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1.
BMC Pregnancy Childbirth ; 22(1): 15, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34986835

RESUMO

BACKGROUND: Unequal placental territory in monochorionic diamniotic twins is a primary cause of selective fetal growth restriction (sFGR), and vascular anastomoses play important role in determining sFGR prognosis. This study investigated differences in placental characteristics and pregnancy outcomes in cases of sFGR with and without thick arterio-arterial anastomosis (AAA). METHODS: A total of 253 patients diagnosed with sFGR between April 2013 and April 2020 were retrospectively analyzed. An AAA greater than 2 mm in diameter was defined as a thick AAA. We compared placental characteristics and pregnancy outcomes between cases of sFGR with and without thick AAA. RESULTS: Prevalence of AAA, thick arterio-venous anastomosis (AVA), veno-venous anastomosis (VVA), and thick VVA were significantly higher in the thick AAA group relative to the non-thick AAA group (100.0 vs. 78.5%, P < 0.001; 44.3 vs. 15.4%, P < 0.001; 27.1 vs. 10.8%, P = 0.017, and 24.3 vs. 6.2%, P = 0.004, respectively). The total numbers of AVA and total anastomoses were significantly higher in thick AAA group relative to the non-thick AAA group (5 [1, 14] vs. 3 [1, 15, P = 0.016; and 6 [1, 15] vs. 5 [1, 16], P = 0.022, respectively). The total diameter of AAA, AVA, VVA, and all anastomoses in the thick AAA group was larger than in the non-thick AAA group (3.4 [2.0,7.1] vs. 1.4 [0.0, 3.3], P < 0.001; 6.3 [0.3, 12.0] vs. 2.5 [0.3, 17.8], P < 0.001; 4.2±1.8 vs. 1.9±1.2, P =0.004; and 10.7 [3.2,22.4] vs. 4.4 [0.5, 19.3], P < 0.001, respectively). Growth-restricted fetuses in the thick AAA group exhibited significantly increased birthweight relative to those in thenon-thick AAA group (1570 (530, 2460)g vs. 1230 (610, 2480)g, p = 0.002). CONCLUSIONS: In the placentas associated with sFGR, thick AAA can co-occur with thick AVA and VVA, and placental angiogenesis may differ significantly based upon whether or not thick AAA is present. The birth weights of growth-restricted fetuses in cases of sFGR with thick AAA are larger than in cases without thick AAA.


Assuntos
Retardo do Crescimento Fetal/patologia , Placenta/irrigação sanguínea , Resultado da Gravidez , Gravidez de Gêmeos , Gêmeos Monozigóticos , Adulto , Anastomose Arteriovenosa/patologia , Peso ao Nascer , Feminino , Humanos , Gravidez , Estudos Retrospectivos , Artérias Umbilicais/irrigação sanguínea
2.
Sci Rep ; 11(1): 12153, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108499

RESUMO

Arteriovenous grafts are routinely placed to facilitate hemodialysis in patients with end stage renal disease. These grafts are conduits between higher pressure arteries and lower pressure veins. The connection on the vein end of the graft, known as the graft-to-vein anastomosis, fails frequently and chronically due to high rates of stenosis and thrombosis. These failures are widely believed to be associated with pathologically high and low flow shear strain rates at the graft-to-vein anastomosis. We hypothesized that consistent with pipe flow dynamics and prior work exploring vein-to-artery anastomosis angles in arteriovenous fistulas, altering the graft-to-vein anastomosis angle can reduce the incidence of pathological shear rate fields. We tested this via computational fluid dynamic simulations of idealized arteriovenous grafts, using the Bird-Carreau constitutive law for blood. We observed that low graft-to-vein anastomosis angles ([Formula: see text]) led to increased incidence of pathologically low shear rates, and that high graft-to-vein anastomosis angles ([Formula: see text]) led to increased incidence of pathologically high shear rates. Optimizations predicted that an intermediate  ([Formula: see text]) graft-to-anastomosis angle was optimal. Our study demonstrates that graft-to-vein anastomosis angles can significantly impact pathological flow fields, and can be optimized to substantially improve arteriovenous graft patency rates.


Assuntos
Anastomose Arteriovenosa/cirurgia , Fístula Arteriovenosa/prevenção & controle , Derivação Arteriovenosa Cirúrgica/normas , Simulação por Computador , Falência Renal Crônica/terapia , Modelos Cardiovasculares , Diálise Renal/efeitos adversos , Fístula Arteriovenosa/etiologia , Velocidade do Fluxo Sanguíneo , Hemodinâmica , Humanos , Estresse Mecânico
3.
Bull Tokyo Dent Coll ; 62(2): 63-70, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33994422

RESUMO

While a digital arteriovenous anastomosis (Hoyer-Grosser's organ, Masson's glomus) is a well-known structure, photographic evidence of communication between arterial and venous lumens might not be demonstrated in routine histological or immunohistochemical analysis. Abundant clusters of so-called glomera were found in semi-serial sections of the distal aspect of 14 fingers obtained from 7 donated elderly cadavers. Two to six round or oval clusters were observed in each longitudinal section (over 0.3-0.6 mm in maximum diameter) in subcutaneous tissue 0.5-1.5 mm below the basal layer of the skin, whereas none were often observed in transverse sections. Lumen-to-lumen communication between arteriole and venule at 8 sites in 2 cadavers was identified in these clusters of glomera. The opening in the arteriole was large (50 µm in diameter) at 3 sites in specimens from an 80-year-old man, whereas it was small (10-30 µm) at 5 sites in those from a 91-year-old man. The arterial aspect was tightly surrounded by abundant nerve fibers expressing tyrosine hydroxylase immunoreactivity, whereas the venous part was not. No or little expression of S100 protein immunoreactivity suggested that these nerve fibers were unmyelinated. The morphology at the lumen-to-lumen communication was simple - possibly an end-to-end anastomosis - rather than a sinuous curve of arteriole opening on to a short funnel-shaped venule as seen in the standard textbooks.


Assuntos
Anastomose Arteriovenosa , Dedos , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino
4.
Neurosurgery ; 89(1): 60-69, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33770182

RESUMO

BACKGROUND: High-definition vascular imaging is desirable for treatment planning in Gamma Knife radiosurgery (GKRS; Elekta AB) for brain arteriovenous malformations (BAVMs). Currently, rotational angiography (RA) provides the clearest 3-dimensional visualization of niduses with high spatial resolution; however, its efficacy for GKRS has not been clarified. At our institution, RA has been integrated into GKRS (RA-GKRS) for better treatment planning and outcomes since 2015. OBJECTIVE: To evaluate RA-GKRS outcomes of BAVMs and compare them with conventional GKRS (c-GKRS) outcomes. METHODS: We retrospectively analyzed the radiosurgical outcomes of 50 BAVMs treated with RA-GKRS compared with the 306 BAVMs treated with c-GKRS. Considering possible differences in the baseline characteristics, we also created propensity score-matched cohorts and compared the radiosurgical outcomes between them to ensure comparability. RESULTS: The obliteration time was shorter in the RA-GKRS group (cumulative rate, 88% vs 65% at 4 yr [P = .001]). Multivariate Cox proportional hazards analysis demonstrated that the RA-GKRS group (hazard ratio 2.38, 95% CI 1.58-3.60; P = .001) had a better obliteration rate. The cumulative 4-yr post-GKRS hemorrhage rates were 4.0% and 2.6% in the RA-GKRS and c-GKRS groups, respectively (P = .558). There was a trend toward early post-GKRS signal change in the RA-GKRS group compared with the c-GKRS group (cumulative rate, 38% vs 29% at 2 yr; P = .118). Those results were also confirmed in the matched cohort analyses. CONCLUSION: The integration of RA into GKRS is promising and may provide earlier nidus obliteration.


Assuntos
Encéfalo/cirurgia , Transtornos Cerebrovasculares/cirurgia , Malformações Arteriovenosas Intracranianas , Radiocirurgia , Angiografia , Anastomose Arteriovenosa , Humanos , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Malformações Arteriovenosas Intracranianas/cirurgia , Estudos Retrospectivos , Resultado do Tratamento
5.
São Paulo; s.n; 2021.
Tese em Português | LILACS, Coleciona SUS, Sec. Munic. Saúde SP, HSPM-Producao, Sec. Munic. Saúde SP | ID: biblio-1348353

RESUMO

RESUMO A anastomose vascular é uma das competências técnicas e motoras esperadas de um cirurgião vascular. O tempo, o refinamento e a qualidade da anastomose influem na patência vascular, nos resultados e nas possíveis complicações cirúrgicas. Por se tratar de uma habilidade motora, praticar a anastomose é necessário. O treinamento baseado em repetição, optando por modelos sintéticos a animais e visando a segurança do paciente é fundamental. Entretanto, no Brasil dispomos de poucos simuladores, em sua maioria, importados e de alto custo. A análise de modelos disponíveis no mercado nacional e no exterior levou a confecção de modelo de baixo custo para treinamento de anastomoses vasculares a partir de uma mistura de gelatina, glicerina e malha têxtil. Os testes realizados no modelo desenvolvido demonstraram que ele é eficiente e auxilia no treinamento de anastomoses vasculares. Palavras-chaves: Treinamento por Simulação. Anastomose Arteriovenosa. Técnica de Sutura.


Assuntos
Humanos , Masculino , Feminino , Anastomose Arteriovenosa , Suturas , Treinamento por Simulação
6.
J Physiol Anthropol ; 39(1): 37, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228778

RESUMO

BACKGROUND: Cold-induced vasodilation (CIVD) is known to be influenced by the ambient temperature. Frequency analysis of blood flow provides information on physiological regulation of the cardiovascular system, such as myogenic, neurogenic, endothelial nitric oxide (NO) dependent, and NO-independent activities. In this study, we hypothesized that the major origin of CIVD occurs prior to the CIVD event and investigated finger skin blood flow during the initial stage of CIVD at different ambient temperatures using frequency analysis. METHODS: Eighteen healthy volunteers immersed their fingers in 5 °C water at air temperatures of 20 °C and 25 °C. Finger skin blood flow was measured using laser Doppler flowmetry and analyzed using Morlet mother wavelet. We defined the time when the rate of blood flow increased dramatically as the onset of CIVD, and defined three phases as the periods from the onset of cooling to minimum blood flow (vasoconstriction), from minimum blood flow to the onset of CIVD (prior to CIVD), and from the onset of CIVD to maximum blood flow (CIVD). RESULTS: The increment ratio of blood flow at CIVD was significantly higher at 20 °C air temperature. In particular, at 20 °C air temperature, arteriovenous anastomoses (AVAs) might be closed at baseline, as finger skin temperature was much lower than at 25 °C air temperature, and endothelial NO-independent activity was significantly higher and neurogenic activity significantly lower during vasoconstriction than at baseline. Additionally, the differences in both activities between vasoconstriction and prior to CIVD were significant. On the other hand, there were no significant differences in endothelial NO-dependent activity between baseline and all phases at both air temperatures. CONCLUSIONS: Our results indicated that the increase of endothelial NO-independent activity and the decrease of neurogenic activity may contribute to the high increment ratio of blood flow at CIVD at 20 °C air temperature.


Assuntos
Temperatura Baixa , Dedos/irrigação sanguínea , Vasodilatação/fisiologia , Adolescente , Adulto , Anastomose Arteriovenosa/fisiologia , Feminino , Humanos , Masculino , Análise de Ondaletas , Adulto Jovem
7.
Adv Respir Med ; 88(5): 458-461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33169820

RESUMO

Massive hemoptysis is a serious medical condition or emergency which needs immediate treatment. It typically appears in the bronchial arteries and can be caused by a wide range of pulmonary diseases. This report is based on a very rare case of a patient bleeding from an anastomosis between the left phrenic artery and pulmonary arteries/veins. In this case, the chest computed tomography had detected changes which required doctors to perform a successful embolization.


Assuntos
Anastomose Arteriovenosa , Artérias Brônquicas , Hemoptise , Artéria Pulmonar , Artérias Brônquicas/anormalidades , Embolização Terapêutica , Hemoptise/etiologia , Humanos , Artéria Pulmonar/anormalidades
9.
J Appl Physiol (1985) ; 129(6): 1341-1347, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33054656

RESUMO

The utility of transthoracic saline contrast echocardiography (TTSCE) to assess blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA) in humans is limited due to the potential destabilizing effects of the gas concentration gradients established in varied blood-gas environments. This study assessed the specific effect of a hyperoxic and mixed venous blood-gas environment on the stability of saline contrast. We hypothesized that the rate of contrast mass lost in hyperoxic blood would be similar to mixed venous due to the establishment of equal and opposing gas gradients (O2, N2, CO2) created when the partial pressure of dissolved gases is manipulated. Using an in vitro model of the pulmonary circulation perfused with defibrinated sheep blood and a membrane oxygenator to control blood gases, we assessed the percent contrast conserved (an index of contrast stability) between inflow and outflow sites at multiple flow rates (1.8, 2.8, 4.3, and 6.8 L/min) in a hyperoxic (Po2: 646 ± 16 mmHg; Pco2: 0 ± 0 mmHg) and a mixed venous blood gas condition (Po2: 35 ± 3 mmHg; Pco2: 40 ± 0 mmHg). We found significant contrast decay with time in both conditions, with slightly higher contrast conservation in the hyperoxia trials (64 ± 32%) versus the mixed venous trials (55 ± 21%). These findings suggest that contrast stability is not likely a factor affecting the interpretation of TTSCE performed in healthy humans breathing hyperoxia and lends support to the existence of a local O2-dependent mechanism contributing to the regulation of Q̇IPAVA.NEW & NOTEWORTHY Hyperoxic blood has a small stabilizing effect on agitated saline contrast compared with mixed venous blood, lending support to studies that show the reversal of exercise-induced blood flow through intrapulmonary arteriovenous anastomoses (Q̇IPAVA) with hyperoxia. These data support the possible presence of a local O2-dependent regulatory mechanism within the pulmonary vasculature that may play a role in Q̇IPAVA regulation.


Assuntos
Anastomose Arteriovenosa , Hiperóxia , Animais , Anastomose Arteriovenosa/diagnóstico por imagem , Ecocardiografia , Hemodinâmica , Oxigênio , Circulação Pulmonar , Ovinos
10.
Neurocirugía (Soc. Luso-Esp. Neurocir.) ; 31(5): 209-215, sept.-oct. 2020. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-195153

RESUMO

BACKGROUND: Normal perfusion pressure breakthrough (NPPB) phenomenon is a major life-threatening complication that restricts the treatment of complex intracranial arteriovenous malformations. The aim of the study it to develop a rat model mimicking NPPB phenomenon that enables the evaluation of any therapy to prevent such complication. METHODS: Twenty Wistar male rats were randomly assigned to either a study or a control group. Study animals underwent an end-to-side left external jugular vein-common carotid artery anastomosis and ligation of bilateral external carotid arteries. Control animals only underwent ligation of bilateral external carotid arteries. All animals were sacrificed sixty days after the procedure. Hemodynamic parameters [mean arterial pressure (MAP), intracranial pressure (ICP) and cerebral perfusion pressure (CPP)], blood-brain barrier (BBB) permeability (measured by fluorescein staining) and histological features were then compared between both groups. RESULTS: A significant decrease in MAP and CPP was confirmed in the study group. An increase in ICP was also observed. A significant decrease in MAP and CPP was also present in the study group when comparing preoperative values with those recorded on days 0 (postoperative), 7 and 60. Fluorescein staining findings were consistent with signs of BBB disruption in study animals. Histological analysis demonstrated an increased number of pyknotic neurons in the ipsilateral hemisphere of rat brains included in the study group. CONCLUSION: These results confirm that this model mimics a vascular steal state with chronic cerebral hypoperfusion comparable to patients with AVMs behavior and disruption of the BBB after fistula closure comparable to NPPB phenomenon disorders


INTRODUCCIÓN: El síndrome de restablecimiento de la presión de perfusión cerebral (PPC) normal es una complicación grave, que supone un riesgo vital y limita el tratamiento de malformaciones arteriovenosas complejas. El objetivo de este estudio es desarrollar un modelo animal remedando dicho síndrome que permita evaluar terapias para su prevención. MÉTODOS: Veinte ratas macho Wistar fueron asignadas aleatoriamente a un grupo estudio o control. Los animales de estudio se sometieron a una anastomosis término-lateral entre la vena yugular externa y la arteria carótida común izquierdas y ligadura bilateral de las arterias carótidas externas. Los animales control se sometieron a la ligadura bilateral de las arterias carótidas externas. Todos los animales se sacrificaron 60 días después. Se compararon parámetros hemodinámicos (presión arterial media [PAM], presión intracraneal [PIC] y PPC), permeabilidad de la barrera hemato-encefálica (BHE) y características histológicas entre ambos grupos. RESULTADOS: El grupo estudio mostró un descenso significativo de la PAM y la PPC, así como un aumento de la PIC respecto al grupo control. Al comparar los valores preoperatorios con aquéllos registrados los días 0 (postoperatorio), 7 y 60 en el grupo estudio, también se confirmó un descenso significativo de la PAM y la PPC. La disrupción de la BHE fue constatada únicamente en el grupo estudio mediante la extravasación de fluoresceína sódica. El análisis histológico demostró mayor número de neuronas picnóticas en el hemisferio ipsilateral a la anastomosis de los animales estudio. CONCLUSIÓN: Los resultados descritos apuntan a un modelo que remeda el estado de robo vascular con hipoperfusión cerebral crónica comparable al que sufren los pacientes con malformaciones arteriovenosas, así como la disrupción de la BHE tras el cierre de la anastomosis, comparable al acontecido en el síndrome de restablecimiento de la PPC normal tras la exclusión de la malformación


Assuntos
Animais , Masculino , Ratos , Malformações Arteriovenosas Intracranianas/terapia , Pressão Intracraniana , Modelos Animais , Malformações Arteriovenosas Intracranianas/veterinária , Ratos Wistar , Anastomose Arteriovenosa , Ligadura/veterinária , Monitorização Hemodinâmica/veterinária
11.
Biomed Res Int ; 2020: 6352939, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32724804

RESUMO

Background: In microvascular anastomosis, size discrepancy is common and can increase thrombotic complications. If size differences can be predicted, then vessels of the appropriate size can be selected. This study documented the difference in diameter between the thoracodorsal (TD) vessel and deep inferior epigastric perforator (DIEP) pedicle in each patient who underwent breast reconstruction using free tissue transfer. Patients and Methods. This retrospective study included 32 anastomoses (27 breasts including five cases of supercharged anastomosis) of breast reconstruction with the free DIEP flap and TD recipient between August 2018 and June 2019. In the microscopic view, the caliber of the TD vessel, the largest branch to the serratus anterior muscle, the descending branch, the largest and the second largest branches to the latissimus dorsi muscle, and the DIEP pedicle were measured. Results: The diameter of the deep inferior epigastric artery was similar to that of the descending branch, and their anastomosing rate was 56.3%. The diameter of the deep inferior epigastric vein was similar to the branch to the serratus anterior muscle and the descending branch, and their anastomosing rates were 29.3% and 29.3%, respectively. All flaps were survived; however, in one case, a reoperation was needed to remove the hematoma, in which case fat necrosis occurred as the only complication. Conclusion: TD branches of similar size to the DIEP pedicle were prioritized in anastomosis. The descending branch and the branch to the serratus anterior muscle are expected to be good candidates as recipients in breast reconstruction with DIEP free flap. Moreover, supercharged anastomosis of DIEP pedicles can be achieved within TD branches.


Assuntos
Anastomose Arteriovenosa/fisiologia , Mama/fisiologia , Mama/cirurgia , Anastomose Cirúrgica/métodos , Feminino , Humanos , Mamoplastia/métodos , Mastectomia/métodos , Pessoa de Meia-Idade , Retalho Perfurante/fisiologia , Retalho Perfurante/cirurgia , Complicações Pós-Operatórias/fisiopatologia , Reoperação/métodos , Estudos Retrospectivos , Resultado do Tratamento
12.
Placenta ; 95: 84-90, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32452406

RESUMO

INTRODUCTION: Three-dimensional (3D) sonography combined with tomographic ultrasound imaging (TUI) to observe placental vascular anastomoses in monochorionic diamniotic (MCDA) twin pregnancies was evaluated. METHODS: Women with MCDA twin pregnancies at a gestational age of 16-32 weeks were enrolled in this retrospective study. Placental anastomoses were detected using two-dimensional (2D) and 3D sonography. Two-dimensional data were obtained by color and spectral Doppler and 3D data with high-definition flow within the area between twins' umbilical cord insertions. Volume post-processing using TUI mode identified anastomoses. Anastomotic findings on ultrasound were compared with fetoscopic surgery or postnatally injected placentas for diagnostic value. Anastomoses detection was compared between the two imaging modalities. RESULTS: Seventy-six twin pregnancies were analyzed: 11 selective intrauterine growth restrictions (sIUGR), 10 twin-to-twin transfusion syndrome (TTTS), and 55 without complications. Seventy-one twin pregnancies had arterio-arterial (AA) anastomoses and 75 had arterio-venous (AV) anastomoses. Three-dimensional sonography combined with TUI was more sensitive (87.3%) and accurate (88.2%) in detecting AA anastomoses than 2D sonography (74.6%, 76.3%, respectively; P < 0.05), but had comparable sensitivity for AV anastomoses. The specificity of both modalities for anastomoses was 100%. The detection rate of AA anastomoses by 3D modality was (40%) TTTS vs. (87.3%) normal (P < 0.05), but comparable (90.9%) for sIUGR. The detection rates of AV anastomoses (90%, 81.8%) in TTTS and sIUGR were comparable with (87.3%) normal (P > 0.05). DISCUSSION: Three-dimensional sonography combined with TUI highlighted placental anastomoses and may be useful for the clinical diagnosis and therapy of MCDA twin complications.


Assuntos
Anastomose Arteriovenosa/diagnóstico por imagem , Retardo do Crescimento Fetal/diagnóstico por imagem , Transfusão Feto-Fetal/diagnóstico por imagem , Placenta/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Adulto , Feminino , Humanos , Placenta/irrigação sanguínea , Gravidez , Estudos Retrospectivos
14.
Prenat Diagn ; 40(10): 1284-1289, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32412655

RESUMO

OBJECTIVE: To compare the prevalence of intermittent absent or reversed end-diastolic flow (iAREDF) in the umbilical artery in appropriately grown monochorionic diamniotic (MCDA) pregnancies with and without proximate cord insertion (PCI), and to evaluate pregnancy outcome. METHODS: The prevalence of iAREDF in MCDA pregnancies with PCI (n = 11) was compared with a control group without PCI (n = 33). PCI was defined as a distance between the cord insertions below the fifth percentile. Placental sharing, number, and diameter of anastomoses were assessed by placental examination. Pregnancy outcome was evaluated. RESULTS: iAREDF was present in 7/11 PCI pregnancies, compared with 0/33 in the control group (P ≤ .01). All PCI pregnancies and 94% of controls had arterioarterial (AA)-anastomoses (P = .56), the diameter was larger in the PCI group, respectively 3.3 vs 2.1 mm (P = .03). Three cases with iAREDF had adverse outcome, two resulted in fetal death of which one with brain damage in the co-twin, another underwent early premature emergency section for fetal distress. CONCLUSION: iAREDF occurs in a large proportion of MCDA pregnancies with PCI and is related to the diameter of the AA anastomosis. We hypothesize that iAREDF in appropriately grown MCDA twin pregnancies reflects an unstable hemodynamic balance with an increased risk for fetal deterioration. Whether outcome in these pregnancies can be improved by altered management requires further investigation.


Assuntos
Anormalidades Cardiovasculares/epidemiologia , Resultado da Gravidez/epidemiologia , Gravidez de Gêmeos , Artérias Umbilicais/anormalidades , Cordão Umbilical/patologia , Adulto , Anastomose Arteriovenosa/patologia , Anastomose Arteriovenosa/fisiologia , Anormalidades Cardiovasculares/diagnóstico , Anormalidades Cardiovasculares/fisiopatologia , Estudos de Casos e Controles , Feminino , Morte Fetal/etiologia , Retardo do Crescimento Fetal/diagnóstico , Retardo do Crescimento Fetal/epidemiologia , Retardo do Crescimento Fetal/etiologia , Humanos , Países Baixos/epidemiologia , Placenta/anormalidades , Placenta/irrigação sanguínea , Placenta/patologia , Gravidez , Gravidez de Gêmeos/estatística & dados numéricos , Prevalência , Fluxo Sanguíneo Regional , Gêmeos Monozigóticos/estatística & dados numéricos , Artérias Umbilicais/patologia , Artérias Umbilicais/fisiopatologia , Cordão Umbilical/fisiopatologia
15.
J Perinat Med ; 48(6): 539-543, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32304312

RESUMO

Objectives To evaluate the impact of placental anastomoses on the intrauterine growth of monochorionic (MC) twins. Methods A prospective study was conducted in a group of 53 MC twins. Intrapartally umbilical cords were clamped to identify placental sides corresponding to each twin. The postnatal dye injection technique was administered to evaluate vascular anastomoses, their number and type and visualize placental territory sharing patterns. Data from digital analysis were correlated with obstetrical follow-up. Results Vascular anastomoses were revealed in 88.7% of cases. Arteriovenous (AV) anastomoses occurred in 75.4% and arterioarterial (AA) in 71.1% while venovenous (VV) in 26.4%. In the subgroup of MC twins without placental anastomoses, significantly higher birthweight difference and discordance were revealed when compared to MC twins without anastomoses (382.0 vs. 22 g; P = 0.03 and 49.14% vs. 16.02%; P = 0.03). On the other hand, in subgroups of MC twins with at least one AA anastomosis, twins' birthweights were similar (p = ns) despite significantly higher placental territory sharing discordance (30.44% vs. 15.81%; P = 0.31). Conclusions Vascular anastomoses have a major impact on the intrauterine growth of MC twins. In certain cases, they may cause specific complications; however, in general, they regulate intertwin blood exchange and may compensate unequal placental territory.


Assuntos
Anastomose Arteriovenosa/fisiopatologia , Desenvolvimento Fetal/fisiologia , Placenta/irrigação sanguínea , Gravidez de Gêmeos , Adulto , Peso ao Nascer , Cesárea/estatística & dados numéricos , Córion , Parto Obstétrico , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Nascimento Prematuro/epidemiologia , Estudos Prospectivos , Técnicas de Reprodução Assistida/estatística & dados numéricos
16.
Artigo em Alemão | MEDLINE | ID: mdl-32069480

RESUMO

Children and adolescents with disabilities have the right of full and effective participation and inclusion in society. Disability includes a wide range of long-term physical, mental, intellectual and sensory impairments for various reasons. In addition to the basic illness many children with disabilities have concomitant diseases. These diseases are decisive for the perioperative risk. Information from parents regarding their child's behavioural patterns and needs, signs of escalating anxiety and pain are important. Perioperative dialog with the parents is helpful and has positive effects also from parental point of view. Pharmacologic premedication is recommended. Induction of anaesthesia can be challenging and sometimes requires unconventional methods. Pain behaviour may be unusual. There are suitable scales that incorporate such behaviours.


Assuntos
Ansiedade , Anastomose Arteriovenosa , Pessoas com Deficiência , Adolescente , Criança , Humanos , Dor , Pais
17.
Anat Histol Embryol ; 49(5): 585-596, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31774212

RESUMO

Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway.


Assuntos
Vasos Sanguíneos/crescimento & desenvolvimento , Macrófagos/fisiologia , Receptores de TIE/metabolismo , Animais , Anastomose Arteriovenosa/fisiologia , Vasos Sanguíneos/fisiologia , Humanos , Remodelação Vascular/fisiologia
18.
Int Wound J ; 17(1): 107-116, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31668019

RESUMO

Free flaps in combination with arterial reconstruction by means of arteriovenous loops or bypass have, meanwhile, been established as a therapeutic option in defect reconstruction for areas without recipient vessels. Our aim was to analyse the long-term performance, flap autonomy, and the flap perfusion. Patients receiving this combined reconstruction at a single-centre institution were included. During follow-up examination, the patency of arterial reconstruction was investigated by duplex ultrasound. Flap micro-circulation was assessed by laser Doppler flowmetry and white light tissue spectrometry (O2C) as well as by indocyanine green fluorescence angiography. Twenty-three patients could be clinically followed up. Duplex ultrasound showed, in four cases, arterial pedicle occlusion in spite of vital flap. Comparison of the O2C perfusion parameters between flaps with occluded pedicles and those with intact inflow showed no significant difference (parameters sO2: P = .82; Flow: P = .31). Similar results were obtained by fluorescence angiography; no significant difference could be detected between both groups (parameters Ingress P = .13; Ingressrate P = .54). Combined vascular reconstruction with free tissue transfer is associated with a good long-term outcome and wound closure. Even after flap transplantation to areas with critical tissue perfusion, the flap can develop autonomy and thus survive after pedicle occlusion.


Assuntos
Anastomose Arteriovenosa/cirurgia , Retalhos de Tecido Biológico/cirurgia , Procedimentos Cirúrgicos Reconstrutivos/métodos , Cicatrização/fisiologia , Ferimentos e Lesões/cirurgia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
19.
Blood Purif ; 49(1-2): 16-24, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31536984

RESUMO

BACKGROUND: Arteriovenous fistulas (AVF) have been the main vascular accesses for haemodialysis patients, but the maintenance after maturation poses serious challenges. Arm exercises promote the maturation of AVFs. However, few studies have evaluated the effect of arm exercise on matured AVF and addressed the intervention for late fistula failure. OBJECTIVES: The study was conducted to explore the effect of dumbbell exercise on mature AVF. METHODS: 86 participants undergoing haemodialysis with AVFs were randomized into the control group and experimental group. The experimental group held 6-pound dumbbells on non-dialysis days for 3 months, while the control group squeezed rubber balls. RESULTS: For blood flow of draining vein (DV; primary outcome), the between-group effects, interaction effect and time effect showed significant differences. A significant increase in blood flow of DV was observed in the dumbbell group at the 3rd month (mean difference, 359.50 [111.90-829.05] mL/min; p = 0.001). The difference in blood flow of AVF proximal artery, blood flow of brachial artery, the diameter of DV and the incidence of adverse events at 3 months (secondary outcomes) between the 2 groups was insignificant. CONCLUSION: Prolonged training with arm exercises is essential for patients with AVFs though the fistula has matured. The designed dumbbell exercise is an economical, effective intervention to maintain the function of AVF, especially for patients with potential reduction of access blood flow and no percutaneous transluminal angioplasty indication.


Assuntos
Artéria Braquial/fisiopatologia , Exercício Físico , Diálise Renal , Adulto , Idoso , Anastomose Arteriovenosa , Velocidade do Fluxo Sanguíneo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
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