Clinical Hemorheology and Microcirculation - Volume 74, issue 2

Authors: Chayer, Boris | Allard, Louise | Qin, Zhao | Garcia-Duitama, Julian | Roger, Laurence | Destrempes, François | Cailhier, Jean-François | Denault, André | Cloutier, Guy

Article Type: Research Article

Abstract: BACKGROUND: An enhanced inflammatory response is a trigger to the production of blood macromolecules involved in abnormally high levels of erythrocyte aggregation. OBJECTIVE: This study aimed at demonstrating for the first time the clinical feasibility of a non-invasive ultrasound-based erythrocyte aggregation quantitative measurement method for potential application in critical care medicine. METHODS: Erythrocyte aggregation was evaluated using modeling of the backscatter coefficient with the Structure Factor Size and Attenuation Estimator (SFSAE). SFSAE spectral parameters W (packing factor) and D (mean aggregate diameter) were measured within the antebrachial vein of the forearm and tibial vein …of the leg in 50 healthy participants at natural flow and reduced flow controlled by a pressurized bracelet. Blood samples were also collected to measure erythrocyte aggregation ex vivo with an erythroaggregometer (parameter S 10 ). RESULTS: W and D in vivo measurements were positively correlated with the ex vivo S 10 index for both measurement sites and shear rates (correlations between 0.35–0.81, p  < 0.05). Measurement at low shear rate was found to increase the sensitivity and reliability of this non-invasive measurement method. CONCLUSIONS: We behold that the SFSAE method presents systemic measures of the erythrocyte aggregation level, since results on upper and lower limbs were highly correlated. Show more

Keywords: Erythrocyte aggregation, quantitative ultrasound, shear rate control, human, clinical measurements

DOI: 10.3233/CH-180541

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 109-126, 2020

Authors: Wang, S. | Li, B. | Yin, T. | Hong, J. | Gu, J. | Wei, L.

Article Type: Research Article

Abstract: BACKGROUND: The aneurysmal subarachnoid hemorrhage (aSAH) is an acute severe hemorrhagic stroke with high morbidity and mortality with poor prognosis. OBJECTIVE: This study aims to analyze the changes of cerebral venous circulation in patients with aneurysmal subarachnoid hemorrhage by digital subtraction angiography (DSA). MATERIALS AND METHODS: Totally, 57 patients with aSAH, 48 patients with unruptured aneurysms, and 45 patients without aneurysms (control group) were enrolled. The microvascular cerebral circulation time (mCCT), venous cerebral circulation time (vCCT), cerebral arterioles and cortical veins were analyzed by DSA. RESULTS: There were changes of cerebral microvessels and cortical …veins in patients with aSAH. The mCCT (6.15±1.37 s) and vCCT (2.79±0.34 s) of aSAH patients significantly increased compared with control patients (3.74±0.50 s; 2.64±0.32 s) (P  < 0.05). However, the mCCT increased more compared with vCCT in aSAH patients (P  < 0.001), while the vCCT increased more compared with mCCT in severe aSAH cases (P  < 0.01). There was no significant difference in mCCT and vCCT between patients with unruptured aneurysms and controls (P  = 0.131; P  = 0.621). CONCLUSIONS: The mCCT increases in acute aSAH patients within 72 hours and vCCT increases in severe aSAH cases. Show more

Keywords: Aneurysmal subarachnoid hemorrhage, cerebral vein, digital subtraction angiography, microvascular cerebral circulation time, venous cerebral circulation time

DOI: 10.3233/CH-190573

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 127-138, 2020

Authors: Vosseler, Markus | El Shazly, Ahmed | Parker, John D. | Münzel, Thomas | Gori, Tommaso

Article Type: Research Article

Abstract: BACKGROUND: Evidence of a circadian rhythm in endothelium-dependent vasomotor function, with a nadir in Flow-Mediated Dilation (FMD) in the early morning hours, has been previously reported. These changes have been proposed to be one of the mechanisms explaining the circadian pattern in the incidence of cardiovascular events. We set out to investigate the circadian rhythm of FMD, low-flow mediated dilation (L-FMC) and sympathetic vascular tone. METHODS AND RESULTS: 10 young healthy male volunteers (mean age, 28.9±3.7 years) underwent measurements of radial artery endothelium-dependent FMD and L-FMC at 8AM, 2PM and 8PM on the same day. Sympathetic vascular tone …was assessed with laser Doppler and Fourier transform analysis. Compared with 2PM and 8PM, FMD decreased markedly in the early morning (2.9±3.4%; 6.2±2.9%; 6.0±4.0%; P  = 0.007). In contrast, L-FMC was maximal at 8AM, decreased significantly at 2PM, and returned to higher values at 8PM (–5.1±1.3%; –2.7±2.0%; –4.6±2.2%; P  = 0.030), such that the composite endpoint of endothelial function (sum of FMD+L-FMC) was not significantly different among timepoints. Vascular sympathetic tone was maximal early in the morning and lowest in the evening (P  = 0.014) without a correlation with the changes in FMD or L-FMC. CONCLUSIONS: Endothelial responsiveness (FMD) and basal tone (L-FMC) appear to follow different circadian rhythms, with an impaired responsiveness in the early morning and a nadir in baseline tone in the early afternoon. Show more

Keywords: Endothelial function, circadian rhythm, vascular physiology

DOI: 10.3233/CH-190587

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 139-146, 2020

Authors: Sabra, Ahmed | Lawrence, Matthew J. | Curtis, Dan | Hawkins, Karl | Williams, Phylip R. | Evans, Phillip A.

Article Type: Research Article

Abstract: INTRODUCTION: This aim of this study is to investigate the individual effects of varying concentrations of thrombin and fibrinogen on clot microstructure (characterised through the fractal dimension of the incipient clot network, d f ) and clot formation time (T GP ) using a fibrin-thrombin clot model. d f and T GP markers are measured using a haemorheological method that has already been investigated for whole blood. METHODS: This is an in vitro study using three thrombin concentrations (0.1, 0.05 and 0.02 NIH/ml) and two fibrinogen concentrations (8 mg/ml and 12 mg/ml) to …investigate a fibrin-thrombin clot model. The haemorheological changes were measured at the gel point using d f and T GP . RESULTS: Fractal dimension (d f ) increased with increasing concentrations of thrombin both at 8 mg/ml (1.60±0.024, 1.67±0.022, 1.74±0.079) and 12 mg/ml fibrinogen concentrations (1.63±0.02, 1.87±0.019, 1.95±0.014). On the other hand, T GP decreased for both 8 mg/ml (1089±265, 637±80, 223±22 seconds) and 12 mg/ml fibrinogen concentrations (2008±247, 776±20, 410±20 seconds). In contrast to previous studies investigating whole blood, T GP increased with higher fibrinogen levels. CONCLUSIONS: The findings from this fibrin-thrombin clot model confirmed that d f and T GP can detect changes in the incipient clot following manipulation of fibrinogen and thrombin concentration. d f increases (indicating stronger clot) with higher concentrations of thrombin and fibrinogen. On the other hand, T GP decreased as expected with higher thrombin level but not with higher fibrinogen concentrations. Show more

Keywords: Thrombin, fibrinogen, clot microstructure, fractal dimension

DOI: 10.3233/CH-190615

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 147-153, 2020

Authors: Ederer, I.A. | Goertz, O. | Bosselmann, T. | Sogorski, A. | Zahn, P.K. | Lehnhardt, M. | Daigeler, A. | Kolbenschlag, J.

Article Type: Research Article

Abstract: BACKGROUND: Mechanism of remote ischemic conditioning (RIC) remain not fully understood yet. Thus, a clinical trial was performed to assess the neuronal influence on its signal induction. METHODS: RIC was conducted on 45 patients who were randomized into 3 groups. Group A and B underwent brachial plexus anesthesia while RIC was performed on the blocked (A) and non-blocked side (B), respectively. In group C, RIC was conducted before regional anesthesia, thus serving as control group. All measurements were taken contralateral to RIC. The relative increase of microcirculatory parameters compared to baseline was evaluated and compared between the groups. …RESULTS: Superficial blood flow (sBF) significantly increased in group A and C but values were higher among group C. Compared to group A, group C showed a significant increase of sBF during the initial 5 minutes of reperfusion (1.75; CI 1.139 – 2.361 vs . 0.97, CI 0.864 – 1.076, p  < 0.05). Deep blood flow, tissue oxygen saturation and relative hemoglobin content were marginally influenced by RIC irrespectively of the presence of regional anesthesia. CONCLUSION: Despite regional anesthesia a significant RIC stimulus can be induced although its microcirculatory response is attenuated compared to control. Hence, RIC induction does not merely depend on neuronal signaling. Show more

Keywords: Remote ischemic conditioning, neuronal signaling, plexus anesthesia, microsurgery, reperfusion

DOI: 10.3233/CH-190626

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 155-166, 2020

Authors: Dong, Yi | Liu, Lingxiao | Cao, Qiong | Zhang, Qi | Qiu, Yijie | Yang, Daohui | Yu, Lingyun | Wang, Wen-Ping

Article Type: Research Article

Abstract: BACKGROUND AND AIM: To evaluate the benefits of contrast-enhanced ultrasound (CEUS) with high frequency transducers in characterization of focal gallbladder lesions (FGL). MATERIAL AND METHODS: From January 2017 to April 2019, 59 FGL detected by B mode ultrasound (BMUS) were examined, first with the low frequency convex transducer (1–5 MHz) and afterwards with high frequency transducer (7.5–12 MHz). High frequency dynamic CEUS were applied after bolus injection of 4.8 ml Sulphur hexafluoride microbubbles (SonoVue® , Milan). The BMUS and CEUS imaging features were recorded and compared. All lesions were confirmed by surgical resection and histopathologic results. RESULTS: The final …diagnoses of 59 FGL included gallbladder adenocarcinoma (n  = 15), gallbladder polyps (n  = 11), gallbladder adenomas (n  = 18), focal adenomyomatosis (n  = 9), and gallbladder Ascariasis debris (n  = 6). The mean diameter of FGL was 24.5±11.4 mm, and mean depth to the abdominal wall was 21.2±7.3 mm. While applying CEUS with high frequency transducer, specific diagnostic features, including arterial phase irregular intralesional vascularity (10/15, 66.7%), late phase hypoenhancement (12/15, 80%), destruction of gallbladder wall (8/15, 53.3%), infiltration to the adjacent liver (6/15, 40.0%) were significantly higher in malignant FGL. The overall sensitivity, specificity and diagnostic accuracy for the correct characterization of malignant FGL were significantly improved by CEUS with high frequency transducer (sensitivity 93.3%, specificity 88.5%, accuracy 100%). CONCLUSION: With its superior contrast resolution, CEUS performed with high frequency transducers is helpful to achieve better visualization of gallbladder fundus and make differential diagnosis of gallbladder lesions, which might greatly improve diagnostic confidence between malignant and benign FGL. Show more

Keywords: Contrast enhanced ultrasound (CEUS), focal gallbladder lesion, high frequency, diagnosis, differentiation

DOI: 10.3233/CH-190639

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 167-178, 2020

Authors: Xie, Juan | Liu, Hui | Liu, Wen-sheng | Li, Jia-wei

Article Type: Research Article

Abstract: PURPOSE: To evaluate the diagnostic value of quantitative shear wave elastography (SWE) for the differential diagnosis of solid pancreatic tumors. MATERIALS AND METHODS: A total of 66 solid pancreatic masses were enrolled in this study and all the lesions underwent quantitative SWE. The stiffness of the masses was expressed in shear wave velocity (SWV, m/s). The receiver operating characteristic (ROC) curve was plotted to assess the diagnostic performance of quantitative SWE. The optimal cutoff value for SWV in the differentiation of benign from malignant masses was determined. RESULTS: The final diagnoses were 26 benign and 40 …malignant masses. The SWVs were statistically higher for pancreatic malignant masses compared with those for benign masses (3.30±1.22 m/s versus 1.31±0.64 m/s; P  < 0.001). The area under the curve (AUC, 0.93) was obtained. When the best cut-off point was 1.77 m/s, the accuracy, sensitivity, and specificity were 92.4%, 90.0%, and 96.2%, respectively. CONCLUSIONS: Quantitative SWE is a novel technique that can be considered as a quantitative and objective diagnostic tool for prediction of pancreas malignancy. Show more

Keywords: Elasticity imaging techniques, pancreatic neoplasms, ultrasonography

DOI: 10.3233/CH-190665

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 179-187, 2020

Authors: Wang, Yali | Wu, Feng | Hu, Feng | Wu, Yunjiang | Zhou, Jun | Xu, Yan | Shao, Xiangrong | Hu, Tao

Article Type: Research Article

Abstract: Drag-reducing polymers (DRPs) was previously demonstrated to increase blood flow, tissue perfusion, and reduce vascular resistance. The purpose of this study was to investigate the effect of DRPs on pulmonary vascular remodeling and right ventricular dysfunction in a rat model of chronic hypoxia-induced pulmonary hypertension (HPH). A total of forty male Wistar rats were randomly and equally assigned into four experimental groups (Group I: normoxia + saline, Group II: normoxia + PEO, Group III: hypoxia + saline, Group IV: hypoxia + PEO) and maintained in normoxia (21% O2 ) or hypobaric hypoxia (10% O2 ). After four weeks, comparisons were …made of the following aspects: the mean pulmonary arterial pressure (mPAP), right ventricular systolic pressure (RVSP), right ventricular hypertrophy, wall thickness of pulmonary trunk and arteries, internal diameter of pulmonary arteries, cardiomyocyte cross-sectional area (CM CSA), and ultrastructure of right ventricular. Treatment with PEO in Group IV attenuated the increases in RVSP and mPAP (40.5±7.2 and 34.7±7.0 mmHg, respectively, both P  < 0.05), compared with Group III. Distal vascular remodeling was visible as a significant increase in medial wall thickness (64.2±12.3% vs. 43.95±7.0%, P  < 0.01) and a remarkable decrease in internal diameter of small pulmonary arteries (35.2±9.7μ m vs. 50.4±14.7μ m, P  < 0.01) in Group III, to a greater extent than that detected in Group IV. Nevertheless, no significant histopathological differences in medial wall thickness was observed in pulmonary trunk between Group III and Group IV (P  > 0.05), denoting that PEO chiefly attenuated the remodeling of small pulmonary arteries rather than main arteries in hypoxic environment. Infusion of DRPs (intravenous injection twice weekly) also attenuated the index of right ventricular hypertrophy, protected against the increase of cardiomyocyte cross-sectional area, and provided protection for cardiac ultrastructure. DRP treatment with intravenous injection elicited a protective effect against pulmonary vascular remodeling and right ventricular dysfunction in the rat model of HPH. DRPs may offer a new potential approach for the treatment of HPH, which may have theoretical significance and application value to society. Show more

Keywords: Drag-reducing polymers, vascular remodeling, right ventricular, chronic hypoxia, pulmonary hypertension

DOI: 10.3233/CH-190668

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 189-200, 2020

Authors: Raberin, Antoine | Nader, Elie | Ayerbe, Jorge Lopez | Mucci, Patrick | Connes, Philippe | Durand, Fabienne

Article Type: Research Article

Abstract: Blood rheology and hemodynamic parameters have never been explored together during acclimatization to altitude. This study aimed to investigate changes in blood rheology parameters and pulmonary hemodynamics during the first days of real moderate altitude exposure. Seventeen athletes were tested at sea-level, 20 hours after their arrival at 2,400 meters of altitude (H1) and five days later (H2). Blood was sampled to analyze red blood cell (RBC) aggregation, blood viscosity and hematocrit. Pulmonary arterial pressure (PAP), pulmonary capillary pressure (Pcap) and pulmonary vascular resistance (PVR) were assessed by echocardiography. We observed a rise in hematocrit, blood viscosity, RBC …aggregation, PAP, Pcap and PVR between sea-level and H1. In H2, RBC aggregation, hematocrit, PAP, Pcap and PVR remained different compared to sea-level and no difference was observed between H1 and H2. Blood viscosity decreased in H2 and returned to sea-level values. Our results suggest that hemoconcentration occurring within the first hours of altitude exposure increased blood viscosity, which contributed to the changes in pulmonary hemodynamic. When blood viscosity decreased in H2, no change occurred in pulmonary hemodynamic parameters suggesting that hypoxic pulmonary vasoconstriction was still present. The elevated RBC aggregation observed after in H2 could participate in the increase of Pcap. Show more

Keywords: Moderate altitude, pulmonary arterial pressure, pulmonary vascular resistance, blood viscosity, red blood cell aggregation

DOI: 10.3233/CH-190671

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 201-208, 2020

Authors: Sengoz, Tarik | Kilic-Toprak, Emine | Yaylali, Olga | Kilic-Erkek, Ozgen | Ozdemir, Yasin | Oymak, Burak | Senol, Hande | Yuksel, Dogangun | Kucukatay, Vural | Bor-Kucukatay, Melek

Article Type: Research Article

Abstract: BACKGROUND: Although radioiodine theraphy (RAIT) is thought to affect blood cells and oxidative stress, hemorheological alterations following dose-dependent RAIT remains unknown. OBJECTIVE: The aim of this study was to determine the effects of RAIT on hemorheological and oxidative stress parameters in patients with differentiated thyroid cancers (DTC). METHODS: Totally 31 DTC patients (mean age 46.32±11.15 years) and 26 healthy controls (mean age 50.50±6.22 years) were included. Venous blood samples were collected from each patient before and after treatment (7th day, 1th month and 6th month). Erythrocyte aggregation-deformability and oxidative stress parameters were determined. …p  < 0.05 was considered as statistically significant. RESULTS: Erythrocyte deformability of the patients determined at 16.87 and 30 Pascal were significantly lower than healthy individuals. Erythrocyte aggregation index (AI) of the patients was higher, whereas erythrocyte aggregation half-time (t½) was lower compared to control. Erythrocyte deformability values and AI were not significantly different from the pre- and post-radioiodine treatment groups. There was no statistically significant difference between the oxidative stress parameters before and after the treatment. CONCLUSIONS: Patients were in a worse hemorheological condition compared to healthy individuals. After RAIT, RBC deformability and aggregation were not affected and no significant change in oxidative stress parameters was detected. Show more

Keywords: Differentiated thyroid cancer, I-131, erythrocyte deformability, erythrocyte aggregation, oxidative stress

DOI: 10.3233/CH-190717

Citation: Clinical Hemorheology and Microcirculation, vol. 74, no. 2, pp. 209-221, 2020