Assessment Of Blood Flow Velocity Research Articles

Dynamics of rheological and biochemical blood parameters of patients with an intermediate stage of the dry form of age-related macular degeneration before and after serum cascade filtration

BACKGROUND: One of the socially significant ophthalmic diseases is the dry form of the age-related macular degeneration, the key feature of which consists in a slowly progressing damage to the pigment epithelium and the formation of drusen. However, the basic mechanisms of pathogenesis are still not completely clear nowadays. AIM: The aim is, using the data of OCT, OCT-angiography and visometry, to study the dynamics of structural and functional parameters of the macular area, as well as the dynamics of rheological and biochemical blood parameters in patients with an intermediate stage of the dry form of age-related macular degeneration before and after the use of serum cascade filtration. MATERIALS AND METHODS: The study included 63 patients (94 eyes) with an intermediate stage of the dry form of age-related macular degeneration. Patients were randomly separated into two groups. The first (main) group consisted of 34 patients (52 eyes), in whom serum cascade filtration was performed; the second group (control) group included 29 patients (42 eyes) who did not receive any specific treatment. In patients of the main group, before and after the serum cascade filtration course (1 month after the start of follow-up), in 6 and 12 months, in addition to standard ophthalmological examination, as an indicator of the efficacy of performed serum cascade filtration, the ultrasound triplex scanning in color Doppler mapping mode with an assessment of blood flow velocity in the posterior short ciliary arteries, Fourier IR spectroscopy, and the testing of the serum and blood viscosity were performed. Patients in the control group also underwent a similar examination at 1, 6, 12 months after the start of follow-up. RESULTS: According to optical coherence tomography, optical coherence tomography-angiography and visometry data, we found a positive dynamics of structural and functional parameters of the macular retina and an improvement in blood rheological parameters with an increase in microcirculation indices against the background of the serum cascade filtration use in treatment of patients with an intermediate stage of the dry form of age-related macular degeneration. At the same time, a statistically significant difference between the two groups begins at 1 month and persists for 12 months of follow-up, being an evidence of the stabilization of the pathological process. CONCLUSIONS: This study showed that after the serum cascade filtration in patients with an intermediate stage of the dry form of age-related macular degeneration, against the background of an improvement in blood rheological and biochemical parameters, there was an improvement in structural and functional parameters of the macular area, which consisted in a decrease of the volume of the drusenoid retinal pigment epithelium detachment and in a visual acuity amelioration.

Assessment of Blood Flow Velocity in Retinal Vasculitis Using the Retinal Function Imager-A Pilot Study.

Background: This pilot study aimed to evaluate the Retinal Function Imager (RFI) for visualizing retinal vasculature and assessment of blood flow characteristics in patients with retinal vasculitis. The RFI is a non-invasive imaging device measuring the blood flow velocity (BFV) in secondary and tertiary retinal vessels using hemoglobin as an intrinsic motion-contrast agent. Methods: To test the feasibility of the RFI for patients with retinal vasculitis, capillary perfusion maps (nCPMs) were generated from 15 eyes of eight patients (five females; mean age: 49 ± 12 years) with a mean uveitis duration of 74 ± 85 months. Five of these patients had birdshot chorioretinopathy, and three had primarily non-occlusive venous retinal vasculitis of unknown origin. To reflect that the BFV may be more reduced in patients with prolonged disease, patients were classified into a short-term (uveitis duration: 8-15 months) and a long-term uveitis group (uveitis duration: 60-264 months). Data were compared with healthy controls (16 eyes of 11 patients; mean age 45 ± 12 years; 8 females). Results: The mean BFV in the controls was 3.79 ± 0.50 mm/s in the retinal arteries and 2.35 ± 0.44 mm/s in the retinal veins, which was significantly higher compared to the retinal vasculitis group. Patients revealed an arterial BFV of 2.75 ± 0.74 mm/s (p < 0.001) and a venous BFV of 1.75 ± 0.51 mm/s (p = 0.016). In the short-term group, a trend towards a decreased venular and arteriolar BFV was seen, while a significant reduction was observed in the long-term group. The patients' microvasculature anatomy revealed by the nCPMs appeared unevenly distributed and a lower number of blood vessels were seen, along with a lower degree of complexity of their branching patterns, when compared with controls. Conclusions: This study demonstrated a reduction in venular and arteriolar BFVs in patients with retinal vasculitis. BFV alterations were already observed in early disease stages and became more pronounced in progressed disease. Additionally, we showed that retinal microvasculature changes may be observed by nCPMs. Retinal imaging with the RFI may serve as a diagnostic and quantifying tool in retinal vasculitis.

Diagnostic value of transcranial doppler to predict delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BackgroundTranscranial Doppler (TCD) is a technique to assess blood flow velocity in the cerebral arteries. TCD is frequently used to monitor aneurysmal subarachnoid hemorrhage (aSAH) patients. This study compares TCD-criteria for vasospasm and its association with Delayed Cerebral Ischemia (DCI). An overall score based on flow velocities of various intracranial arteries was developed and evaluated.MethodsA retrospective diagnostic accuracy study was conducted between 1998 and 2017 with 621 patients included. Mean flow velocity (MFV) of the cerebral artery was measured between 2–5 days and between 6–9 days after ictus. Cutoff values from the literature, new cutoff values, and a new composite score (Combined Severity Score) were used to predict DCI. Sensitivity, specificity, and area under the curve (AUC) were determined, and logistic regression analysis was performed.ResultsThe Combined Severity Score showed an AUC 0.64 (95%CI 0.56-.71) at days 2–5, with sensitivity 0.53 and specificity 0.74. The Combined Severity Score had an adjusted Odds Ratio of 3.41 (95CI 1.86–6.32) for DCI. MCA-measurements yielded the highest AUC to detect DCI at day 2–5: AUC 0.65 (95%CI 0.58–0.73). Optimal cutoff MFV of 83 cm/s for MCA resulted in sensitivity 0.73 and specificity 0.50 at days 2–5.ConclusionTCD-monitoring of aSAH patients may be a valuable strategy for DCI risk stratification. Lower cutoff values can be used in the early phase after the ictus (day 2–5) than are commonly used now. The Combined Severity Score incorporating all major cerebral arteries may provide a meaningful contribution to interpreting TCD measurements.

Abstract 222: Real Time Feedback of Chest Compressions by Hands-Free Carotid Doppler in a Porcine Model

Background: Real-time hemodynamic feedback devices provide information on cardiopulmonary resuscitation (CPR) quality. This can improve hand positioning and technique, thereby maximizing blood flow and potentially improve survival. Hypothesis: We hypothesize that a newly developed hands-free Doppler for carotid blood flow velocity (RescueDoppler, RD), can identify optimal vs. suboptimal chest compression sites during CPR. Aim: To assess the potential of the RD device to continuously monitor the effect of each compression by ultrasound metrics and waveforms in a porcine model. Methods: Ventricular fibrillation was induced in 5 pigs using an ICD. Manual CPR (blinded for hemodynamic data) was performed for 10 seconds at 3 different compression sites in random order (Fig.), and repeated 6 times. We analyzed ultrasound waveforms with Time Average Velocity (TAV) in a linear mixed model with site as fixed effect, and animal and site within animal as random effects. We further compared TAV to invasive systolic blood pressure (SBP) from the contralateral carotid artery. Results: Data from 5 pigs (mean weight 31.2 kg) and 29 of 30 sequences were included. Overall, blood flow velocity was highest at compression site 2 (TAV 33 cm/s, P&lt;0.01), but there was significant variability (P&lt;0.01) in animals (SD= 3.7) and at sites within animal (SD= 7). A compression site yielding the highest TAV (range 19 to 48 cm/s) or lowest TAV (6-25 cm/s) was successfully identified in all animals with corresponding SBPs 50-81 mmHg, and 46-64 mmHg, respectively. The correlation between TAV and SBP was 0.62-0.90 within animals. Conclusions In this animal study, a newly developed hands-free Doppler enabled assessment of blood flow velocity during CPR and detected significant variation according to chest compression site. RD identified the sites with both high and low blood flow velocities and is thus a promising device for effectively identifying the optimal and suboptimal chest compression sites during CPR.

Velocity vector comparison between vector flow imaging and computational fluid dynamics in the carotid bifurcation

It has been largely documented that local hemodynamic conditions, characterized by low and oscillating wall shear stresses, play a key role in the initiation and progression of vascular atherosclerotic lesions. Thus, investigation of the flow field in the carotid bifurcation can lead to early identification of vulnerable plaques. In this scenario, the development of novel non-invasive imaging tools that can be used in routine clinical practice to identify disturbed and recirculating blood flow becomes crucial. In this context, Vector Flow Imaging is becoming a relevant tool as it provides an angle independent assessment of blood flow velocity and multidimensional flow vector visualization. The purpose of the present study was to validate, in several locations of the carotid bifurcation, the high-frame rate vector flow imaging (HiFR-VFI) technique by comparing with computational fluid dynamic simulations (CFD).In all eight carotid bifurcations, HiFR-VFI accurately detected regions of laminar flow as well as recirculation and unsteady flow areas. An accurate and statistically significant agreement was observed between velocity vectors obtained by HiFR-VFI and those computed by CFD, both for vector magnitude (R = 0.85) and direction (R = 0.74).Our study demonstrated that HiFR-VFI is a valid technique for rapid and advanced visual representation of velocity field in large arteries. Thus, it has a great potential in research-based clinical practice for the identification of flow recirculation, low and oscillating velocity gradients near vessel wall. The use of HiFR-VFI may provide a great improvement in the investigation of the role of local hemodynamics in vascular pathologies, as well in the assessment of the effect of pharmacological treatments.

The Effect of 12-Week Treatment with Intermittent Negative Pressure on Blood Flow Velocity and Flowmotion, Measured with a Novel Doppler Device (Earlybird). Secondary Outcomes from a Randomized Sham-Controlled Trial in Patients with Peripheral Arterial Disease

Treatment with intermittent negative pressure (INP) is proposed as an adjunct to standard care in patients with peripheral arterial disease (PAD). The aims of this study were to evaluate the applicability of a novel ultrasound Dopplerdevice (earlybird) to assess blood flow characteristics in patients with PAD during a treatment session with INP, and whether certain flowproperties could determine who could benefit from INP treatment. Secondary outcomes of data from a randomized sham-controlled trial were explored. Patients were randomized to 12weeks of treatment with 40mm Hg or 10mm Hg INP, for one hour twice daily. Earlybird blood flow velocity recordings were made before and after the 12-week treatmentperiod and consists of a 5-min recording in rest, 3-min during INP treatment and 5-min recording after ended INP test-treatment. Mean blood flow velocity (vmean), relative changes in flow and frequency spectrum by Fourier-transform of the respective bandwidths of endothelial, sympathetic, and myogenic functions, were analyzed for the different series of blood flow measurements. In total, 62 patients were eligible for analysis, where 32 patients were treated with 40mm Hg INP. The acquired recordings were of good quality and were used for descriptive analyses of flow characteristics. An immediate increase in vmean during the negative pressure periods of the INP test-treatment was observed in the 40mm Hg INP treatment group at both pre- and post-test. There was a significant difference between the treatment groups, with a difference between the medians of 13.7 (P<0.001) at pre-test and 10.7 (P<0.001) at posttest. This finding was confirmed with spectrum analysis by Fourier-transform of the bandwidth corresponding to INP treatment. The change in amplitude corresponding to myogenic function after 12-weeks of treatment, was significantly different in favor of the 40mm Hg INP treatment group. We were not able to detect the specific flow characteristics indicating who would benefit INP-treatment. Earlybird is an applicable tool for assessing blood flow velocity in patients with PAD. Analysis of the flow velocity recordings shows that INP induces an immediate increase in blood flow velocities during INP. The positive effects of INP may be attributed to recruitment of arterioles, and thereby, increasing blood flow. In these analyses, no flow characteristics were determined which could predict who would benefit INP treatment.

Pulsatility Index in the Basal Ganglia Arteries Increases with Age in Elderly with and without Cerebral Small Vessel Disease.

Cerebral small vessel disease contributes to stroke and cognitive impairment and interacts with Alzheimer disease pathology. Because of the small dimensions of the affected vessels, in vivo characterization of blood flow properties is challenging but important to unravel the underlying mechanisms of the disease. A 2D phase-contrast sequence at 7T MR imaging was used to assess blood flow velocity and the pulsatility index of the perforating basal ganglia arteries. We included patients with cerebral amyloid angiopathy (n = 8; identified through the modified Boston criteria), hypertensive arteriopathy (n = 12; identified through the presence of strictly deep or mixed cerebral microbleeds), and age- and sex-matched controls (n = 28; no cerebral microbleeds). Older age was related to a greater pulsatility index, irrespective of cerebral small vessel disease. In hypertensive arteriopathy, there was an association between lower blood flow velocity of the basal ganglia and the presence of peri-basal ganglia WM hyperintensities. Our results suggest that age might be the driving factor for altered cerebral small vessel hemodynamics. Furthermore, this study puts cerebral small vessel disease downstream pathologies in the basal ganglia region in relation to blood flow characteristics of the basal ganglia microvasculature.

Physiological asymmetry in uterine artery blood flow during the first trimester of pregnancy: New insights from a quantitative assessment using Pulsed-wave color Doppler and M-mode color power angio imaging

IntroductionThis study aimed to quantify uterine artery (UtA) blood flow and its hemodynamic components throughout the first trimester of pregnancy using Doppler ultrasound. MethodsCross-sectional cohort study involving women undergoing a routine ultrasound scan between 5 and 13 weeks' gestation. UtA blood flow was measured using Pulsed-wave Color Doppler to assess blood flow velocity across the cardiac cycle and M-mode Color Power Angio imaging to assess UtA diameter. A formula was applied to calculate systolic and diastolic blood flow volumes according to Poiseuille's equation. ResultsA total of 330 women with a single viable first-trimester pregnancy agreed to participate in this study. A stepwise increase in total UtA blood flow was observed during the first trimester, with significant increases at 7, 8, and 11 weeks. No significant differences in blood flow were observed between right and left UtAs. However, there was a statistically significant difference when comparing the UtA based on higher and lower blood flow, with a mean ± SD of 64.4% ± 10.5% through the former (p < 0.001). The increase in the UtA blood flow was secondary to an increase in the blood flow rate between 5 and 10 weeks. A significant increase in UtA diameter was only identified from 11 weeks onwards. DiscussionUtA blood flow in the first trimester is asymmetrical, at a constant ratio of ≈2:1. An interpretive model of the possible origin of this pattern during early pregnancy is proposed.

Microvascular Imaging as a Novel Tool for the Assessment of Blood Flow Velocity in Patients with Systemic Sclerosis: A Single-Center Feasibility Study

Systemic sclerosis is an autoimmune disease characterized by organ fibrosis and vasculopathy. Almost all patients suffer from Raynaud’s phenomenon. Nailfold video capillaroscopy is the most widely imaging technique available, but flow quantification is impossible. Therefore, novel imaging techniques are of interest. We performed a single-center feasibility study using Microvascular Imaging (MVI) for flow quantification of small fingertip vessels. We compared 20 healthy controls (HCs) with 20 systemic sclerosis (SSc) patients. In HCs, measurements were, on average, statistically significantly higher when combined for all fingers (median 10.68 vs. 6 cm/s, Δ = 4.68 cm/s, p &lt; 0.0001) and for individual fingers. An optimal cut-off value of peak systolic (PS) velocity of &lt;6.13 cm/s and end-diastolic (ED) velocity of &lt;2.13 cm/s discriminated HCs from SSc. Test characteristics for PS showed excellent sensitivity (0.90, 95% CI 0.70–0.98) and specificity (0.85, 95% CI 0.64–0.95; LR + 6.0). For ED velocity, sensitivity was 0.85 (95% CI 0.64–0.95) and specificity was 0.80 (95% CI 0.58–0.92, LR + 4.25). Here, we present the first study on the use of MVI to assess blood flow in the fingertips with high sensitivity and specificity in SSc. Future studies are needed to investigate correlations with the risk of organ complications, such as digital ulcers or pulmonary arterial hypertension.

Association between Tomographic Characteristics of the Temporal Bone and Transtemporal Window Quality on Transcranial Color Doppler Ultrasound in Patients with Stroke or Transient Ischemic Attack

Transcranial color-coded Doppler (TCCD) is an ultrasonographic technique used to obtain and evaluate images of the cerebral parenchyma and to assess blood flow velocities of the intracranial vessels. One of the major limitations of TCCD is the failure to insonate through the transtemporal window, which occurs in about 5%–44% of patients. Temporal bone thickness has been strongly associated with transtemporal window failure (TWF). The aims of the study were to evaluate the association between TWF on TCCD and radiologic findings on computed tomography of the skull along with the demographic characteristics of patients with acute stroke or transient ischemic attack (TIA), and to propose a classification for transcranial window quality (TWQ) on B-mode scan of TCCD. A total of 187 consecutive patients with acute stroke or TIA were included. Among them, 21.9% had TWF and 34.8% had TWQ categorized as insufficient on B-mode scan of TCCD. On logistic regression, age (odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.03–1.12, p < 0.001), female sex (OR = 5.99, 95% CI: 2.09–17.16, p = 0.001), pneumatized temporal bone (OR = 7.90, 95% CI: 1.95–32.03, p = 0.004) and temporal bone thickness (OR = 3.04, 95% CI: 1.73–5.35, p < 0.001) were independent predictors of TWF, even after adjusting for confounders. These findings may help to select patients in whom echogenic contrast or even other imaging methods could be used to assess intracranial vessels.

Guidelines for ultrasound examination in ophthalmology. Part III: Color Doppler ultrasonography.

The aim of this article was to present the possibilities of use and application of color-coded Doppler ultrasonography in the diagnosis of various diseases of the eyeball and orbit which result from vascular disorders. Color-coded Doppler ultrasonography is recommended for the assessment of blood flow velocity in the retrobulbar arteries. That is why the article contains current recommendations for Doppler imaging in ophthalmology. The paper provides detailed recommendations for patient’s preparation for the examination, presents the scanning technique and safety of the examination, and lists ophthalmological diseases of vascular origin for which color-coded Doppler ultrasonography can be applied. Furthermore, the article also presents other techniques applied in clinical practice for the assessment of blood flow or imaging of vasculature of a given eyeball structure, inter alia: power Doppler ultrasonography, 3D and 4D ultrasonography, magnetic resonance angiography, spiral computer tomography, transcranial ultrasonography and modern microvascular imaging. The authors emphasize the usefulness of color-coded Doppler ultrasonography in the diagnosis of diseases which result from blood flow disorders within the eyeball, such as amaurosis fugax, ocular ischemic syndrome, insufficiency in vessels supplying the carotid and vertebral arteries, posterior ischemic optic neuropathy, glaucoma, age-related macular degeneration, vascular vision disorders, vascular malformations, such as arteriovenous fistula, orbital varices, systemic connective tissue diseases in retinopathy of prematurity, diabetes, thyroid disorders or strabismus. The application of color-coded Doppler ultrasonography is especially important in the assessment of the vasculature of intrabulbar tumorous lesions and in the differential diagnosis of intrabulbar tumors.

Clinical Usefulness of Transcranial Doppler as a Screening Tool for Early Cerebral Hypoxic Episodes in Patients with Moderate and Severe Traumatic Brain Injury.

Brain tissue oxygenation (PbtO2) in traumatic brain injury (TBI) is known to be dependent on cerebral blood flow (CBF) which remains difficult to assess during the very early phase of TBI management. This study evaluates if blood flow velocity measurement with 2D color-coded transcranial Doppler (TCD) can predict cerebral hypoxic episodes in moderate-to-severe TBI measured with a PbtO2 probe. This is a prospective observational study of serial TCD measurements to assess blood flow velocity and its association with PbtO2. Measurements were done bilaterally on the middle cerebral artery (MCA) early after the insertion of PbtO2 monitoring, daily for 5days and during dynamic challenge tests. Physiological parameters affecting PbtO2 and Doppler velocities were collected simultaneously (PaO2, PaCO2, hemoglobin [Hb] level, intracranial pressure, and cerebral perfusion pressure [CPP]). We enrolled 17 consecutive patients with a total of 85 TCD studies. Using 2D color-coded TCD, signal acquisition was successful in 96% of the cases. Twenty-nine (34%) TCD measures were performed during an episode of cerebral hypoxia (PbtO2 ≤ 20mmHg). For early episodes of cerebral hypoxia (occurring ≤ 24h from trauma), all Vmean < 40cm/s were associated with an ipsilateral PbtO2 ≤ 20mmHg (positive predictive value 100%). However,when considering all readings over the course of the study, however, we found no correlation between PbtO2 and MCA's mean blood flow velocity (Vmean). Vmean is also positively correlated with PaCO2, whereas PbtO2 is also correlated with PaO2, CPP, and Hb level. Early TCD measurements compatible with low CBF (mean velocity < 40cm/s) detect brain tissue hypoxia early after TBI (≤ 24h) and could potentially be used as a screening tool before invasive monitoring insertion to help minimize time-sensitive secondary injury. Various factors influence the relationship between Vmean and PbtO2, affecting interpretation of their interaction after 24h.

The Assessment of Blood Flow Velocities in Retinal Collaterals in Diabetic Retinopathy.

Diabetic retinopathy (DR) is a microvascular disease characterized by capillary dropout and resultant retinal ischemia which then leads to retinal vascular remodeling. Our goal was to assess blood flow velocities in retinal collateral vessels in healthy and diabetic subjects with various stages of DR. In our pilot study, we enrolled five eyes of five healthy subjects (H), five eyes of four subjects with diabetes and no retinopathy (DM), three eyes of three subjects with mild non-proliferative diabetic retinopathy (MDR), and five eyes of four subjects with proliferative diabetic retinopathy (PDR). Following routine ophthalmic examination, all subjects were imaged using a retinal function imager (RFI; Optical Imaging Inc., Rehovot, Israel). The built-in software of the RFI was used to identify and segment retinal collaterals with measurement of the blood flow velocities (BFV). One-way ANOVA was performed for BFV, followed by Newman-Keuls post hoc test. The level of significance was set at 5%. The total number of collateral segments involved in the study was 30, 31, 21, and 39 in the H, DM, MDR, and PDR groups, respectively. The BFVs in the collaterals were significantly lower in PDR (H: 1.86 ± 0.67, DM: 1.91 ± 0.71, MDR: 1.71 ± 0.53, PDR: 1.37 ± 0.58 mm/s). The PDR group showed a statistically significant difference in the comparisons to all groups (p = 0.012, p = 0.008, and p = 0.043 for the H, DM, and MDR groups, respectively), while no other comparisons between the groups were significant. We observed decreased BFV in retinal collaterals in PDR that may be due to the extensive capillary dropout and retinal ischemia. Further studies are needed for the noninvasive functional assessment of retinal microvascular changes in DR to better understand the underlying pathophysiology.

Hemodynamic changes in hepatic sinusoids of hepatic steatosis mice.

BACKGROUNDFatty liver (FL) is now a worldwide disease. For decades, researchers have been kept trying to elucidate the mechanism of FL at the molecular level, but rarely involve the study of morphology and medical physics. Traditionally, it was believed that hemodynamic changes occur only when fibrosis occurs, but it has been proved that these changes already show in steatosis stage, which may help to reveal the pathogenesis and its progress. Because the pseudolobules are not formed during the steatosis stage, this phenomenon may be caused by the compression of the liver microcirculation and changes in the hemodynamics.AIMTo understand the pathogenesis of hepatic steatosis and to study the hemodynamic changes associated with hepatic steatosis.METHODSEight-week-old male C57BL/6 mice were divided into three groups randomly (control group, 2-wk group, and 4-wk group), with 16 mice per group. A hepatic steatosis model was established by subcutaneous injection of carbon tetrachloride in mice. After establishing the model, liver tissue from mice was stained with hematoxylin and eosin (HE), and oil red O stains. Blood was collected from the angular vein, and hemorheological parameters were estimated. A two-photon fluorescence microscope was used to examine the flow properties of red blood cells in the hepatic sinusoids.RESULTSOil red O staining indicated lipid accumulation in the liver after CCl4 treatment. HE staining indicated narrowing of the hepatic sinusoidal vessels. No significant difference was observed between the 2-wk and 4-wk groups of mice on morphological examination. Hemorheological tests included whole blood viscosity (mPas, γ = 10 s-1/γ = 100 s-1) (8.83 ± 2.22/4.69 ± 1.16, 7.73 ± 2.46/4.22 ± 1.32, and 8.06 ± 2.88/4.22 ± 1.50), red blood cell volume (%) (51.00 ± 4.00, 42.00 ± 5.00, and 40.00 ± 3.00), the content of plasma fibrinase (g/L) (3.80 ± 0.50, 2.90 ± 0.80, and 2.30 ± 0.70), erythrocyte deformation index (%) (44.49 ± 5.81, 48.00 ± 15.29, and 44.36 ± 15.01), erythrocyte electrophoresis rate (mm/s per V/m) (0.55 ± 0.11, 0.50 ± 0.11, and 0.60 ± 0.20), revealing pathological changes in plasma components and red blood cells of hepatic steatosis. Assessment of blood flow velocity in the hepatic sinusoids with a laser Doppler flowmeter (mL/min per 100 g) (94.43 ± 14.64, 80.00 ± 12.12, and 67.26 ± 5.92) and two-photon laser scanning microscope (μm/s) (325.68 ± 112.66, 213.53 ± 65.33, and 173.26 ± 44.02) revealed that as the modeling time increased, the blood flow velocity in the hepatic sinusoids decreased gradually, and the diameter of the hepatic sinusoids became smaller (μm) (10.28 ± 1.40, 6.84 ± 0.93, and 5.82 ± 0.79).CONCLUSIONThe inner diameter of the hepatic sinusoids decreases along with the decrease in the blood flow velocity within the sinusoids and the changes in the systemic hemorheology.

Role of Transcranial Doppler Assessment of Cerebral Blood Flow in Neonatal Sepsis

Neonatal sepsis is one of the leading causes of morbidity and mortality among term and preterm infants worldwide.assessment of the changes in cerebral blood flow velocity [CBFV] in cases of the neonatal sepsis.This study including 100 infants. 60neonates are diagnosed with neonatal sepsis [Sepsis group].while the other 40 neonates with no signs of neonatal sepsis [Control group]. Trans-cranial Doppler [TCD] was carried out for assessment of blood flow velocity in the anterior [ACA] and middle cerebral arteries [MCA] Peak systolic velocity [PSV], end diastolic velocity [EDV], and resistive index [RI] were measured.RI and PI were significantly decreased, with mean RI 0.56in MCA & Median RI in ACA 0.59 & Median PI 0.98; 0.98 in MCA & ACA respectively in the case group, while with a mean RI 0.75 in MCA & Median RI 0.72 in ACA respectively & Median PI1.35; 1.27 in MCA & ACA respectively .Whereas the Peak systolic velocity was increased with a mean of 69.07 in MCA & Median of 66.4 in ACA respectively in case group & mean of 50.22; in MCA & Median of 44.0 in ACA in control group with p value <0.001 in MCA & ACA respectively. neonatal sepsis causes increase in Peak systolic velocity & decrease in the Resistive & Pulsatility index thus causing increase in the cerebral blood flow, which in turn showed increased incidence in Intraventricular hemorrhage .

The role of portal congestion index in prediction of esophageal varices in hepatitis C virus-infected patients

Objective To assess the role of portal congestion index (PCI) in prediction of esophageal varices (EV) in hepatitis C virus (HCV)-infected patients. Background Portal hypertension (PH) often develops in HCV-infected patients. EV rupture leads to variceal bleeding, the most lethal complication of cirrhosis. Duplex Doppler ultrasonography of portal vein is a noninvasive method to assess blood flow velocity and portal vein cross-sectional area as a parameter for PH. Patients and methods This study was conducted on 200 HCV-infected patients (116 with EV and 84 without EV). Patients were subjected to complete blood picture, liver and kidney functions, serum electrolytes, viral markers, abdominal ultrasonography, upper gastrointestinal tract endoscopy, and duplex Doppler evaluation of portal vein with calculation of PCI. Results There was a highly significant difference between HCV-infected patients with and without EV regarding PCI (P = 0.0001). At cutoff point of PCI 0.11, the sensitivity, specificity, and accuracy to predict EV were 93, 85.7, and 90%, respectively, with area under the curve 0.889. There was a statistically highly significant positive correlation between PCI and presence of fundal varices and PH gastropathy (P = 0.0001). There was a statistically significant positive correlation between PCI and grades of EV (P = 0.012). Conclusion PCI is useful as a noninvasive predictor of EV in HCV-infected patients.

Validation of new marker of fluid responsiveness based on Doppler assessment of blood flow velocity in superior vena cava in mechanically ventilated pigs

BackgroundWe studied a novel approach for the evaluation and management of volemia: minimally invasive monitoring of respiratory blood flow variations in the superior vena cava (SVC). We performed an experiment with 10 crossbred (Landrace × large white) female pigs (Sus scrofa domestica).MethodsHypovolemia was induced by bleeding from a femoral artery, in six stages. This was followed by blood return and then an infusion of 1000 ml saline, resulting in hypervolemia. Flow in the SVC was measured by Flowire (Volcano corp., USA), located in a distal channel of a triple-lumen central venous catheter. The key parameters measured were venous return variation index (VRV)—a new index for fluid responsiveness, calculated from the maximal and minimal velocity time intervals during controlled ventilation—and systolic peak velocity (defined as peak velocity of a systolic wave using the final end-expiratory beat). A Swan–Ganz catheter (Edwards Lifesciences, USA) was introduced into the pulmonary artery to measure pulmonary arterial pressure, pulmonary capillary wedge pressure, and continuous cardiac output measurements, using the Vigilance monitor (Edwards Lifesciences, USA).ResultsWe analyzed 44 VRV index measurements during defined hemodynamic status events. The curves of VRV indexes for volume responders and volume non-responders intersected at a VRV value of 27, with 10% false negativity and 2% false positivity. We compared the accuracy of VRV and pulse pressure variations (PPV) for separation of fluid responders and fluid non-responders using receiver operating characteristic (ROC) curves. VRV was better (AUCROC 0.96) than PPV (AUCROC 0.85) for identification of fluid responders. The VRV index exhibited the highest relative change during both hypovolemia and hypervolemia, compared to standard hemodynamic measurement.ConclusionsThe VRV index provides a real-time method for continuous assessment of fluid responsiveness. It combines the advantages of echocardiography-based methods with a direct and continuous assessment of right ventricular filling during mechanical ventilation.

Abstract 4096: Stage-defined, transgenic immunocompetent mouse model (ASV-B) to investigate new drugs for hepatocellular carcinoma

Abstract Background: Hepatocellular carcinoma (HCC) is a complex multistep malignancy in need of new therapeutic options often arising on underlying chronic liver disease. HCC animal models relevant to clinical situations are crucial to investigate new anticancer drugs, alone or in combination. Mice bearing xenografts and transgenic mice are the two main models used for preclinical drug development, but most of them fail to mimic the different step of HCC observed in patients. In this study, we aim to describe a stage-defined, transgenic immunocompetent HCC mouse model. Methods: ASV-B is a transgenic mouse model that spontaneously develops, upon SV40 T-Ag oncogene expression in hepatocytes, a reproducible stage-defined HCC. Hyperplasia at week(W)8 is followed by nodular stage at W12 (multiple well-delimited tumor nodules of about 1 mm, growing progressively up to 1 cm), then diffuse carcinoma stage at W16-20. HCC is restricted to male, backcrossed with C57BL/6J mice, the female littermates being used as controls. Results: Liver volume assessed by ultrasound at each step of carcinogenesis showed a 2.7-, 2.7-, 3.9-, and 5.8-fold increase (p&amp;lt;0.001) in transgenic mice compared to controls (CTRL) at W8, 12, 16, and 20, respectively. ASV-B model displays marked arterialization with intense arterial flow in liver tumor similar to human HCC. Sinusoids in tumor nodules are tortuous and dilated, surrounded by activated hepatic stellate cells (HSCs) expressing smooth muscle actin (SMA) while HSCs surrounding normal sinusoids only express desmin. In addition, ASV-B livers develop along carcinogenesis a mesenchymal phenotype (increased vimentin and decreased e-cadherin staining), mimicking certain clinical situations of acquired resistance to VEGFR inhibitors. Angiogenesis, monitored using Doppler assessing blood flow velocity (BFV) in the hepatic artery, is enhanced by 29%, 51% and 156% at W8, W12 and W16, respectively, in transgenic liver animals as compared to CTRL. Increased angiogenesis was confirmed by CD31 staining in tumor specimen showing increased number of vessels per field. ASV-B model has been used to investigate the toxicity and efficacy of new drugs (galunisertib, MET/AXL inhibitor), including antiangiogenic agents (sorafenib and ramucirumab) alone or in combination, and may be relevant to explore the effects of immunotherapy agents. At the conference, we will display further characterization of liver tumors regarding vascularization, and immune cells localization using IHC. Conclusion: ASV-B transgenic mouse model mimics several characteristics of human HCC developing on healthy liver including multinodular disease, vessel abnormalities, and dedifferentiation toward mesenchymal phenotype. Further steps will consist of characterizing the adjacent nontumor liver, and developing nonalcoolic steatohepatitis (NASH) on ASV-B model using specific diets. Citation Format: Annemilaï Tijeras-Raballand, Patricia Hainaud, Christian Hobeika, Clarisse Eveno, Marc Pocard, Philippe Bonnin, Valérie Paradis, Mohamed Bouattour, Eric Raymond, Armand de Gramont, Evelyne Dupuy, Sandrine Faivre. Stage-defined, transgenic immunocompetent mouse model (ASV-B) to investigate new drugs for hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4096.

Assessment of blood flow velocities and venous pressures using a dual-sensor guidewire in symptomatic dural sinus stenoses.

Lateral venous sinus stenoses have been associated with idiopathic intracranial hypertension and venous pulsatile tinnitus. Venous pressure measurement is traditionally performed to assess the indications for stenting in patients with idiopathic intracranial hypertension. However, its reliability has recently been questioned by many authors. The dual-sensor guidewire was first developed for advanced physiological assessment of fractional and coronary flow reserves in coronary artery stenoses. It allows measurement of both venous pressure and blood flow velocities. The authors used this device in 14 consecutively treated patients to explore for symptomatic lateral sinus stenosis. They found that venous blood flow was significantly accelerated inside the stenotic lesion. This acceleration, as well as the pulsatile tinnitus, resolved in all patients following stent placement. According to the authors' results, this guidewire can be helpful for establishing an indication for stenting in patients with pulsatile tinnitus and idiopathic intracranial hypertension.

Application of shortwave diathermy to lower limb increases arterial blood flow velocity and skin temperature in women: a randomized controlled trial

BackgroundShortwave diathermy (SWD) and microwave diathermy (MWD) are frequently used by physical therapists to treat musculoskeletal conditions. The therapeutic benefits are usually associated with an increase in tissue temperature; however, there is no consensus on the changes in blood flow. Objectives1) To evaluate the behavior of temperature and arterial blood flow after the application of SWD and MWD to the lower limb of healthy women aged 18–30 and 2) to assess whether changes in limb positioning can influence SWD response. MethodAmong the subjects analyzed, 40 women were eligible to participate in the trial and were randomly allocated to the SWD group or the MWD group. Each group received 20min of diathermy. After receiving the interventions, all patients crossed over to the other group, but the devices were detuned (sham). SWD was applied to the posterior compartment of the thigh and leg, with the knee in 0° and 90° of flexion, and the MWD applied to the posterior thigh. Skin temperature evaluation (digital infrared thermography) and assessment of blood flow velocity (Doppler ultrasound) were performed immediately before and 10 and 20min after the application. ResultsArterial blood flow increased after SWD diathermy (vs. Sham), but not after MWD diathermy. SWD promoted skin heating at the end of therapy in all areas analyzed, remaining above baseline even 20min after the end of the application. MWD diathermy promoted skin heating in the posterior thigh, reflecting a rise in the temperature of the popliteal fossa area that remained for 10min after the end of the application. ConclusionThe increase in arterial blood flow velocity depends on the size of the heating area, since it was only observed in the application of the SWD. However, after 20min of application, the position of the lower leg did not affect the heating.