228 resultados para vascular hemodynamics
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The aim of this study was to demonstrate that the prevention of early scaffold area shrinkage of the ABSORB BVS (Rev.1.1, Abbott Vascular, Santa Clara, California) was sustained and not simply delayed by a few months.
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The aim of this study was to compare the angiographic changes in coronary geometry of the bioresorbable vascular scaffolds (BVS) and metallic platform stent (MPS) between baseline and follow-up.
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We investigated the 6-month clinical outcomes after implantation of second-generation 3.0-mm bioresorbable everolimus-eluting vascular scaffolds (BVS) in small coronary vessels (<2.5 mm).
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To compare the intravascular ultrasound virtual histology (IVUS-VH) appearance of the polymeric struts of the first (Revision 1.0) and the second (Revision 1.1) generation bioresorbable vascular scaffold (BVS).
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The vascular tissue reaction to acute incomplete stent apposition (ISA) is not well known. The aim of this study was to characterize the vascular response to acute ISA in vivo and to look for predictors of incomplete healing.
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Chronic mountain sickness (CMS) is a major public health problem characterized by exaggerated hypoxemia and erythrocytosis. In more advanced stages, patients with CMS often present with functional and structural changes of the pulmonary circulation, but there is little information on the systemic circulation. In patients with diseases associated with chronic hypoxemia at low altitude, systemic vascular function is altered. We hypothesized that patients with CMS have systemic vascular dysfunction that may predispose them to increased systemic cardiovascular morbidity.
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This study sought to investigate the feasibility and safety of percutaneous management of vascular complications after transcatheter aortic valve implantation (TAVI).
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New theories on the regeneration of ischemic vasculature have emerged indicating a pivotal role of adult stem cells. The aim of this study was to investigate homing and hemodynamic effects of circulating bone marrow-derived mesenchymal stem cells (MSCs) in a critically ischemic murine skin flap model. Bone marrow-derived mesenchymal stem cells (Lin(-)CD105(+)) were harvested from GFP(+)-donor mice and transferred to wildtype C57BL/6 mice. Animals receiving GFP(+)-fibroblasts served as a control group. Laser scanning confocal microscopy and intravital fluorescence microscopy were used for morphological analysis, monitoring and quantitative assessment of the stem cell homing and microhemodynamics over two weeks. Immunohistochemical staining was performed for GFP, eNOS, iNOS, VEGF. Tissue viability was analyzed by TUNEL-assay. We were able to visualize perivascular homing of MSCs in vivo. After 4 days, MSCs aligned along the vascular wall without undergoing endothelial or smooth muscle cell differentiation during the observation period. The gradual increase in arterial vascular resistance observed in the control group was abolished after MSC administration (P<0.01). At capillary level, a strong angiogenic response was found from day 7 onwards. Functional capillary density was raised in the MSC group to 197% compared to 132% in the control group (P<0.01). Paracrine expression of VEGF and iNOS, but not eNOS could be shown in the MSC group but not in the controls. In conclusion, we demonstrated that circulating bone marrow-derived MSCs home to perivascular sites in critically ischemic tissue, exhibits paracrine function and augment microhemodynamics. These effects were mediated through arteriogenesis and angiogenesis, which contributed to vascular regeneration.
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Notch signaling mediates embryonic vascular development and normal vascular remodeling; Notch1 knockout mice develop nodular regenerative hyperplasia (NRH). The pathogenesis of NRH is unclear, but has been associated with vascular injury in the liver sinusoids in clinical studies. We investigated the role of Notch1 signaling in liver sinusoidal endothelial cells (LSECs).
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Since the initial work of Jacobson and Suarez in 1960, microsurgery has evolved greatly. In 2009, we reported our clinical experience with 1.9 µm diode laser-assisted vascular microanastomoses (LAMA) for free flap reconstruction. In this report, the ongoing study is now expanded to include 11 additional procedures which were analyzed prospectively with a focus on the duration of the LAMA technique.
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Microvascular surgery has become an important method for reconstructing surgical defects due to trauma, tumors or after burn. The most important factor for successful free flap transfer is a well-executed anastomosis. The time needed to perform the anastomosis and the failure rate are not negligible despite the high level of operator's experience. During the history, many alternatives were tried to help the microsurgeon and to reduce the complications. A Medline literature search was performed to find articles dealing with non-suture methods of microvascular anastomosis. Many historical books were also included. The non-suture techniques can be divided into four groups based on the used mechanism of sutures: double intubation including tubes and stents, intubation-eversion including simple rings, double eversion including staples and double rings, and wall adjustement with adhesives or laser. All these techniques were able to produce a faster and easier microvascular anastomosis. Nevertheless, disadvantages of the suturless techniques include toxicity, high cost, leakage or aneurysm formation. More refinement is needed before their widespread adoption. Thus, laser-assisted microvascular anastomosis using 1,9 μm diode laser appeared to be a safe and reliable help for the microsurgeon and may be further developed in the near future.
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Arts speech therapy (AST) is a therapeutic method within complementary medicine and has been practiced for decades for various medical conditions. It comprises listening and the recitation of different forms of speech exercises under the guidance of a licensed speech therapist. The aim of our study was to noninvasively investigate whether different types of recitation influence hemodynamics and oxygenation in the brain and skeletal leg muscle using near-infrared spectroscopy (NIRS). Seventeen healthy volunteers (eight men and nine women, mean age ± standard deviation 35.6 ± 12.7 years) were enrolled in the study. Each subject was measured three times on different days with the different types of recitation: hexameter, alliteration, and prose verse. Before, during, and after recitation, relative concentration changes of oxyhemoglobin (Δ[O2Hb]), deoxyhemoglobin (Δ[HHb]), total hemoglobin (Δ[tHb]), and tissue oxygenation saturation (StO2) were measured in the brain and skeletal leg muscle using a NIRS device. The study was performed with a randomized crossover design. Significant concentration changes were found during recitation of all verses, with mainly a decrease in Δ[O2Hb] and ΔStO2 in the brain, and an increase in Δ[O2Hb] and Δ[tHb] in the leg muscle during recitation. After the recitations, significant changes were mainly increases of Δ[HHb] and Δ[tHb] in the calf muscle. The Mayer wave spectral power (MWP) was also significantly affected, i.e., mainly the MWP of the Δ[O2Hb] and Δ[tHb] increased in the brain during recitation of hexameter and prose verse. The changes in MWP were also significantly different between hexameter and alliteration, and hexameter and prose. Possible physiological explanations for these changes are discussed. A probable reason is a different effect of recitations on the sympathetic nervous system. In conclusion, these changes show that AST has relevant effects on the hemodynamics and oxygenation of the brain and muscle.