) is a significant cause of death and neurological disability in newborns. Therapeutic hypothermia at 33.5 °C is one of the most common treatments in HIE and generally improves outcome; however 45-55% of injuries still result in death or severe neurodevelopmental disability. We have developed a systems biology model of cerebral oxygen transport and metabolism to model the impact of hypothermia on the piglet brain (the neonatal preclinical animal model) tissue physiology. This computational model is an extension of the BrainSignals model of the adult brain. The model predicts that during hypothermia there is a 5.1% decrease in cerebral metabolism, 1.1% decrease in blood flow and 2.3% increase in cerebral tissue oxygenation saturation. The model can be used to simulate effects of hypothermia on the brain and to help interpret bedside recordings.


Asunto(s)
Circulación Cerebrovascular , Cerebro , Hipotermia , Modelos Biológicos , Animales , Animales Recién Nacidos , Circulación Cerebrovascular/fisiología , Cerebro/metabolismo , Simulación por Computador , Humanos , Hipotermia Inducida , Hipoxia-Isquemia Encefálica , Porcinos
2.
Adv Exp Med Biol ; 1232: 47-53, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31893393

RESUMEN

Cerebrovascular reactivity (CVR) is a compensatory mechanism where blood vessels dilate in response to a vasodilatory stimulus, and is a biomarker of vascular reserve and microvascular health. Impaired CVR indicates microvascular hemodynamic dysfunction, which is implicated in traumatic brain injury (TBI) and associated with long-term neurological deficiency. Recently we have shown that anodal transcranial direct current stimulation (tDCS) caused prolonged dilatation of cerebral arterioles that increased brain microvascular flow and tissue oxygenation in traumatized mouse brain and was associated with neurologic improvement. Here we evaluate the effects of tDCS on impaired CVR and microvascular cerebral blood flow (mCBF) regulation after TBI. TBI was induced in mice by controlled cortical impact (CCI). Cortical microvascular tone, mCBF, and tissue oxygen supply (by nicotinamide adenine dinucleotide, NADH) were measured by two-photon laser scanning microscopy before and after anodal tDCS (0.1 mA/15 min). CVR and mCBF regulation were evaluated by measuring changes in arteriolar diameters and NADH during hypercapnia test before and after tDCS. Transient hypercapnia was induced by 60-s increase of CO2 concentration in the inhalation mixture to 10%. As previously, anodal tDCS dilated arterioles which increased arteriolar blood flow volume that led to an increase in capillary flow velocity and the number of functioning capillaries, thereby improving tissue oxygenation in both traumatized and sham animals. In sham mice, transient hypercapnia caused transient dilatation of cerebral arterioles with constant NADH, reflecting intact CVR and mCBF regulation. In TBI animals, arteriolar dilatation response to hypercapnia was diminished while the NADH level increased (tissue oxygen supply decreased), reflecting impaired CVR and mCBF regulation. Anodal tDCS enhanced reactivity in parenchymal arterioles in both groups (especially in TBI mice) and restored CVR thereby prevented the reduction in tissue oxygen supply during hypercapnia. CVR has been shown to be related to nitric oxide elevation due to nitric oxide synthases activation, which can be sensitive to the electrical field induced by tDCS.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Circulación Cerebrovascular , Estimulación Transcraneal de Corriente Directa , Animales , Encéfalo/patología , Lesiones Traumáticas del Encéfalo/terapia , Circulación Cerebrovascular/fisiología , Hipercapnia , Ratones
3.
Adv Exp Med Biol ; 1232: 77-83, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31893397

RESUMEN

Instantaneous orthostatic hypotension (INOH) is one of the main types of orthostatic dysregulation in children and adolescents. In patients with INOH arterial pressure drops considerably after active standing and is slow to recover. We investigated changes in cerebral oxygenation in the bilateral prefrontal cortex during an active standing test in juvenile INOH patients to evaluate changes in cerebral oxygen metabolism. We enrolled 82 INOH patients (mean age 13.8 ± 2.2 years, 52 mild and 30 severe patients) at Nihon University Itabashi Hospital from October 2013 to April 2018. We measured cerebral oxygenated hemoglobin, deoxygenated hemoglobin, and total hemoglobin levels in the bilateral prefrontal cortex using near-infrared spectroscopy during an active standing test. In severe INOH patients, cerebral oxygenation of the right prefrontal cortex remained constant when blood pressure dropped; however, de-oxy-Hb significantly increased. These findings confirm that there is asymmetrical autoregulation between the right and left prefrontal cortex.


Asunto(s)
Circulación Cerebrovascular , Hipotensión Ortostática , Adolescente , Circulación Cerebrovascular/fisiología , Niño , Homeostasis , Humanos , Hipotensión Ortostática/fisiopatología , Oxihemoglobinas , Espectroscopía Infrarroja Corta
4.
Adv Exp Med Biol ; 1232: 85-90, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31893398

RESUMEN

Delayed orthostatic hypotension (OH) is a minor subset of orthostatic dysregulation (OD). Cerebral blood oxygenation in juvenile patients with delayed OH has not been studied. We investigated the bilateral changes in cerebral oxygenation in the prefrontal cortex during an active standing test in 23 juvenile patients with delayed OH using near-infrared spectroscopy (NIRS). We measured the oxy-Hb, deoxy-Hb, and total-Hb during the active standing test. Four observations were made during the test: t1 in a resting supine position, t2 when maintaining blood pressure, and the remaining two (t3, t4) during hypotension. The concentration of oxy-Hb significantly decreased prior to satisfying the diagnostic criteria of delayed OH after standing and did not change thereafter. The concentration of deoxy-Hb increased gradually during the measurement periods. In addition, total-Hb increased from t2 to t3. There was no significant difference in the change in each Hb parameter between the left and right cerebral hemispheres. Our results indicate that NIRS parameters are more sensitive than blood pressure for the interpretation of cerebral autoregulation in juvenile patients with delayed OH.


Asunto(s)
Sistema Cardiovascular , Circulación Cerebrovascular , Hipotensión Ortostática , Oxígeno , Posición de Pie , Adolescente , Presión Sanguínea , Circulación Cerebrovascular/fisiología , Humanos , Hipotensión Ortostática/sangre , Hipotensión Ortostática/diagnóstico , Oxígeno/sangre , Espectroscopía Infrarroja Corta
5.
Medicine (Baltimore) ; 99(4): e18998, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31977916

RESUMEN

The causes for falls in the elderly are varied, and visual spatial neglect could be 1 contributing factor. Further, the presence of a carotid artery plaque, especially on the right side, might influence the visual spatial attention of the elderly.Our aim was to identify the intrinsic association between carotid plaques and lateralization of spatial attention in the elderly. Further, we sought to understand and potentially prevent the consequences of unilateral spatial neglect such as injury from falls.Participants aged 64 to 93 years were divided into a group with carotid artery plaque(s) of the right side or both sides (BOTH, n = 38; and 9/ 38 were right side only) and a group without right-side carotid artery plaque(s) (LEFT, n = 53). Participants were asked to perform a line bisection task and undergo doppler ultrasonography examinations.Contrary to expectations, compared to LEFT, the mean index and net scores of the line bisection errors in BOTH were significantly less leftward, but the mean diameter of the right-side common carotid artery in BOTH was significantly larger.Our results indicate that the presence of carotid plaque(s) might be linked to increased risk of falls in the elderly. The attenuated spatial neglect in participants with right-side carotid artery plaque(s) might be due to compensatory carotid artery dilatation.


Asunto(s)
Accidentes por Caídas , Estenosis Carotídea/complicaciones , Trastornos de la Percepción/complicaciones , Anciano , Anciano de 80 o más Años , Arteria Carótida Común/patología , Arteria Carótida Interna/patología , Estudios de Casos y Controles , Circulación Cerebrovascular/fisiología , Estudios Transversales , Humanos , Persona de Mediana Edad , Factores de Riesgo
6.
World Neurosurg ; 133: e558-e566, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31562963

RESUMEN

OBJECTIVE: In pediatric patients with moyamoya disease, the pathophysiology of transient neurological deficits and the clinical features of perioperative cerebral blood flow (CBF) changes are unclear. The purpose of this study was to investigate the risk factors of postoperative transient neurological deficits and identify predictors of perioperative CBF changes. METHODS: This retrospective study included 42 surgical procedures in 28 pediatric patients who underwent surgical revascularization for moyamoya disease, including encephalo-myo-synangiosis (EMS) with or without superficial temporal artery-middle cerebral artery (MCA) anastomosis. Magnetic resonance images and single photon emission computed tomography results were obtained. Brain compression by EMS was also checked in fluid attenuated inversion recovery images. Using single photon emission computed tomography, CBF was measured at each anterior and posterior part of the MCA region. RESULTS: Postoperative transient neurological deficits were observed in 12 (28.6%) out of 42 surgical procedures. Brain compression by EMS was a significant risk for transient neurological deficits (P = 0.009). The postoperative CBF in the anterior region increased in 9 cases (21.4%) and decreased in 10 cases (23.8%); in the posterior region, it increased in 12 cases (28.6%) and decreased in 10 cases (23.8%). Preoperative CBF of the anterior region was significantly related to both perioperative CBF changes in the MCA regions (anterior part, P = 0.004; posterior part, P = 0.025). CONCLUSIONS: Brain compression by EMS is a risk factor for postoperative transient neurological deficits in pediatric patients with moyamoya disease, and preoperative CBF of the anterior MCA region could predict perioperative CBF change in the MCA regions.


Asunto(s)
Revascularización Cerebral/efectos adversos , Revascularización Cerebral/métodos , Enfermedad de Moyamoya/cirugía , Complicaciones Posoperatorias/etiología , Circulación Cerebrovascular/fisiología , Niño , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo
7.
World Neurosurg ; 133: e522-e528, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31550537

RESUMEN

OBJECTIVE: We aimed to compare flat detector computed tomography cerebral blood volume (FD-CBV) imaging to single-photon emission computed tomography (SPECT) as an adjunctive technique during balloon test occlusion (BTO) in patients with intracranial aneurysms or tumors. METHODS: Twelve patients who underwent SPECT (99mTc-ethyl cysteinate dimer) and FD-CBV imaging during BTO were enrolled. Color-coded cerebral blood flow (CBF) images and color-coded FD-CBV images were generated and visually inspected whether there were asymmetries between the ipsilateral and contralateral cerebral hemispheres. Region of interest measurements were performed on the color-coded images at the same locations for both modalities. The mean interhemispheric region of interest ratios were calculated, and the ratio between these were estimated using linear regression models. RESULTS: Ten patients had no symptoms during BTO. Two patients developed subtle but inconclusive neurologic changes approximately 10 minutes after balloon inflation; their images showed asymmetric color-coded images with decreased CBF and FD-CBV in the ipsilateral hemisphere. The mean interhemispheric ratio of CBF was significantly smaller in patients with subtle changes than in those without (0.84 vs. 0.98; P < 0.001). Similarly, the mean interhemispheric ratio of FD-CBV was significantly smaller in patients with subtle changes than in those without (0.88 vs. 1.06; P = 0.01). No patient showed increased CBF or FD-CBV in the ipsilateral hemisphere. CONCLUSIONS: The patients with decreased CBF on SPECT also showed decreased FD-CBV in the ipsilateral hemisphere. FD-CBV imaging may be useful as an adjunctive technique for BTO before potential therapeutic carotid artery occlusion.


Asunto(s)
Arteriopatías Oclusivas/diagnóstico por imagen , Oclusión con Balón/métodos , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Arteriopatías Oclusivas/cirugía , Enfermedades de las Arterias Carótidas/cirugía , Circulación Cerebrovascular/fisiología , Femenino , Humanos , Masculino , Neuroimagen/métodos
9.
Life Sci ; 237: 116929, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31610210

RESUMEN

LncRNA small nucleolar RNA host gene 3 (Snhg3) has been involved in cell proliferation and migration in malignant cells. However, its role in regulating functions of non-malignant cells has been hardly reported. Here, we found Snhg3 expression was sharply induced in primary brain microvascular endothelial cells (BMVECs) treated with oxygen-and-glucose-deprivation (OGD) plus hemin, an in vitro model of intracerebral hemorrhage (ICH). Downregulation of Snhg3 by siRNA transfection improved cell proliferation and migration abilities and reduced cell apoptosis and monolayer permeability in BMVECs under treatment with OGD plus hemin. Snhg3 overexpression suppressed cell proliferation and migration and increased cell apoptosis and monolayer permeability under normal condition. In ICH rats, downregulation of Snhg3 by siRNA injection improved behavioral and histological manifestations, including number of right turns, limb placement score, integrity of blood-brain barrier (BBB), brain water content and cell apoptosis in vivo. In the mechanism exploration, we found that, TWEAK and Snhg3 displayed a positive correlation with each other. Snhg3 overexpression increased expression of TWEAK protein and its receptor Fn14, that were also induced by OGD plus hemin, activating the downstream neuroinflammatory pathway STAT3 and enhancing the secretion of MMP-2/9. Finally, the TWEAK-siRNA, the Fn14 inhibitor ATA and the STAT3 blocker AG490 were respectively used to treat BMVECs under treatment with OGD plus hemin. Our results showed either TWEAK downregulation, Fn14 inhibition, or STAT3 blockade, could rescue Snhg3-induced impairment of BMVEC functions. In conclusion, the lncRNA Snhg3 contributes to dysfunction of cerebral microvascular cells in ICH rats by activating the TWEAK/Fn14/STAT3 pathway.


Asunto(s)
Encéfalo/patología , Hemorragia Cerebral/patología , Citocina TWEAK/metabolismo , Endotelio Vascular/patología , ARN Largo no Codificante/genética , Factor de Transcripción STAT3/metabolismo , Receptor de TWEAK/metabolismo , Animales , Conducta Animal , Encéfalo/metabolismo , Células Cultivadas , Hemorragia Cerebral/genética , Hemorragia Cerebral/metabolismo , Circulación Cerebrovascular/fisiología , Citocina TWEAK/genética , Endotelio Vascular/metabolismo , Regulación de la Expresión Génica , Masculino , Microvasos/metabolismo , Microvasos/patología , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT3/genética , Receptor de TWEAK/genética , Cicatrización de Heridas
11.
Cochrane Database Syst Rev ; 9: CD013201, 2019 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-31549743

RESUMEN

BACKGROUND: Germinal matrix-intraventricular haemorrhage (GMH-IVH) remains a substantial issue in neonatal intensive care units worldwide. Current therapies to prevent or treat GMH-IVH are limited. Stem cell-based therapies offer a potential therapeutic approach to repair, restore, and/or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal studies. OBJECTIVES: To determine the benefits and harms of stem cell-based interventions for prevention or treatment of germinal matrix-intraventricular haemorrhage (GM-IVH) in preterm infants. SEARCH METHODS: We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1), in the Cochrane Library; MEDLINE via PubMed (1966 to 7 January 2019); Embase (1980 to 7 January 2019); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 7 January 2019). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. SELECTION CRITERIA: We attempted to identify randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing (1) stem cell-based interventions versus control; (2) mesenchymal stromal cells (MSCs) of type or source versus MSCs of other type or source; (3) stem cell-based interventions other than MSCs of type or source versus stem cell-based interventions other than MSCs of other type or source; or (4) MSCs versus stem cell-based interventions other than MSCs. For prevention studies, we included extremely preterm infants (less than 28 weeks' gestation), 24 hours of age or less, without ultrasound diagnosis of GM-IVH; for treatment studies, we included preterm infants (less than 37 weeks' gestation), of any postnatal age, with ultrasound diagnosis of GM-IVH. DATA COLLECTION AND ANALYSIS: For each of the included trials, two review authors independently planned to extract data (e.g. number of participants, birth weight, gestational age, type and source of MSCs, other stem cell-based interventions) and assess the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). Primary outcomes considered in this review are all-cause neonatal mortality, major neurodevelopmental disability, GM-IVH, and extension of pre-existing non-severe GM-IVH. We planned to use the GRADE approach to assess the quality of evidence. MAIN RESULTS: Our search strategy yielded 769 references. We did not find any completed studies for inclusion. One randomised controlled trial is currently registered and ongoing. Five phase 1 trials are described in the excluded studies. AUTHORS' CONCLUSIONS: Currently no evidence is available to show the benefits or harms of stem cell-based interventions for treatment or prevention of GM-IVH in preterm infants.


Asunto(s)
Hemorragia Cerebral/prevención & control , Circulación Cerebrovascular/fisiología , Mortalidad Infantil , Recien Nacido Extremadamente Prematuro , Enfermedades del Prematuro/prevención & control , Células Madre , Humanos , Lactante , Recién Nacido de Bajo Peso , Recién Nacido , Enfermedades del Prematuro/etiología , Ensayos Clínicos Controlados Aleatorios como Asunto
12.
J Comput Assist Tomogr ; 43(5): 697-707, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31490889

RESUMEN

OBJECTIVE: To explore the application value of postlabeling delay (PLD) in 3D pseudocontinuous arterial spin-labeled (3D-pcASL) perfusion imaging in normal children and to find the optimal PLD values for children at each age group. METHODS: Five groups of children, with 50 patients in each group, who underwent routine magnetic resonance imaging scans with normal results were included. The patients were stratified according to the following ages: younger than 1 month, more than 1 month to 6 months, more than 6 months to 12 months, more than 1 year to 3 years, more than 3 years to 6 years, and more than 6 years to 18 years. All patients received 3D-pcASL perfusion magnetic resonance scanning. The PLD values were set to 1025, 1525, or 2025 milliseconds. In subjective evaluations, the signal-to-noise ratio (SNR) and cerebral blood flow (CBF) of 3D-pcASL perfusion images under different PLD values were compared and analyzed. RESULTS: For patients in the <1-month group and >1-month to 6-month group, the images were mainly grade A when the PLD value was 1025 milliseconds, which equaled 43 and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1525 and 2025 milliseconds. For patients in the >6-month to 12-month group, >1-year to 3-year group, >3-year to 6-year group, and >6-year to 18-year group, the images were mainly grade A when the PLD value was 1525 milliseconds, which equaled 43, 45, 43, and 46 cases, respectively. The brain CBF values and SNR values were higher than those of the images with PLD values of 1025 and 2025 milliseconds. CONCLUSIONS: The optimal PLD values for 3D-pcASL perfusion imaging are different in children of different ages. The optimal PLD value for infants who are 6 months younger is 1025 milliseconds. The optimal PLD value for children older than 6 months to 18 years is 1525 milliseconds.


Asunto(s)
Encéfalo/irrigación sanguínea , Arterias Cerebrales/diagnóstico por imagen , Circulación Cerebrovascular/fisiología , Imagen por Resonancia Magnética/métodos , Imagen de Perfusión/métodos , Adolescente , Niño , Preescolar , Femenino , Humanos , Imagen Tridimensional , Lactante , Recién Nacido , Masculino , Valores de Referencia , Marcadores de Spin
13.
J Neurol Surg A Cent Eur Neurosurg ; 80(6): 441-453, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31466106

RESUMEN

OBJECTIVE: To investigate the difference in treatment outcomes according to the method used to select the recipient artery in superficial temporal artery-middle cerebral artery (STA-MCA) anastomoses. METHODS: We retrospectively analyzed the cases of 35 patients who underwent an STA-MCA anastomosis for internal carotid artery/MCA occlusion or stenosis. Patients were divided into two groups based on whether the recipient artery was precisely targeted by single-photon emission computed tomography (SPECT group) or less precisely targeted by visual assessment (Visual group). Then the bypass results in both groups were evaluated postoperatively based on changes in the regional cerebral blood flow (rCBF) and clinical outcomes. RESULTS: The delineated recipient artery in magnetic resonance angiography (MRA) matched the intraoperatively selected artery in 87.6% of the SPECT group cases and 83.3% of the Visual group cases. The SPECT group's digital subtraction angiography (DSA) findings coincided with the intraoperative selection in 76.9% of cases, and the MRA findings corresponded with the DSA findings in 92.3%. The postoperative areas with increased rCBF matched the perfused areas of intraoperatively selected arteries in 80.0% of the SPECT group cases and 77.8% of the Visual group cases. Postoperatively increased rCBF areas matching totally or partially with preoperative low-perfusion areas were observed in all cases. CONCLUSIONS: The present results revealed no significant differences in the change in rCBF in the low-perfusion area between the patients whose recipient arteries were selected by SPECT or visual assessment.


Asunto(s)
Anastomosis Quirúrgica/métodos , Estenosis Carotídea/cirugía , Arteria Cerebral Media/cirugía , Arterias Temporales/cirugía , Anciano , Angiografía de Substracción Digital , Estenosis Carotídea/diagnóstico por imagen , Revascularización Cerebral/métodos , Circulación Cerebrovascular/fisiología , Femenino , Humanos , Angiografía por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/diagnóstico por imagen , Estudios Retrospectivos , Arterias Temporales/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Resultado del Tratamiento
14.
PLoS Comput Biol ; 15(8): e1007231, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31469820

RESUMEN

Capillaries are the prime location for oxygen and nutrient exchange in all tissues. Despite their fundamental role, our knowledge of perfusion and flow regulation in cortical capillary beds is still limited. Here, we use in vivo measurements and blood flow simulations in anatomically accurate microvascular network to investigate the impact of red blood cells (RBCs) on microvascular flow. Based on these in vivo and in silico experiments, we show that the impact of RBCs leads to a bias toward equating the values of the outflow velocities at divergent capillary bifurcations, for which we coin the term "well-balanced bifurcations". Our simulation results further reveal that hematocrit heterogeneity is directly caused by the RBC dynamics, i.e. by their unequal partitioning at bifurcations and their effect on vessel resistance. These results provide the first in vivo evidence of the impact of RBC dynamics on the flow field in the cortical microvasculature. By structural and functional analyses of our blood flow simulations we show that capillary diameter changes locally alter flow and RBC distribution. A dilation of 10% along a vessel length of 100 µm increases the flow on average by 21% in the dilated vessel downstream a well-balanced bifurcation. The number of RBCs rises on average by 27%. Importantly, RBC up-regulation proves to be more effective the more balanced the outflow velocities at the upstream bifurcation are. Taken together, we conclude that diameter changes at capillary level bear potential to locally change the flow field and the RBC distribution. Moreover, our results suggest that the balancing of outflow velocities contributes to the robustness of perfusion. Based on our in silico results, we anticipate that the bi-phasic nature of blood and small-scale regulations are essential for a well-adjusted oxygen and energy substrate supply.


Asunto(s)
Encéfalo/irrigación sanguínea , Eritrocitos/fisiología , Microvasos/fisiología , Animales , Velocidad del Flujo Sanguíneo/fisiología , Capilares/anatomía & histología , Capilares/fisiología , Circulación Cerebrovascular/fisiología , Biología Computacional , Simulación por Computador , Femenino , Hematócrito , Ratones , Ratones Endogámicos C57BL , Microvasos/anatomía & histología , Modelos Cardiovasculares , Modelos Neurológicos , Vasodilatación/fisiología
15.
Int J Comput Assist Radiol Surg ; 14(10): 1805-1813, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31363984

RESUMEN

PURPOSE: Image-based hemodynamic simulations have great potential for precise blood flow predictions in intracranial aneurysms. Due to model assumptions and simplifications with respect to boundary conditions, clinical acceptance remains limited. METHODS: Within this study, we analyzed the influence of outflow-splitting approaches on multiple aneurysm studies and present a new outflow-splitting approach that takes the precise morphological vessel cross sections into account. We provide a detailed comparison of five outflow strategies considering eight intracranial aneurysms: zero-pressure configuration (1), a flow splitting inspired by Murray's law with a square (2) and a cubic (3) vessel diameter, a flow splitting incorporating vessel bifurcations based on circular vessel cross sections (4) and our novel flow splitting including vessel bifurcations and anatomical vessel cross sections (5). Other boundary conditions remain constant. For each simulation and each aneurysm, we conducted an evaluation based on common hemodynamic parameters, e.g., normalized wall shear stress and inflow concentration index. RESULTS: The comparison of five outflow strategies for image-based simulations shows a large variability regarding the parameters of interest. Qualitatively, our strategy based on anatomical cross sections yields a more uniform flow rate distribution with increased aneurysm inflow rates. The commonly used zero-pressure approach shows the largest variations, especially for more distal aneurysms. A rank ordering of multiple aneurysms in one patient might still be possible, since the ordering appeared to be independent of the outflow strategy. CONCLUSIONS: The results reveal that outlet boundary conditions have a crucial impact on image-based blood flow simulations, especially for multiple aneurysm studies. We could confirm the advantages of the more complex outflow-splitting model (4) including an incremental improvement (5) compared to strategies (1), (2) and (3) for this application scenario. Furthermore, we discourage from using zero-pressure configurations that lack a physiological basis.


Asunto(s)
Circulación Cerebrovascular/fisiología , Simulación por Computador , Aneurisma Intracraneal/fisiopatología , Modelos Cardiovasculares , Velocidad del Flujo Sanguíneo/fisiología , Hemodinámica/fisiología , Humanos , Procesamiento de Imagen Asistida por Computador/métodos
16.
World Neurosurg ; 130: e1111-e1115, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31323417

RESUMEN

BACKGROUND: The development of venous outflow stenosis in cerebral arteriovenous malformation (AVM) is poorly understood. The location of stenosis within the AVM draining vein in relation to the adjacent venous sinus and the hypothesis that the ratio of draining vein to adjacent sinus diameter might predict the development of venous stenosis were explored. METHODS: Patients with supratentorial AVMs (1997-2018) were reviewed (N = 290). AVM draining vein and adjacent venous sinus diameters, degree of draining vein stenosis, and distance from the maximal stenotic point to the junction of the adjacent draining sinus were recorded. Correlation between percentage of AVM draining vein stenosis and the ratio of AVM draining vein to venous sinus diameters was analyzed. RESULTS: A total of 360 draining veins in 243 AVMs with complete angiographic data were measured. Venous stenosis (in 131 draining veins) was observed within 20 mm of the junction to the adjacent draining sinus in 85% of our sample. The ratio of draining vein to adjacent sinus diameter correlated positively with the percentage of venous stenosis (P < 0.01, r = 0.21). The ratio between 0.51-1.0 and >1.0 showed significant tighter stenosis compared with the ratio ≤0.5 (25.9% and 28.9% vs. 10.0%, respectively; P < 0.01). CONCLUSIONS: AVM venous outflow stenosis is observed close to the adjacent venous sinus junction. The degree of venous stenosis is greater when the ratio of AVM draining vein/adjacent venous sinus diameter is >0.5. This may be related to more turbulent flow at the junction of the draining vein and venous sinus, especially in larger draining veins, which causes venous stenosis to develop over time.


Asunto(s)
Venas Cerebrales/diagnóstico por imagen , Senos Craneales/diagnóstico por imagen , Malformaciones Arteriovenosas Intracraneales/complicaciones , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Circulación Cerebrovascular/fisiología , Niño , Preescolar , Estudios de Cohortes , Constricción Patológica/diagnóstico por imagen , Constricción Patológica/epidemiología , Constricción Patológica/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
17.
Appl Physiol Nutr Metab ; 44(8): 894-901, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31313969

RESUMEN

There is only scarce information regarding the physiological and health impact of lifelong wearing of the neck brass coils in Karen Kayan women. The purpose of this study was to determine the influence of wearing brass neck coils on cardiorespiratory and cerebrovascular functions in long-neck Karen women. A total of 28 Karen women (aged 23-66 years) were studied. Fourteen Karen women who had been wearing neck brass coils were compared with 14 Karen women with no neck coils. We also studied 14 age-matched city-living controls. Radiographic examination of 2 older Karen women wearing neck coils showed low levels of the clavicles. There were no group differences in resting heart rate and brachial-ankle pulse wave velocity. Both systolic and diastolic blood pressure was greater and functional capacity was lower in both Karen women than city-living controls (all p < 0.05). Karen women wearing neck coils demonstrated lower flow-mediated dilation, lung functions, including forced vital capacity and forced expiratory volume during the first second, and cerebral blood flow velocity than Karen women without neck coils (all p < 0.05). Karen women wearing neck coils demonstrate reduced endothelial and pulmonary functions as well as cerebral perfusion compared with age-matched Karen women without neck coils living in the same villages. Brass neck coils worn by Karen women may elevate risks of developing cardiopulmonary and cerebrovascular diseases. Novelty Cerebral blood flow velocity and macrovascular and microvascular functions were lower in Karen wearing neck coils. There appears to be substantial burden of brass neck coils exerted on physiological systems in Karen women.


Asunto(s)
Presión Sanguínea , Arteria Braquial/fisiología , Circulación Cerebrovascular/fisiología , Volumen Espiratorio Forzado , Capacidad Vital , Adulto , Anciano , Femenino , Humanos , Pulmón , Persona de Mediana Edad , Tailandia/etnología , Adulto Joven
18.
World J Pediatr Congenit Heart Surg ; 10(4): 464-468, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31307306

RESUMEN

OBJECTIVES: To review the outcomes of direct innominate artery cannulation for continuous cerebral perfusion used for repair of interrupted aortic arch (IAA) in a consecutive cohort of neonates regardless of weight. METHODS: Between September 1999 and April 2016, forty-four children with IAA (18 type A and 26 type B) underwent repair using continuous, hypothermic (18°C) low-flow cerebral perfusion via direct innominate artery cannulation. Associated cardiac lesions were truncus arteriosus (TA; 5), ventricular septal defect (VSD; 30), transposition of the great arteries (TGA; 1), unbalanced atrioventricular septal defect (1), double-inlet left ventricle (1), double-outlet right ventricle (3), and aortopulmonary window (APW; 5). Truncus arteriosus, single VSD, TGA, and APW were corrected while the other patients were palliated. RESULTS: Age at the time of surgery was 7 days (4-120 days) and weight 3.1 kg (2.1-5.8 kg). Selective cerebral perfusion was maintained in all patients. During the selective cerebral perfusion, perfusion flow rate was maintained at 30 mL/kg/min. Aortic cross-clamp time, low-flow, and total cardiopulmonary bypass time were 63 (40-116), 28 (17-41), and 108 (80-217) minutes, respectively. There were no deaths nor clinical evidence of neurological injury. Postoperative ventilation time, length of intensive care unit, and hospital stay were 3 (2-14), 5 (3-21), and 13 (6-27) days, respectively. Follow-up, complete at 84 months (24-221), revealed no late clinically evident neurologic sequelae nor innominate artery complications. CONCLUSIONS: Direct innominate arterial cannulation with continuous selective cerebral perfusion can be safely applied for repair of IAA even in low birth weight neonates. It is technically simple and associated with excellent clinical outcomes.


Asunto(s)
Aorta Torácica/anomalías , Cateterismo/métodos , Circulación Cerebrovascular/fisiología , Recién Nacido de Bajo Peso , Perfusión/métodos , Malformaciones Vasculares/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Angiografía , Aorta Torácica/cirugía , Femenino , Humanos , Recién Nacido , Masculino , Resultado del Tratamiento , Malformaciones Vasculares/fisiopatología
19.
Anesthesiology ; 131(3): 512-520, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31261258

RESUMEN

BACKGROUND: Little is known about how implementation of pneumoperitoneum and head-up tilt position contributes to general anesthesia-induced decrease in cerebral blood flow in humans. We investigated this question in patients undergoing laparoscopic cholecystectomy, hypothesizing that cardiorespiratory changes during this procedure would reduce cerebral perfusion. METHODS: In a nonrandomized, observational study of 16 patients (American Society of Anesthesiologists physical status I or II) undergoing laparoscopic cholecystectomy, internal carotid artery blood velocity was measured by Doppler ultrasound at four time points: awake, after anesthesia induction, after induction of pneumoperitoneum, and after head-up tilt. Vessel diameter was obtained each time, and internal carotid artery blood flow, the main outcome variable, was calculated. The authors recorded pulse contour estimated mean arterial blood pressure (MAP), heart rate (HR), stroke volume (SV) index, cardiac index, end-tidal carbon dioxide (ETCO2), bispectral index, and ventilator settings. Results are medians (95% CI). RESULTS: Internal carotid artery blood flow decreased upon anesthesia induction from 350 ml/min (273 to 410) to 213 ml/min (175 to 249; -37%, P < 0.001), and tended to decrease further with pneumoperitoneum (178 ml/min [127 to 208], -15%, P = 0.026). Tilt induced no further change (171 ml/min [134 to 205]). ETCO2 and bispectral index were unchanged after induction. MAP decreased with anesthesia, from 102 (91 to 108) to 72 (65 to 76) mmHg, and then remained unchanged (Pneumoperitoneum: 70 [63 to 75]; Tilt: 74 [66 to 78]). Cardiac index decreased with anesthesia and with pneumoperitoneum (overall from 3.2 [2.7 to 3.5] to 2.3 [1.9 to 2.5] l · min · m); tilt induced no further change (2.1 [1.8 to 2.3]). Multiple regression analysis attributed the fall in internal carotid artery blood flow to reduced cardiac index (both HR and SV index contributing) and MAP (P < 0.001). Vessel diameter also declined (P < 0.01). CONCLUSIONS: During laparoscopic cholecystectomy, internal carotid artery blood flow declined with anesthesia and with pneumoperitoneum, in close association with reductions in cardiac index and MAP. Head-up tilt caused no further reduction. Cardiac output independently affects human cerebral blood flow.


Asunto(s)
Anestesia General , Arteria Carótida Interna/fisiología , Circulación Cerebrovascular/fisiología , Colecistectomía Laparoscópica , Neumoperitoneo/terapia , Postura/fisiología , Adulto , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Arteria Carótida Interna/efectos de los fármacos , Femenino , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Ultrasonografía Doppler , Adulto Joven
20.
Georgian Med News ; (290): 38-44, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31322512

RESUMEN

The association of cerebral arteriovenous malformations (bAVM) and associated paranidal aneurysms, that is closely related to the AVM nidus, carry a high risk of rapture and re-rapture after initial hemorrhage. This association is consider as therapeutic challenge and supportive data about their natural history and best treatment modalities are still lacking. In this article we report our experience of their treatment. We reviewed 443 cases of patients with AVMs between 2004 and 2018, who were treated at our institution and found 73 (16,5%) cases of AVM association with paranidal aneurysms (22 (30,2%) arterial - prenidal, 20 (27,4%) intranidal, and 19 (26,0%) venous - postnidal). Twelve (16,4 %) patients had multiple aneurysm. All patients received endovascular treatment with n-butyl cyanoacrylate (NBCA), ONYX or Embolin embolization. We evaluated clinical and radiological data, treatment and outcomes at discharge. Among 73 patients (32 (43,8 %) women and 41 (56,2 %) men, mean age - 34 years, 8 - 65 years) with AVM and paranidal aneurysms who were enrolled in our study, hemorrhage was the most frequent presenting symptom (47 patients (64.4%). The timing of procedure varied between 3 - 23 days. Total occlusion of AVM was achieved in 23 (31,5%) cases, in all other cases partial or target occlusion with obligatory aneurysm embolization was done. Seven (9,6%) patients had complication (5 ischemic and 2 hemorrhagic) after procedure. Clinical improvement was seen in all groups at discharge. Mean change of mRS score between admission and discharge was 0,2-0,5 point. Excellent or good outcome (mRS - 0,1,2) was observed in 58 (79,5%) patients at discharge. Unfavorable outcome (mRS - 3-5) had 13 (17,8%) patients, mRS - 6 - 2 (2,7%) patients. Patients sustaining AVM and multiple paranidal aneurysms had higher risk of hemorrhage comparing with single one (OR-17,5 (95% CI -1,0-309,8 (p=0,010). Relationship between AVM with paranidal aneurysms and hemorrhagic presentation is obvious, however definite source of hemorrhage is difficult to evaluate. To our belief arterial prenidal and intranidal aneurysms especially multiple are the most dangerous and should be in therapeutic focus after it's finding. Endovascular embolization has the potential to be effective and safe in treatment of AVM with paranidal aneurysms.


Asunto(s)
Arterias/diagnóstico por imagen , Hemorragia Cerebral/etiología , Embolización Terapéutica , Aneurisma Intracraneal/complicaciones , Aneurisma Intracraneal/terapia , Malformaciones Arteriovenosas Intracraneales/complicaciones , Malformaciones Arteriovenosas Intracraneales/terapia , Adolescente , Adulto , Anciano , Angiografía Cerebral , Circulación Cerebrovascular/fisiología , Niño , Femenino , Humanos , Aneurisma Intracraneal/patología , Malformaciones Arteriovenosas Intracraneales/patología , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto Joven
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