Value of duplex doppler ultrasonography in non-invasive assessment of children with chronic liver disease

Comparison of portal vein hemodynamics with ultrasound-based elastography for the prediction of liver fibrosis in patients with chronic liver disease

Chronic liver disease includes nonalcoholic fatty liver disease, progresses from steatosis and hepatitis to fibrosis and cirrhosis, with hemodynamic changes in portal blood flow. This study aimed to compare portal vein hemodynamics with liver stiffness (LS) and steatosis and included 28 subjects with chronic liver disease, in whom LS and steatosis were evaluated in the same image employing two elastography techniques: transient elastography (TE) with controlled attenuation parameter (CAP) using a FibroScan and two-dimensional shear-wave elastography (2D-SWE) with attenuation imaging (ATI). Additionally, peak maximum velocity (V_max) of the right portal vein and spleen stiffness with 2D-SWE were evaluated. A strong positive correlation was present between LS values obtained with TE and 2D-SWE and between the attenuation coefficients of steatosis obtained with CAP and ATI. Additionally, a negative correlation was present between LS values and the V_max of the right portal vein (r = 0.415, p = 0.031). The optimal V_max cutoff value for discriminating liver fibrosis with an LS value of > 5 kPa was < 17 cm/s; the ability of V_max to predict fibrosis was comparable to that of the FIB4-index. Low V_max of the right portal vein was useful for identifying liver fibrosis in patients with chronic liver disease.

Identification of liver fibrosis using the hepatic vein waveform in patients with Fontan circulation

AIM

Liver fibrosis caused by congestive hepatopathy has emerged as an important complication after Fontan procedure. We evaluated the utility of the hepatic vein (HV) waveform using Doppler ultrasound for identification of liver fibrosis in Fontan patients.

METHODS

We investigated the HV waveforms in 41 Fontan patients and assessed correlations with clinical parameters, liver fibrosis markers, and hemodynamic data.

RESULTS

Based on our preliminary analysis of 64 adult patients with chronic liver disease who underwent liver biopsy, we classified HV waveforms into five types with reference to the degree of flattening (from type 1, normal triphasic waveform; to type 5, a monophasic waveform indicating cirrhosis), and confirmed a significant correlation between waveform pattern and fibrosis stage. Notably, we detected HV waveforms in all of the Fontan patients and classified them into five types. The HV waveform pattern positively correlated with γ-glutamyl transferase and hyaluronic acid levels, and negatively correlated with albumin level and platelet count, but did not correlate with central venous pressure or brain natriuretic peptide level, suggesting that HV waveform could reflect pathophysiological changes in the liver without being affected by hepatic congestion. The highest area under the receiver operating characteristic curve of the HV waveform for detecting advanced liver fibrosis, as defined by ultrasonic findings and clinical features, was 0.829 (81.8% sensitivity, 73.3% specificity), which was higher than that of other non-invasive fibrosis markers.

CONCLUSIONS

Hepatic vein waveforms change in accordance with liver fibrosis progression in Fontan patients, and can be a useful indicator of liver fibrosis after the Fontan procedure.

Doppler assessment of children with liver cirrhosis and portal hypertension in comparison with a healthy control group: An analytical cross-sectional study

Background:

Doppler ultrasonography (Doppler US) plays an important role in evaluating patients with liver cirrhosis. This study aims to investigate the hemodynamic alterations of hepatic artery and portal vein among children with liver cirrhosis and portal hypertension (esophageal varices).

Materials and Methods:

We conducted an analytical cross-sectional study in Imam Hossein Children's Hospital, Isfahan, Iran, in 2016. A number of 33 cirrhotic children with or without esophageal varices were selected through convenience sampling method to be compared with 19 healthy children as controls using color and spectral Doppler US.

Results:

Portal vein mean velocities were 15.03 ± 7.3 cm/s in cirrhotics, 16.47 ± 6.4 cm/s in controls (P = 0.51), 11.6 ± 4.7 cm/s in patients with varices, and 17.9 ± 7.3 cm/s in patients without varices (P = 0.015). Mean diameters of caudate lobe, portal vein, and splenic vein, as well as the mean values of liver and spleen span, were significantly higher in cirrhotic children. The frequency of flow reversal (hepatofugal flow) was not detected significantly different in cirrhotics. Peak systolic velocity, end diastolic velocity, pulsatility index, and resistive index for hepatic artery as well as liver vascular index were not significantly different in cirrhotics in comparison with controls.

Conclusion:

Alterations in Doppler parameters of portal vein including diameter and velocity may be the helpful indicators of liver cirrhosis and esophageal varices in children, respectively. Parameters of hepatic artery may not differentiate children with liver cirrhosis.

Liver and systemic hemodynamics in children with cirrhosis: Impact on the surgical management in pediatric living donor liver transplantation

Cirrhosis in adults is associated with modifications of systemic and liver hemodynamics, whereas little is known about the pediatric population. The aim of this work was to investigate whether alterations of hepatic and systemic hemodynamics were correlated with cirrhosis severity in children. The impact of hemodynamic findings on surgical management in pediatric living donor liver transplantation (LT) was evaluated. Liver and systemic hemodynamics were studied prospectively in 52 children (median age, 1 year; 33 with biliary atresia [BA]). The hemodynamics of native liver were studied preoperatively by Doppler ultrasound and intraoperatively using invasive flowmetry. Portosystemic gradient was invasively measured. Systemic hemodynamics were studied preoperatively by Doppler transthoracic echocardiography and intraoperatively by using transpulmonary thermodilution. Hemodynamic parameters were correlated with Pediatric End-Stage Liver Disease (PELD) score and the histological degree of fibrosis (collagen proportionate area [CPA]). Cirrhosis was associated with a 60% reduction of pretransplant total liver flow (n = 46; median, 36 mL/minute/100 g of liver) compared with noncirrhotic livers (n = 6; median, 86 mL/minute/100 g; P = 0.002). Total blood flow into the native liver was negatively correlated with PELD (P < 0.001) and liver CPA (P = 0.005). Median portosystemic gradient was 14.5 mm Hg in children with cirrhosis and positively correlated with PELD (P < 0.001). Portal vein (PV) hypoplasia was observed mainly in children with BA (P = 0.02). Systemic hemodynamics were not altered in our children with cirrhosis. Twenty-one children met the intraoperative criteria for PV reconstruction using a portoplasty technique during the LT procedure and had a smaller PV diameter at pretransplant Doppler ultrasound (median = 3.4 mm; P < 0.001). Cirrhosis in children appears also as a hemodynamic disease of the liver, correlated with cirrhosis severity. Surgical technique for PV reconstruction during LT was adapted accordingly. Liver Transplantation 23 1440-1450 2017 AASLD.

The effects of laser treatment in tendinopathy: a systematic review

Tendons have as main function transmit forces from the muscle to the bones. Tendinopathy is an inflammatory process that occurs in and around the tendon, when these are affected by some injury. Low level laser therapy consists in a local application of a monochromatic, coherent and short wavelength light. Its use began in 60's and since then several benefits for tendon injuries have been reported. The objective of this study is to collect the most recent studies about the use of laser on the tendinopathy treatment. We performed searches on the following electronic databases PubMed, Medline, CAPES journals portal and LILACS. After the analysis, we selected three articles that showed that the use of low-level laser therapy, compared to placebo, is effective in treatment of tendinopathy. Despite the need for more studies about this theme, the low-level laser therapy demonstrates consistent results in the treatment of tendinopathy.

Detection of hepatic hemodynamics in normal rhesus monkeys using high-frequency ultrasound

The rhesus monkey liver disease model provides useful information for hepatic research, as studies of hepatic hemodynamics in humans are rare. A 3-9 MHz high-frequency linear transducer (iU22, Philips Medical Systems, Royal Philips Electronics, The Netherlands) was used to obtain ultrasonograms of the livers of 28 normal rhesus monkeys (16 males, 12 females). Diameters of the portal vein and proper hepatic artery; maximum velocity of the portal vein; and peak-systolic and end-diastolic velocity and resistive index of the proper hepatic artery were also assessed. The portal vein and proper hepatic artery were 0.584 ± 0.123 and 0.151 ± 0.052 cm in diameter, respectively. The maximum velocity of the portal vein was 40.2 ± 13.7 cm/s. Peak systolic velocity and resistive index of the proper hepatic artery were 72.2 ± 25.4 cm/s and 0.67 ± 0.10, respectively. We found that high-frequency Doppler ultrasonography can be used to obtain clear portal vein and proper hepatic artery ultrasonograms and to measure the hemodynamic parameters of the portal vein and proper hepatic artery in rhesus monkeys. It is thus an effective method for studying changes in hepatic hemodynamics and has interesting technical and therapeutic implications. Our results provide useful information and establish normal reference values for future studies of adult healthy rhesus monkeys.

Update on a Pharmacokinetic-Centric Alternative Tier II Program for MMT-Part II: Physiologically Based Pharmacokinetic Modeling and Manganese Risk Assessment

Recently, a variety of physiologically based pharmacokinetic (PBPK) models have been developed for the essential element manganese. This paper reviews the development of PBPK models (e.g., adult, pregnant, lactating, and neonatal rats, nonhuman primates, and adult, pregnant, lactating, and neonatal humans) and relevant risk assessment applications. Each PBPK model incorporates critical features including dose-dependent saturable tissue capacities and asymmetrical diffusional flux of manganese into brain and other tissues. Varied influx and efflux diffusion rate and binding constants for different brain regions account for the differential increases in regional brain manganese concentrations observed experimentally. We also present novel PBPK simulations to predict manganese tissue concentrations in fetal, neonatal, pregnant, or aged individuals, as well as individuals with liver disease or chronic manganese inhalation. The results of these simulations could help guide risk assessors in the application of uncertainty factors as they establish exposure guidelines for the general public or workers.