Microvascular research
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Microvascular research · May 2017
Randomized Controlled TrialReduced perfusion in systemic sclerosis digital ulcers (both fingertip and extensor) can be increased by topical application of glyceryl trinitrate.
In patients with systemic sclerosis (SSc), fingertip digital ulcers (DUs) are believed to be ischaemic, and extensor surface DUs a result of mechanical factors/microtrauma. Our aim was to assess blood flow response to topical glyceryl trinitrate (GTN) compared to placebo in SSc DUs, looking for differences in pathophysiology between fingertip and extensor lesions. ⋯ DUs (both fingertip and extensor) were responsive to topical GTN, with an increase in perfusion to the ischaemic DU centre. If both fingertip and extensor DUs have a (potentially reversible) ischaemic aetiology, this has important treatment implications.
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Microvascular research · May 2017
Changes in vascular responsiveness during a hyperglycemia challenge measured by near-infrared spectroscopy vascular occlusion test.
Postprandial hyperglycemia is associated with impaired vascular responsiveness. Recent studies have established the use of a near-infrared spectroscopy (NIRS)-derived approach, combined with a vascular occlusion test (VOT), to examine vascular responsiveness within the microvasculature in normoglycemia. The aim of this study was to examine whether this NIRS-VOT technique could detect differences in vascular responsiveness following a hyperglycemic challenge. ⋯ This study showed that the NIRS-VOT technique is capable of detecting differential changes in vascular responsiveness to a hyperglycemic challenge, as indicated by a steeper Slope 2 StO2 and decreased StO2AUC following 90min of an oral glucose challenge.
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Microvascular research · Mar 2017
Plasma endothelial microparticles reflect the extent of capillaroscopic alterations and correlate with the severity of skin involvement in systemic sclerosis.
Endothelial microparticles (EMPs) are membrane-coated vesicles shed from endothelial cells and are considered markers of the endothelial state. It has been shown that total numbers of circulating EMPs are increased in patients with systemic sclerosis (SSc), but their clinical correlations have not yet been investigated in detail. We aimed to assess possible relationships between circulating EMPs and clinical as well as laboratory features among SSc patients with special attention to possible association with alteration in microvascular morphology objectified on nailfold videocapillaroscopy and clinical signs of microvascular complications. ⋯ Our results suggest that quantity and phenotype of circulating EMPs might indicate on molecular vascular damage with endothelial dysfunction and to reflect progressive loss of capillaries consequencing in microvascular insufficiency in SSc patients.
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Microvascular research · Mar 2017
Comparative StudyLaser speckle contrast imaging and Oxygen to See for assessing microcirculatory liver blood flow changes following different volumes of hepatectomy.
Portal hyperperfusion after extended hepatectomy or small-for-size liver transplantation may induce organ dysfunction and failure. This study was designed to monitor and characterize the hepatic microcirculatory perfusion following different volumes of hepatectomy in rats by using laser speckle contrast image (LSCI) and Oxygen to See (O2C), a spectrometric device. ⋯ Hepatic microcirculation hyperperfusion resulting from major and extended liver resection could be assessed by LSCI and O2C methods. The 90PH in rats led to extraordinary sinusoidal hyperperfusion, severe endothelial injury and liver failure. Monitoring the changes of hepatic microcirculation perfusion following extended hepatectomy or small-for-size liver transplantation may help to analyze the extent of hyperperfusion.
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Microvascular research · Mar 2017
In systemic sclerosis skin perfusion of hands is reduced and may predict the occurrence of new digital ulcers.
Systemic sclerosis (SSc) patients are at high risk for the development of ischemic digital ulcers (DUs). The aim of this study was to assess in SSc patients a correlation between skin perfusion evaluated by LDPI and DUs and to evaluate the prognostic value of skin perfusion to predict the new DUs occurrence. Fifty eight (47 female, 11 male) SSc patients were enrolled. ⋯ The ROC curves demonstrated a good accuracy of new DUs prediction for PDG (0.78, p<0.0001). Using this cut-off value of 30 pU, RR for new DUs development in SSc patients without PDG is 4,2 (p<0.001). LDPI indices could be used in association to the capillaroscopic and clinical findings or serological tests in the identification of patients at high risk of developing DUs.