Transient elastography and sonography for prediction of liver fibrosis in infants with biliary atresia

Novel Scoring Systems and Age-Based Hepatic Shear Wave Stiffness Cut-Offs for Improving Sonographic Diagnosis of Biliary Atresia

OBJECTIVES

To make sonographic evaluation for biliary atresia (BA) more objective and reproducible using scoring systems, and evaluate hepatic shear wave elastography (SWE) as an adjunct in sonographic diagnosis of BA.

METHODS

Sixty-four infants with cholestatic jaundice were enrolled between June 2016 and March 2018 in this prospective observational cohort study. Sonography and SWE was performed with SuperSonic Aixplorer system. Novel scoring systems were developed incorporating established sonographic parameters and hepatic stiffness values and analysed using SPSS software.

RESULTS

Of the 18 patients confirmed as BA, 3 were misdiagnosed on conventional sonography (16.7%) as non-BA. Gall bladder (GB) wall irregularity and fasting GB length were the most accurate (93.8%) and most specific (97.8%) individual parameters, respectively. A significant difference was noted in the triangular cord (TC) thickness of BA and non-BA infants (p <0.001), with a high specificity of 95.6% for a 4 mm cut-off value for a positive TC sign. Comparison of hepatic SWE stiffness among age-matched groups of BA and non-BA showed significant differences (≤60 d: p = 0.003; >60 d: p <0.001) but with a reduced accuracy (93.8%). Diagnostic accuracy of greyscale scoring system (96.9%), greyscale + elastography scoring system in ≤60 d (94.4%) and >60 d (97.8%) were better than that of conventional sonographic diagnosis (93.8%).

CONCLUSIONS

Grey scale scoring system improves the accuracy of sonographic diagnosis of BA without any additional cost or time penalty along with making it universally reproducible. SWE has only an adjunctive role, if any, in the sonographic diagnosis of BA.

Preoperative imaging findings to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia

OBJECTIVES

To investigate the feasibility of using preoperative imaging indices to predict 2-year native liver survival after the Kasai procedure in patients with biliary atresia (BA).

MATERIALS AND METHODS

The retrospective review included 190 BA patients who underwent the Kasai procedure between 2000 and 2020, with preoperative US and/or MRI, excluding cases with less than 2-year follow-up period. Multivariable logistic regression analysis was performed to identify imaging indices to predict 2-year native liver survival. Kasai failure was defined as the need for liver transplantation or death within 2 years of the Kasai procedure.

RESULTS

Of the 90 patients included, all had preoperative US, and 61 also had MRI. Kasai failure occurred in 52% (47/90). Preoperative US identified gallbladder length (OR 0.40, 95% CI 0.17-0.95, p = 0.039; cutoff 1.6 cm, AUC 67.66) and biliary cysts (OR 24.64, 95% CI 1.97-308.08, p = 0.013) as significant Kasai failure predictors, with a combined accuracy of 73% (60/82). For patients having both preoperative US and MRI, significant predictors were hepatic artery diameter (OR 6.75, 95% CI 1.31-34.88, p = 0.023; cutoff 2 mm, AUC 73.83) and biliary cysts (OR 23.89, 95% CI 1.43-398.82, p = 0.027) on US, and gallbladder length (OR 0.25, 95% CI 0.08-0.76, p = 0.014; cutoff 1.2 cm, AUC 74.72) and spleen size (OR 2.53, 95% CI 1.02-6.29, p = 0.045; cutoff 6.9 cm, AUC 73.72) on MRI, with a combined accuracy of 85% (52/61).

CONCLUSION

Preoperative US and/or MRI enhance the 2-year native liver survival prediction in BA patients after the Kasai procedure.

CLINICAL RELEVANCE STATEMENT

BA patients with hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and absence of biliary cysts (US/MRI) have a decreased likelihood of 2-year native liver survival.

KEY POINTS

• Preoperative US and/or MRI can predict the probability of achieving 2-year native liver survival following the Kasai procedure. • Combining US and MRI improved the accuracy to 85% for predicting 2-year native liver survival in BA patients. • The hepatic artery diameter > 2 mm (US), gallbladder length < 1.6 cm (US) or < 1.2 cm (MRI), spleen size > 6.9 cm (MRI), and no biliary cysts (US/MRI) are significant predictors of Kasai failure in patients with biliary atresia.

Liver fibrosis in children: a comprehensive review of mechanisms, diagnosis, and therapy

Chronic liver disease incidence is increasing among children worldwide due to a multitude of epidemiological changes. Most of these chronic insults to the pediatric liver progress to fibrosis and cirrhosis to different degrees. Liver and immune physiology differs significantly in children from adults. Because most of pediatric liver diseases have no definitive therapy, a better understanding of population and disease-specific fibrogenesis is mandatory. Furthermore, fibrosis development has prognostic significance and often guide treatment. Evaluation of liver fibrosis continues to rely on the gold-standard liver biopsy. However, many high-quality studies put forward the high diagnostic accuracy of numerous diagnostic modalities in this setting. Herein, we summarize and discuss the recent literature on fibrogenesis with an emphasis on pediatric physiology along with a detailed outline of disease-specific signatures, noninvasive diagnostic modalities, and the potential for antifibrotic therapies.

Metabolic-Associated Fatty Liver Disease in Childhood and Adolescence

Metabolic-associated fatty liver disease (MAFLD) has become the most common cause for chronic liver disease among children and adolescents globally. Although liver biopsy remains the gold standard for diagnosis, emerging technology, like velocity controlled transient elastography, a noninvasive method, is being utilized to evaluate degree of fibrosis in these patients. The discovery of multiple gene polymorphisms has brought new hope for possible treatment targets. However, this research is still ongoing, making lifestyle changes and weight reduction the current mainstay of treatment. This review briefly reviews the most recent data regarding the epidemiology, pathophysiology, diagnostic modalities, and treatment of pediatric MAFLD.

Serum biomarkers correlated with liver stiffness assessed in a multicenter study of pediatric cholestatic liver disease

BACKGROUND AND AIMS

Detailed investigation of the biological pathways leading to hepatic fibrosis and identification of liver fibrosis biomarkers may facilitate early interventions for pediatric cholestasis.

APPROACH AND RESULTS

A targeted enzyme-linked immunosorbent assay-based panel of nine biomarkers (lysyl oxidase, tissue inhibitor matrix metalloproteinase (MMP) 1, connective tissue growth factor [CTGF], IL-8, endoglin, periostin, Mac-2-binding protein, MMP-3, and MMP-7) was examined in children with biliary atresia (BA; n = 187), alpha-1 antitrypsin deficiency (A1AT; n = 78), and Alagille syndrome (ALGS; n = 65) and correlated with liver stiffness (LSM) and biochemical measures of liver disease. Median age and LSM were 9 years and 9.5 kPa. After adjusting for covariates, there were positive correlations among LSM and endoglin ( p = 0.04) and IL-8 ( p < 0.001) and MMP-7 ( p < 0.001) in participants with BA. The best prediction model for LSM in BA using clinical and lab measurements had an R2 = 0.437; adding IL-8 and MMP-7 improved R2 to 0.523 and 0.526 (both p < 0.0001). In participants with A1AT, CTGF and LSM were negatively correlated ( p = 0.004); adding CTGF to an LSM prediction model improved R2 from 0.524 to 0.577 ( p = 0.0033). Biomarkers did not correlate with LSM in ALGS. A significant number of biomarker/lab correlations were found in participants with BA but not those with A1AT or ALGS.

CONCLUSIONS

Endoglin, IL-8, and MMP-7 significantly correlate with increased LSM in children with BA, whereas CTGF inversely correlates with LSM in participants with A1AT; these biomarkers appear to enhance prediction of LSM beyond clinical tests. Future disease-specific investigations of change in these biomarkers over time and as predictors of clinical outcomes will be important.

Noninvasive Prediction of Advanced Fibrosis in Pediatric Liver Disease-Discriminatory Performance of 2D Shear Wave Elastography, Transient Elastography and Magnetic Resonance Elastography in Comparison to Histopathology

Background: Elastography can be measured with different imaging techniques and is increasingly used for noninvasive assessment of hepatic fibrosis. Little is known about the performance, and interrelation of different elastographic techniques, in prediction of hepatic fibrosis in pediatric liver disease. Objectives: We aimed to determine the discriminatory value for advanced fibrosis (Metavir F3-4) and evaluate the applicability of 2D shear wave ultrasound elastography (USe), Transient Elastography (TE) and Magnetic Resonance elastography (MRe) in pediatric liver disease. Methods: In patients with pediatric liver disease aged 0−19 years, USe, TE and MRe were compared with histopathological fibrosis stage. Multivariate logistic regression models for advanced fibrosis were considered. Discriminative performance was assessed by the area under the receiver operating characteristic curve and the Brier Score. Primary analyses included complete cases. Multiple imputation was used as sensitivity analysis. Results: In 93 histologically evaluated patients USe, TE and MRe were performed 89, 93 and 61 times respectively. With increased liver stiffness values, significantly increased odds for presenting F3-4 were seen in individual models for ALT < 470 U/L, whereas the effect for ALT > 470 U/L was non-significant. Area under the curve and Brier Score for discrimination of advanced fibrosis were 0.798 (0.661−0.935) and 0.115 (0.064−0.166); 0.862 (0.758−0.966) and 0.118 (0.065−0.171); 0.896 (0.798−0.994) and 0.098 (0.049−0.148) for USe, TE and MRe respectively. No significant increase in discriminatory ability was found when combining elastographic modalities. Conclusions: In pediatric liver disease, USe, TE and MRe had a good discriminatory ability for assessment of advanced liver fibrosis, although TE and MRe performed best. In most children with pediatric liver disease, TE is a reliable and easily applicable measure.

Consensus on the management of complications of cirrhosis of the liver in pediatrics

The Asociación Mexicana de Hepatología A.C. carried out the Consensus on the Management of Complications of Cirrhosis of the Liver in Pediatrics to provide physicians with useful information for treating said complications. A group of pediatric gastroenterologists and experts in nutrition, nephrology, and infectious diseases participated and reviewed the medical literature. The Delphi method was applied to obtain the level of agreement on the statements that were formulated. The statements were sent to the participants to be analyzed and voted upon, after which they were discussed in virtual sessions, and the final versions were produced. The aim of the consensus results was to issue indications for the management of pediatric patients with liver cirrhosis, to prevent or control complications.

Use of shear wave elastography for the diagnosis and follow-up of biliary atresia: A meta-analysis

BACKGROUND

Timely differentiation of biliary atresia (BA) from other infantile cholestatic diseases can impact patient outcomes. Additionally, non-invasive staging of fibrosis after Kasai hepatoportoenterostomy has not been widely standardized. Shear wave elastography is an ultrasound modality that detects changes in tissue stiffness. The authors propose that the utility of elastography in BA can be elucidated through meta-analysis of existing studies.

AIM

To assess the utility of elastography in: (1) BA diagnosis, and (2) post-Kasai fibrosis surveillance.

METHODS

A literature search identified articles that evaluated elastography for BA diagnosis and for post-Kasai follow-up. Twenty studies met criteria for meta-analysis: Eleven for diagnosis and nine for follow-up post-Kasai. Estimated diagnostic odds ratio (DOR), sensitivity, and specificity of elastography were calculated through a random-effects model using Meta-DiSc software.

RESULTS

Mean liver stiffness in BA infants at diagnosis was significantly higher than in non-BA, with overall DOR 24.61, sensitivity 83%, and specificity 79%. Post-Kasai, mean liver stiffness was significantly higher in BA patients with varices than in patients without, with DOR 16.36, sensitivity 85%, and specificity 76%. Elastography differentiated stage F4 fibrosis from F0-F3 with DOR of 70.03, sensitivity 96%, and specificity 89%. Elastography also differentiated F3-F4 fibrosis from F0-F2 with DOR of 24.68, sensitivity 85%, and specificity 81%.

CONCLUSION

Elastography has potential as a non-invasive modality for BA diagnosis and surveillance post-Kasai. This paper’s limitations include inter-study method heterogeneity and small sample sizes. Future, standardized, multi-center studies are recommended.

Ultrasound elastography in the diagnosis of biliary atresia in pediatric surgery: a systematic review and meta-analysis of diagnostic test

BACKGROUND

Biliary atresia (BA) is one of the most fatal hepatobiliary diseases in infants and young children, and is easy to cause obstructive jaundice in infants and children, and liver transplantation in children. BA and infantile hepatitis syndrome are the main causes of cholestatic jaundice. The early clinical manifestations are extremely similar, and timely identification is difficult. Therefore, early and differential diagnosis of BA is crucial. At present, there are many imaging diagnosis methods for BA, such as ultrasound examination and nuclear magnetic resonance. Ultrasound elastography (USE) is the most popular method. However, the application of USE in BA is still in the exploratory stage.

METHODS

PubMed, Web of Science, Embase, Cochrane Library, and other databases were searched for articles on USE diagnosis of pediatric surgical BA. Later, the articles were screened, and the included articles should meet the following requirements: the research objects were children with BA; the intervention measures were USE diagnosis; the control group was diagnosed by other methods than USE. RevMan5.3 was adopted for quality assessment, and forest maps and summary receiver operating characteristic (SROC) curves were constructed.

RESULTS

Finally, seven articles covering 490 patients were included. There were 120 patients in the control group. The included articles showed good quality and there was no obvious bias. The area under the SROC curve (AUC) for USE diagnosis of BA was 0.93, the sensitivity was 0.93 (95% CI: 0.72-1.00), and the specificity was 0.95 (95% CI: 0.74-1.00).

DISCUSSION

USE showed high diagnostic value for pediatric surgical biliary tract closure.

Percutaneous ultrasound-guided cholecystocholangiography with microbubbles combined with liver biopsy for the assessment of suspected biliary atresia

BACKGROUND

Percutaneous ultrasound (US)-guided cholecystocholangiography is effective in diagnosing biliary atresia for infants with a gallbladder >1.5 cm in length on US. However, whether it is still effective for other types of gallbladders needs further clarification.

OBJECTIVE

To evaluate the diagnostic performance and safety of percutaneous US-guided cholecystocholangiography combined with liver biopsy in children with suspected biliary atresia and with different types of gallbladders on US.

MATERIALS AND METHODS

Sixty-five infants were referred for percutaneous US-guided cholecystocholangiography with microbubbles and liver biopsy after an equivocal (n=39) or highly suspected (n=26) US diagnosis of biliary atresia. Two radiologists evaluated US and percutaneous US-guided cholecystocholangiography images in consensus. One pathologist independently evaluated liver specimens. We used the unpaired t-test, Mann-Whitney U test and chi-square test to analyze the data.

RESULTS

Of the 65 infants, 59 (90.8%) underwent a successful percutaneous US-guided cholecystocholangiography, with both sensitivity and specificity of 100%. All six infants for whom puncture failed had contracted gallbladders. The sensitivity and specificity of liver biopsy in the diagnosis of biliary atresia were 89.7% (26/29) and 83.3% (30/36), respectively. When percutaneous US-guided cholecystocholangiography and liver biopsy were combined, all infants gained correct diagnosis, and in 35 infants (97.2%, 35/36) biliary atresia could be excluded without intraoperative cholangiography. Twenty-two of 65 infants (33.8%) had fluid collections around the liver related to puncture. None of these complications needed treatment.

CONCLUSION

Percutaneous US-guided cholecystocholangiography combined with liver biopsy appears safe and effective for excluding or confirming biliary atresia in cholestatic infants with a dilated gallbladder on US.

Sound touch elastography for assessing cirrhosis preoperatively in infants with biliary atresia: Comparison with serum fibrosis biomarkers

INTRODUCTION

The accurate assessment of the stages of hepatic fibrosis in children with biliary atresia (BA) before performing Kasai portoenterostomy (KPE) is of utmost importance. Some studies demonstrated that ultrasound elastography can be used to assess the stages of hepatic fibrosis by detecting liver stiffness. Therefore, the aim of this work was to explore the usefulness of sound touch elastography (STE) for preoperatively assessing liver cirrhosis in infants with BA.

METHODS

A total of 189 children from the Hunan Children's Hospital with highly suspected BA were selected for this study, and their preoperative liver STE values and related clinical data were collected. The pathological results of the liver stages were considered as the gold standard. Spearman correlation was used to analyze the correlation between each parameter and the stage of hepatic fibrosis, and the receiver operator characteristic (ROC) curve was used to analyze the diagnostic performance for cirrhosis of each parameter.

RESULTS

Among the selected 189 patients with suspected BA, 159 were included in this study and were composed of 3 at hepatic fibrosis stage F1, 45 at stage F2, 41 at stage F3, and 70 at stage F4, while no patients at stage F0 were present. Spearman correlation analysis showed that the liver STE value had the highest correlation with the stage of hepatic fibrosis, with a correlation coefficient of 0.813 (P < 0.001). The liver STE value had the highest diagnostic performance for hepatic cirrhosis compared to other biomarkers of serum fibrosis; the area under the ROC curve was 0.899 when the best cut-off value was 14.57 kPa. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 78.6, 84.3, 79.7, 83.3, and 81.8%, respectively.

CONCLUSION

The liver STE value has a high correlation with the stage of hepatic fibrosis in children with BA. STE has a good diagnostic performance in evaluating cirrhosis before KPE in children with BA.

What is the impact of methotrexate on liver in patients with juvenile idiopathic arthritis? Results of liver SWE performed in a single centre

OBJECTIVES

Long-term therapy with low-dose methotrexate (MTX) is widely used in treatment of rheumatic diseases, in children. The purpose of this study was to evaluate liver elasticity in patients with juvenile idiopathic arthritis (JIA) who received MTX and compare the results with control group.

METHODS

Liver elasticity was evaluated with shear wave elastography (SWE) technique in 25 patients aged 3-17 years who were followed up with JIA and received MTX and compared with 25 healthy controls of the same age and weight. Factors that had an effect on liver elasticity were examined.

RESULTS

The mean SWE value of patients was 2.64 ± 2.13 m/s and 24.10 ± 18.50 kPa, whereas 1.83 ± 0.16 m/s and 10.09 ± 1.83 kPa in control group. There was a significant difference in liver elasticity in the patient and control groups. When the patients were evaluated as Group 1 (< 1000 mg) and Group 2 (≥ 1000 mg) according to the cumulative MTX dose, no significant difference was obtained. There was positive correlation between liver elasticity and weekly MTX dose and age.

CONCLUSIONS

Our study revealed that liver elasticity significantly decreased in patients who received MTX when compared with the control group. The elastography technique will be understood better over time and used safely in many areas.

Ultrasound shear wave elastography: does it add value to gray-scale ultrasound imaging in differentiating biliary atresia from other causes of neonatal jaundice?

BACKGROUND

Neonatal/infantile jaundice is relatively common, and most cases resolve spontaneously. However, in the setting of unresolved neonatal cholestasis, a prompt and accurate assessment for biliary atresia is vital to prevent poor outcomes.

OBJECTIVE

To determine whether shear wave elastography (SWE) alone or combined with gray-scale imaging improves the diagnostic performance of US in discriminating biliary atresia from other causes of neonatal jaundice over that of gray-scale imaging alone.

MATERIALS AND METHODS

Infants referred for cholestatic jaundice were assessed with SWE and gray-scale US. On gray-scale US, two radiology readers assessed liver heterogeneity, presence of the triangular cord sign, hepatic artery size, presence/absence of common bile duct and gallbladder, and gallbladder shape; associated interobserver correlation coefficients (ICC) were calculated. SWE speeds were performed on a Siemens S3000 using 6C2 and 9 L4 transducers with both point and two-dimensional (2-D) SWE US. Both univariable and multivariable analyses were performed, as were receiver operating characteristic curves (ROC) and statistical significance tests (chi-squared, analysis of variance, t-test and Wilcoxon rank sum) when appropriate.

RESULTS

There were 212 infants with biliary atresia and 106 without biliary atresia. The median shear wave speed (SWS) for biliary atresia cases was significantly higher (P<0.001) than for non-biliary-atresia cases for all acquisition modes. For reference, the median L9 point SWS was 2.1 m/s (interquartile range [IQR] 1.7-2.4 m/s) in infants with biliary atresia and 1.5 m/s (IQR 1.3-1.9 m/s) in infants without biliary atresia (P<0.001). All gray-scale US findings were significantly different between biliary-atresia and non-biliary-atresia cohorts (P<0.001), intraclass correlation coefficient (ICC) range 0.7-1.0. Triangular cord sign was most predictive of biliary atresia independent of other gray-scale findings or SWS - 96% specific and 88% sensitive. Multistep univariable/multivariable analysis of both gray-scale findings and SWE resulted in three groups being predictive of biliary atresia likelihood. Abnormal common bile duct/gallbladder and enlarged hepatic artery were highly predictive of biliary atresia independent of SWS (100% for girls and 95-100% for boys). Presence of both the common bile duct and the gallbladder along with a normal hepatic artery usually excluded biliary atresia independent of SWS. Other gray-scale combinations were equivocal, and including SWE improved discrimination between biliary-atresia and non-biliary-atresia cases.

CONCLUSION

Shear wave elastography independent of gray-scale US significantly differentiated biliary-atresia from non-biliary-atresia cases. However, gray-scale findings were more predictive of biliary atresia than elastography. SWE was useful for differentiating biliary-atresia from non-biliary-atresia cases in the setting of equivocal gray-scale findings.

The Prognosis of Type III Biliary Atresia with Hilar Cyst

OBJECTIVE

To compare the outcome of biliary atresia (BA) patients with and without hilar cyst on preoperative ultrasound.

METHODS

A single center retrospective review of patients of BA with (n = 27) and without hilar cyst (n = 27) over a 5 y period was done. The patients were analyzed using propensity score matching to reduce selection bias. All patients were diagnosed as type III BA by histologic examination and cholangiograms. Clinicopathological characteristics and survival outcomes were compared between the two groups.

RESULTS

There were no significant intergroup differences between baseline characteristics and outcomes after Kasai portoenterostomy surgery in two groups. BA with hilar cyst group showed comparable survival outcomes to the BA without cyst group (cumulative 1-y, 2-y and 5-y overall survival rates with native liver 61.4% vs. 65.8%, P = 0.041; 45.0% vs. 49.0%, P = 0.57; 45.0% vs. 49.0%, P = 0.57). And the Kaplan-Meier survival curves showed no significant difference in cumulative survival with native liver between the two groups (P = 0.58).

CONCLUSIONS

Type III BA with hilar cyst had no better prognosis compared with Type III BA without cyst.

Transient elastography correlated to four different histological fibrosis scores in children with liver disease

Currently, liver histology is the gold standard for the detection of liver fibrosis. In recent years, new methods such as transient elastography (TE) have been introduced into clinical practice, which allow a non-invasive assessment of liver fibrosis. The aim of the present study was to investigate the predictive value of TE for higher grade fibrosis and whether there is any relevance which histologic score is used for matching. For this purpose, we compared TE with 4 different histologic scores in pediatric patients with hepatopathies. Furthermore, we also determined the aspartate aminotransferase-to-platelet ratio (APRI) score, another non-invasive method, to investigate whether it is equally informative. Therefore, liver fibrosis in 75 children was evaluated by liver biopsy, TE and laboratory values. Liver biopsies were evaluated using four common histological scoring systems (Desmet, Metavir, Ishak and Chevalier's semi-quantitative scoring system). The median age of the patients was 12.3 years. TE showed a good correlation to the degree of fibrosis severity independent of the histological scoring system used. The accuracy of the TE to distinguish between no/minimal fibrosis and severe fibrosis/cirrhosis was good (p = 0.001, AUC-ROCs > 0.81). The optimal cut-off value for the prediction of severe fibrosis was 10.6 kPa. In contrast, the APRI score in our collective showed no correlation to fibrosis.Conclusion: TE shows a good correlation to the histological findings in children with hepatopathy, independent of the used histological scoring system. What is Known: • The current gold standard for detecting liver fibrosis is liver biopsy. Novel non-invasive ultrasound-based methods are introduced to clinical diagnostics. • Most histological scores have been developed and evaluated in adult populations and for only one specific liver disease. What is New: • Transient elastography (TE) in children showed a good correlation to fibrosis severity irrespective of the utilized histological scoring system. • The aspartate aminotransferase-to-platelet ratio (APRI) showed no correlation with different stages of liver fibrosis in children.

Periportal thickening on magnetic resonance imaging for hepatic fibrosis in infantile cholestasis

BACKGROUND

Untreated neonatal cholestasis can progress to liver cirrhosis and end stage liver disease in infancy due to prolonged hepatocyte and biliary tree injury and may require liver transplantation. Therefore, non-invasive evaluation of hepatic fibrosis is important in infants with cholestasis.

AIM

To investigate the usefulness of periportal thickening (PT) measured on liver magnetic resonance imaging (MRI) for the assessment of hepatic fibrosis in infants with cholestasis including biliary atresia (BA).

METHODS

This retrospective study included infants less than 6 mo who underwent liver MRI and biopsy for the evaluation of infantile cholestasis. PT and spleen size were measured on MRI. Serologic assessment was based on aspartate transaminase to platelet ratio index (APRI). The grade of histopathologic fibrosis was assessed by the METAVIR grading system. Correlation and diagnostic performance of PT, normalized spleen size ratio (SR, using the upper normal size limit), and APRI for diagnosing hepatic fibrosis were obtained by receiver-operating characteristic (ROC) curve analysis.

RESULTS

A total of 155 patients were included, 110 of which were diagnosed with BA. Mean age at the time of MRI was 57.6 ± 34.4 d. There were positive correlations between fibrosis grade and PT and SR, even after adjusting age (all, P < 0.001). For the diagnosis of significant fibrosis (METAVIR grade F2-F4), the area under the ROC curve was 0.899 (95%CI: 0.840–0.941) for PT (cutoff, 4.2 mm), which was higher than 0.741 (95%CI: 0.664–0.808) for SR and 0.712 (95%CI: 0.634–0.782) for APRI (both, P < 0.001). For the diagnosis of cirrhosis (F4), the area under the ROC curve was the highest with SR as 0.790 (95%CI: 0.718–0.852).

CONCLUSION

Liver MRI findings of PT and SR are useful to assess clinically significant hepatic fibrosis (F2 and higher) in infants with cholestasis including BA.

Does Supersonic Shear Wave Elastography Help Differentiate Biliary Atresia from Other Causes of Cholestatic Hepatitis in Infants Less than 90 Days Old? Compared with Grey-Scale US

Purpose

To investigate the diagnostic performance of shear wave elastography (SWE) for measuring liver stiffness to identify and differentiate biliary atresia (BA) from cholestatic hepatitis in infants younger than 90 days.

Methods

A total of 138 infants younger than 90 days with cholestatic hepatitis were examined by SWE. The infants were subclassified into BA and nonbiliary atresia (non-BA) groups. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of hepatic Young's modulus measurements, the ultrasonic findings in the differential diagnosis of suspected BA, and the cut-off value to diagnose BA.

Results

In all infants with cholestatic hepatitis, the cut-off value of hepatic Young's modulus to differentiate the BA group from the non-BA group was 12.35 kPa and the area under the ROC curve (AUC) was 0.937, with a sensitivity of 84.3% and a specificity of 89.7%; nevertheless the AUC of the abnormal gallbladder (AbGB) was 0.940, with a sensitivity of 96.1% and a specificity of 92.0%. In the parallel test, triangular cord (TC) sign combined with AbGB had the best diagnostic performance and the AUC was 0.960, with a sensitivity of 100% and a specificity of 92.0%. In the serial test, SWE combined with AbGB achieved the best diagnostic performance; the AUC was 0.902, the sensitivity and specificity were 80.4% and 100%, respectively.

Conclusions

SWE could not only help differentiate BA from cholestatic hepatic diseases but also increase the diagnostic specificity when combined with grey-scale ultrasound in the serial test.

A periodic comparison of the survival and prognostic factors of biliary atresia after Kasai portoenterostomy: a single-center study in Korea

PURPOSE

We explored the chronologic changes in prognostic factors and clinical outcomes of Kasai portoenterostomy (KPE) for biliary atresia (BA).

METHODS

Patients undergoing KPE between 1997 and 2016 were analyzed retrospectively. Ninety-two consecutive patients who underwent KPE from 1997 to 2006 (Era 1) were compared with 150 patients who underwent KPE from 2007 to 2016 (Era 2) for clinical outcomes and prognostic factors.

RESULTS

The jaundice clearance rate increased by 8.8% (66.7% vs. 75.5% for Eras 1 and 2, respectively, p = 0.180), and the 5-year native liver survival (NLS) rate improved slightly (62.5% vs. 64.0% for Eras 1 and 2, respectively, p = 0.617) in Era 2. The hazard ratio for age at KPE (≥ 90 days) with regard to 5-year NLS and the odds ratio for age at KPE (< 90 days) with regard to jaundice clearance were both lower in Era 2 than in Era 1 (1.95 vs. 2.25 and 2.67 vs. 5.21, respectively).

CONCLUSION

The clinical outcomes improved over a period in a single surgeon's practice. We demonstrated that the impact of age at the time of KPE on operative outcomes became less significant over time with the increase in the single surgeon's experience and improvement in medical treatment for BA.

Predicting gastroesophageal varices through spleen magnetic resonance elastography in pediatric liver fibrosis

BACKGROUND

A recent retrospective study confirmed that hepatic stiffness and splenic stiffness measured with magnetic resonance elastography (MRE) are strongly associated with the presence of esophageal varices. In addition, strong correlations have been reported between splenic stiffness values measured with MRE and hepatic venous pressure gradients in animal models. However, most studies have been conducted on adult populations, and previous pediatric MRE studies have only demonstrated the feasibility of MRE in pediatric populations, while the actual clinical application of spleen MRE has been limited.

AIM

To assess the utility of splenic stiffness measurements by MRE to predict gastroesophageal varices in children.

METHODS

We retrospectively reviewed abdominal MRE images taken on a 3T system in pediatric patients. Patients who had undergone Kasai operations for biliary atresia were selected for the Kasai group, and patients with normal livers and spleens were selected for the control group. Two-dimensional spin-echo echo-planar MRE acquisition centered on the liver, with a pneumatic driver at 60 Hz and a low amplitude, was performed to obtain hepatic and splenic stiffness values. Laboratory results for aspartate aminotransferase to platelet ratio index (APRI) were evaluated within six months of MRE, and the normalized spleen size ratio was determined with the upper normal size limit. All Kasai group patients underwent gastroesophageal endoscopy during routine follow-up. The Mann-Whitney U test, Kendall's tau b correlation and diagnostic performance analysis using the area under the curve (AUC) were performed for statistical analysis.

RESULTS

The median spleen MRE value was 5.5 kPa in the control group (n = 9, age 9-18 years, range 4.7-6.4 kPa) and 8.6 kPa in the Kasai group (n = 22, age 4-18 years, range 5.0-17.8 kPa). In the Kasai group, the APRI, spleen size ratio and spleen MRE values were higher in patients with portal hypertension (n = 11) than in patients without (n = 11) (all P < 0.001) and in patients with gastroesophageal varices (n = 6) than in patients without (n = 16) (all P < 0.05), even though their liver MRE values were not different. The APRI (τ = 0.477, P = 0.007), spleen size ratio (τ = 0.401, P = 0.024) and spleen MRE values (τ = 0.426, P = 0.016) also correlated with varices grades. The AUC in predicting gastroesophageal varices was 0.844 at a cut-off of 0.65 (100% sensitivity and 75% specificity) for the APRI, and 0.844 at a cut-off of 9.9 kPa (83.3% sensitivity and 81.3% specificity) for spleen MRE values.

CONCLUSION

At a cut-off of 9.9 kPa, spleen MRE values predicted gastroesophageal varices as well as the APRI and spleen size ratio in biliary atresia patients after the Kasai operation. However, liver MRE values were not useful for this purpose.

Noninvasive Evaluation of Liver Fibrosis and Portal Hypertension After Successful Portoenterostomy for Biliary Atresia

We investigated noninvasive follow‐up markers for histologic liver fibrosis and portal hypertension (PH) in patients with biliary atresia after successful portoenterostomy (PE). Among children with bilirubin <20 µmol/L after PE (n = 39), Metavir fibrosis stage was evaluated at PE and in follow‐up protocol liver biopsies (n = 83). PH was defined as endoscopically confirmed esophageal varices or thrombocytopenia associated with splenomegaly. The accuracy of liver biochemistry and stiffness in detecting liver fibrosis and PH was analyzed by the area under the receiving operating characteristic curve (AUROC) and multiple regression models. During a median native liver survival of 8.3 years (interquartile range 2.5‐10.8 years), cirrhosis (Metavir F4) had developed in 51% of patients and PH in 54% of patients. Cirrhosis was equally common in all age tertiles of 1.2‐2.1 years (n = 10/27), 3.9‐5.8 years (n = 12/28), and 9.0‐14 years (n = 12/28). In the two oldest age tertiles, histologic liver fibrosis had progressed further in patients with PH than without PH (P < 0.001). PH was accurately predicted by the aspartate aminotransferase‐to‐platelet ratio index (APRI) (cutoff, 0.70; AUROC, 0.92), bile acids (cutoff, 49 µmol/L; AUROC, 0.91), and liver stiffness (cutoff, 16.9 kPa; AUROC, 0.89; P < 0.001 each) across all age tertiles. Liver stiffness was the most accurate predictor of cirrhosis overall (AUROC, 0.82; P < 0.001), whereas bilirubin was >11 µmol/L in the youngest tertile (AUROC, 0.91; P < 0.001), bile acids was >80 µmol/L in the middle tertile (AUROC, 0.81; P = 0.009), and liver stiffness was >24 kPa in the oldest age tertile (AUROC, 0.96; P = 0.002). Conclusion: After successful PE, development of PH associates with progression of liver fibrosis and can be accurately detected by APRI and stiffness. Liver stiffness most accurately identified cirrhosis in older children, whereas biochemical markers of cholestasis closely reflected histologic cirrhosis in younger children.

Technical performance of shear wave elastography for measuring liver stiffness in pediatric and adolescent patients: a systematic review and meta-analysis

OBJECTIVE

To assess the technical performance (proportion of technical failure and unreliable measurements) of shear wave elastography (SWE) for assessing liver stiffness in pediatric and adolescent patients.

METHODS

We searched Ovid-MEDLINE and EMBASE databases for eligible studies and selected original articles investigating transient elastography (TE), point shear wave elastography (pSWE), or two-dimensional SWE (2D-SWE) for measuring liver stiffness in pediatric and adolescent patients. A quantitative synthesis of studies reporting technical failures and/or unreliable measurements of TE, pSWE, or 2D-SWE is presented. Meta-analytic pooling was conducted using the random effects model. Meta-regression analysis was conducted to explore potential causes of heterogeneity.

RESULTS

Forty of 69 studies (58%) provided technical performance information. Technical failure data were reported in 3 TE, 6 pSWE, and 8 2D-SWE studies. Unreliable measurement data were provided in 21 TE, 4 pSWE, and 1 2D-SWE study. The pooled proportion of unreliable measurements of TE was 12.1%. Meta-regression analysis showed that the study population size and readers' blinding to pathologic results affected the study's heterogeneity. The pooled proportions of technical failure during pSWE and 2D-SWE were 4.1% and 2.2%, respectively, demonstrating no significant difference between the techniques.

CONCLUSIONS

We reviewed the technical performance of SWE, especially the rate of unreliable measurements from TE studies and rates of technical failure from pSWE and 2D-SWE studies. Considering the importance of technical performance for clinical validation of SWE, numbers of and reasons for technical failure and unreliable measurements should be reported in future studies. Further efforts are necessary to standardize SWE reliability criteria.

KEY POINTS

• Most TE studies reported rate of unreliable measurements, whereas pSWE and 2D-SWE studies were likely to report rates of technical failure. • The pooled proportion of unreliable measurements of TE was 12.1%. • The pooled proportions of technical failure during pSWE and 2D-SWE were 4.1% and 2.2%, respectively, demonstrating no significant difference between the techniques.

Predictors of Successful Kasai Portoenterostomy and Survival with Native Liver at 2 Years in Infants with Biliary Atresia

OBJECTIVES

Kasai portoenterostomy (KPE) is the primary treatment for biliary atresia (BA) with subsequent liver transplantation in failed cases. The aim of this work was to study the outcome of KPE in children with BA and identify the factors predicting a successful KPE.

METHODS

Children diagnosed with BA and undergoing KPE between January 2010 and January 2018 were included in the study. A successful KPE was defined as decrease in bilirubin to less than 2 mg/dL at 6 months after KPE. Factors affecting the outcome (successful KPE and survival with native liver [SNL] at 2 years) were evaluated by logistic regression.

RESULTS

A total of 79 children with post-KPE BA were included. Successful KPE was achieved in 29 (36.7%) of 79 children undergoing KPE. The data for survival with native liver at 2 years were available for 61 children as 9 were lost to follow up before 2 years and another 9 were aged less than 2 years at the time of analysis. Twenty-seven (44.3%) of these 61 survived with their native liver at 2 years. On logistic regression analysis, lower age at KPE, use of postoperative steroids and absence of cholangitis were significant predictors of a successful KPE. A successful KPE at 6 months was the lone independent predictor of SNL at 2 years in these children.

CONCLUSION

Early age at KPE, use of postoperative steroid and prevention of cholangitis can result in successful KPE. Those with successful KPE are likely to survive with their native liver at 2 years.

Advances in diagnosis of chronic liver diseases in pediatric patients

BACKGROUND

Chronic liver diseases (CLD) present important clinical problem in children with various age-dependent causes. Nonalcoholic fatty liver disease (NAFLD) with its increasing prevalence is a major problem with regard to its timely recognition and the need for long-term disease monitoring. At present, a perfect non-invasive method for the evaluation of liver fibrosis is not available.

METHODS

A non-systematic literature search was performed to summarize the current knowledge about transient elastography (TE) with controlled attenuation parameter (CAP) in children with CLD. Ovid MEDLINE, Ovid EMBASE, Google scholar, and The Cochrane Library databases were searched for relevant articles evaluating TE in the pediatric population.

RESULTS

Normal values of liver stiffness measurements (LSM) according to the age are given, as well as the advantages and disadvantages of the method. The utility of TE in specific liver disease in pediatric population is summarized.

CONCLUSIONS

TE with CAP is a valuable non-invasive method for the liver-damage assessment. Clinical interpretation of TE results should be made in parallel with the assessment of the patient's demographics, disease etiology, and essential laboratory parameters.

Feasibility of 2-D ultrasound shear wave elastography of fetal lungs in case of threatened preterm labour: a study protocol

INTRODUCTION

2-D ultrasound shear wave elastography (SWE) could be considered as a new noninvasive tool for monitoring fetal lung development based on evaluation of mechanical properties during pregnancy. Interesting results are available concerning the use of SWE on developing organs, especially on premature infants and animal models. The main objective in this study is to evaluate the feasibility of 2-D SWE in human fetal lungs between 24 and 34 weeks of gestation (WG). The secondary objective is to modellise fetal lung-to-liver elastography ratio (LLE ratio) and to assess variations between normal lung and lung surfactant-enriched after a corticosteroids course indicated for a threatened preterm labour (TPL).

METHODS/DESIGN

A prospective case-control study will be performed between 24 and 34 WG. Fetal lungs and liver will be explored by SWE into two groups: fetuses of women with an uncomplicated pregnancy (control group) and fetuses of women with a TPL requiring administration of corticosteroids (cases group). LLE ratio will be defined as the value of the lung elasticity divided by the value of the liver elasticity.Primary judgement criterion is the value of elasticity modulus expressed in kilopascal. Lungs and liver will be explored through three measurements to define the most reproducible regions with the lowest intra- and inter-observer variability. Feasibility will be evaluated by assessing the number of examinations performed and the number of examinations with interpretable results. Intra- and inter-observer reproducibility will be evaluated by means of the intra-class correlation coefficient.

ETHICS AND DISSEMINATION

Approval of the study protocol was obtained from the human ethical research committee (Comité de Protection des Personnes EST II, process number 15/494) and the French National Agency for Medicines and Health Products Safety (process number 2015-A01575-44). All participants will sign a statement of informed consent.

TRIAL REGISTRATION NUMBER

NCT02870608; Recruiting.

Limitations and opportunities of non-invasive liver stiffness measurement in children

Changes in liver structure are an important issue in chronic hepatopathies. Until the end of the 20^th century, these changes could only be determined by histological analyses of a liver specimen obtained via biopsy. The well-known limitations of this technique (i.e., pain, bleeding and the need for sedation) have precluded its routine use in follow-up of patients with liver diseases. However, the introduction of non-invasive technologies, such as ultrasound and magnetic resonance imaging, for measurement of liver stiffness as an indirect marker of fibroses has changed this situation. Today, several non-invasive tools are available to physicians to estimate the degree of liver fibrosis by analysing liver stiffness. This review describes the currently available tools for liver stiffness determination that are applicable to follow-up of liver fibrosis/cirrhosis with established clinical use in children, and discusses their features in comparison to the “historical” tools.

Liver stiffness measurements with supersonic shear wave elastography in the diagnosis of biliary atresia: a comparative study with grey-scale US

OBJECTIVES

To prospectively assess the diagnostic performance of supersonic shear wave elastography (SSWE) in identifying biliary atresia (BA) among infants with conjugated hyperbilirubinaemia by comparing this approach with grey-scale ultrasonography (US).

METHODS

Forty infants were analysed as the control group to determine normal liver stiffness values. The use of SSWE values for identifying BA was investigated in 172 infants suspected of having BA, and results were compared with the results obtained by grey-scale US. The Mann-Whitney U test, unpaired t-test, Spearman correlation and linear regression were also performed.

RESULTS

The success rates of SSWE measurements in the control and study group were 100% (40/40) and 96.4% (244/253), respectively. Age, direct bilirubin, and indirect bilirubin all significantly correlated with SSWE in the liver (all P < 0.001). Linear regression showed that age had a greater effect on SSWE values than direct or indirect bilirubin. The diagnostic performance of liver stiffness values in identifying BA was lower than that of grey-scale US (area under the receiver operating characteristic curve [AUC], 0.790 vs 0.893, P < 0.001).

CONCLUSIONS

SSWE is feasible and valuable in differentiating BA from non-BA. However, its diagnostic performance does not exceed that of grey-scale US.

KEY POINTS

• SSWE could be successfully performed in an infant population. • For infants, the liver stiffness will increase as age increases. • SSWE is potentially useful in assessing infants suspected of biliary atresia. • SSWE is inferior to grey-scale US in identifying biliary atresia.

Biliary atresia: Where do we stand now?

The pathway from clinical suspicion to establishing the diagnosis of biliary atresia in a child with jaundice is a daunting task. However, investigations available help to point towards the correct diagnosis in reasonable time frame. Imaging by Sonography has identified several parameters which can be of utility in the diagnostic work up. Comparison of Sonography with imaging by Nuclear medicine can bring out the significant differences and also help in appropriate imaging. The battery of Biochemical tests, available currently, enable better understanding of the line-up of investigations in a given child with neonatal cholestasis. Management protocols enable standardized care with optimal outcome. The place of surgical management in biliary atresia is undisputed, although Kasai procedure and primary liver transplantation have been pitted against each other. This article functions as a platform to bring forth the various dimensions of biliary atresia.

Ultrasound Elastography Is Useful for Evaluation of Liver Fibrosis in Children-A Systematic Review

OBJECTIVES

Adult studies have proven ultrasound elastography as a validated measure of liver fibrosis. The present study aimed to review the available literature on ultrasound elastography in children to evaluate the ability of the method to distinguish healthy from fibrotic liver tissue and investigate whether cutoff values for liver fibrosis in children have been established.

METHODS

A literature search was performed in MEDLINE, EMBASE, the Cochrane Library, and Web of Science to identify studies on ultrasound elastography of the liver in children. Only original research articles in English concerning ultrasound elastography in children with and without liver disease, younger than 18 years, were included. All reference lists of the included articles were hand-searched for further references.

RESULTS

Twenty-seven articles were included. Elastography in children without liver disease was investigated in 14 studies and were comparable to those existing for adults. Twelve studies compared elastography with liver biopsy in children with liver disease and found that cirrhosis was correctly diagnosed, whereas it was more difficult to assess severe fibrosis correctly. For the distinction between no, mild, and moderate fibrosis in children with liver disease the method was less accurate. Ultrasound elastography was able to differentiate between children with and without liver fibrosis. In children without liver disease ultrasound, elastography showed consistent liver stiffness values comparable to those found in adults. No fibrosis-specific cutoffs were proposed.

CONCLUSIONS

Ultrasound elastography was able to diagnose cirrhosis, distinguish healthy from fibrotic liver tissue, and showed consistent liver stiffness values in children without liver disease.

Supersonic shearwave elastography in the assessment of liver fibrosis for postoperative patients with biliary atresia

To explore an effective noninvasive tool for monitoring liver fibrosis of children with biliary atresia (BA) is important but evidences are limited. This study is to investigate the predictive accuracy of supersonic shearwave elastography (SSWE) in liver fibrosis for postoperative patients with BA and to compare it with aspartate aminotransferase to platelet ratio index (APRI) and fibrosis-4 (FIB-4). 24 patients with BA received SSWE and laboratory tests before scheduled for liver biopsy. Spearman rank coefficient and receiver operating characteristic (ROC) were used to analyze data. Metavir scores were F0 in 3, F1 in 2, F2 in 4, F3 in 7 and F4 in 8 patients. FIB-4 failed to correlate with fibrosis stage. The areas under the ROC curves of SSWE, APRI and their combination were 0.79, 0.65 and 0.78 for significant fibrosis, 0.81, 0.64 and 0.76 for advanced fibrosis, 0.82, 0.56 and 0.84 for cirrhosis. SSWE values at biopsy was correlated with platelet count (r = -0.426, P = 0.038), serum albumin (r = -0.670, P < 0.001), total bilirubin (r = 0.419, P = 0.041) and direct bilirubin levels (r = 0.518, P = 0.010) measured at 6 months after liver biopsy. Our results indicate that SSWE is a more promising tool to assess liver fibrosis than APRI and FIB-4 in children with BA.

Utility of Shear Wave Elastography for Differentiating Biliary Atresia From Infantile Hepatitis Syndrome

OBJECTIVES

The purpose of this study was to investigate the potential utility of shear wave elastography (SWE) for diagnosis of biliary atresia and for differentiating biliary atresia from infantile hepatitis syndrome by measuring liver stiffness.

METHODS

Thirty-eight patients with biliary atresia and 17 patients with infantile hepatitis syndrome were included, along with 31 healthy control infants. The 3 groups underwent SWE. The hepatic tissue of each patient with biliary atresia had been surgically biopsied. Statistical analyses for mean values of the 3 groups were performed. Optimum cutoff values using SWE for differentiation between the biliary atresia and control groups were calculated by a receiver operating characteristic (ROC) analysis.

RESULTS

The mean SWE values ± SD for the 3 groups were as follows: biliary atresia group, 20.46 ± 10.19 kPa; infantile hepatitis syndrome group, 6.29 ± 0.99 kPa; and control group, 6.41 ± 1.08 kPa. The mean SWE value for the biliary atresia group was higher than the values for the control and infantile hepatitis syndrome groups (P < .01). The mean SWE values between the control and infantile hepatitis syndrome groups were not statistically different. The ROC analysis showed a cutoff value of 8.68 kPa for differentiation between the biliary atresia and control groups. The area under the ROC curve was 0.997, with sensitivity of 97.4%, specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 96.9%. Correlation analysis suggested a positive correlation between SWE values and age for patients with biliary atresia, with a Pearson correlation coefficient of 0.463 (P < .05).

CONCLUSIONS

The significant increase in liver SWE values in neonates and infants with biliary atresia supports their application for differentiating biliary atresia from infantile hepatitis syndrome.

Development and Validation of a Novel Fibrosis Marker in Biliary Atresia during Infancy

OBJECTIVES

Most biliary atresia (BA) patients suffer from liver fibrosis and often require liver transplantation. The aim of this study was to develop and validate a novel fibrosis marker for BA patients aged <1 year-the infant BA liver fibrosis (iBALF) score-subsequent to the previously reported fibrosis marker for BA patients aged ≥1 year.

METHODS

From three institutions for pediatric surgery, BA patients and their native liver histology examinations performed at the age of <1 year were retrospectively identified and assigned to a development cohort (58 patients and 73 examinations) or validation cohort (92 patients and 117 examinations) according to their institutions. Histological fibrosis stages (F0-F4), blood test results, and clinical information at the time of liver histology examination were reviewed. The iBALF score was determined using multivariate ordered logistic regression analysis and was assessed for its associations with histological fibrosis stages.

RESULTS

The iBALF score equation was composed of natural logarithms, including serum total bilirubin level, blood platelet counts, and days of age. The score revealed a strong correlation with fibrosis stage (r=0.80 and 0.73 in the development and validation cohorts, respectively; P<0.001). The areas under the receiver-operating characteristic curves for diagnosing each fibrosis stage were 0.86-0.94 in the development cohort and 0.86-0.90 in the validation cohort (P<0.001), indicating good diagnostic power. In addition, no patient with an iBALF score >6 (equivalent to F4) at the initial surgery survived with their native liver at 1 year of age (n=9).

CONCLUSIONS

The iBALF score that was developed was a good noninvasive marker of native liver fibrosis for BA patients aged <1 year.

Quantitative Shear-Wave Elastography of the Liver in Preterm Neonates with Intra-Uterine Growth Restriction

The feasibility and reproducibility of liver stiffness measurements using Supersonic Shear-wave Imaging (SSI) in preterm neonate have not been reported. Our aim was to determine if liver stiffness differs between intra-uterine growth restriction (IUGR) and appropriate for gestational age (AGA) preterm infants with/without cholestasis. We measured liver stiffness (in kPa) in 45 AGA and 18 IUGR preterm infants, and assessed reproducibility in 26 preterms using Intraclass Correlation Coefficients (ICC) and Bland-Altman tests. Liver stiffness values were compared between AGA and IUGR with and without cholestasis and correlated with birth weight. Measurements showed high reproducibility (ICC = 0.94–0.98 for intra-operator, 0.86 for inter-operator) with good agreement (95% limits: -1.24 to 1.24 kPa). During the first postnatal week, liver stiffness was higher in IUGR (7.50 ±1.53 kPa) than in AGA infants (5.11 ±0.80 kPa, p<0.001). After day 8, liver stiffness remained unchanged in AGA but increased progressively in IUGR infants (15.57 ±6.49 kPa after day 21). Liver stiffness was higher in IUGR neonates with cholestasis (19.35 ± 9.80 kPa) than without cholestasis (7.72 ± 1.27 kPa, p<0.001). In conclusion, quantitative liver SSI in preterms is feasible and reproducible. IUGR preterms who will develop cholestasis present high liver stiffness even at birth, before biological cholestasis occurs.

Is liver biopsy still needed in children with chronic viral hepatitis?

Liver biopsy is a standard method used for obtaining liver tissue for histopathological evaluation. Since reliable serological and virological tests are currently available, liver biopsy is no longer needed for the etiological diagnosis of chronic hepatitis B and C. However, liver histology remains the gold standard as a prognostic tool, providing information about the liver disease progression (grading of necroinflammatory activity and staging of fibrosis) and serving clinicians in the management and therapeutic decisions. In general, histopathological evaluation is indicated before starting the antiviral treatment. Main limitations of the liver biopsy include its invasive and painful procedure, sampling errors and the inter- and intra-observer variability. In addition, indications for the liver biopsy in pediatric patients with chronic viral hepatitis were questioned recently, and efforts have been made toward the development of non-invasive methods as an alternative to the liver biopsy. The most commonly used methods are novel imaging studies (elastography) and combinations of biomarkers. However, to date, none of these tests was validated in children with chronic viral hepatitis. In this review, we present the current status of the liver biopsy in the management of chronic viral hepatitis B and C in pediatric population, including specific indications, complications, contraindications, problems, limitations, and alternative non-invasive methods.

Contribution of acoustic radiation force impulse (ARFI) elastography to the ultrasound diagnosis of biliary atresia

BACKGROUND

Children with biliary atresia rapidly develop liver fibrosis secondary to inflammatory destruction of the biliary tract. Noninvasive detection of liver fibrosis in neonatal/infantile cholestasis is an additional criterion for the diagnosis of biliary atresia, leading to prompt surgical exploration.

OBJECTIVE

To assess the value of US with acoustic radiation force impulse (ARFI) elastography to detect biliary atresia in the workup of neonatal/infantile cholestasis.

MATERIALS AND METHODS

In this retrospective study, 20 children with cholestasis suspected of having biliary atresia were investigated by US and ARFI. We evaluated the association between US findings and the diagnosis of biliary atresia and with two scores of liver fibrosis obtained from liver biopsy.

RESULTS

In univariate analyses, gallbladder size, triangular cord sign, spleen size and ARFI values were found to be associated with biliary atresia, though only the triangular cord sign remained significant when elevated gamma glutamyltransferase (GGT) was included as a predictor. In contrast, spleen size and ARFI correlated with the degree of liver fibrosis on biopsy (r > 0.70, P < 0.001), which remained significant when gamma glutamyltransferase elevation was included as a predictor.

CONCLUSION

The addition of ARFI to a standard abdominal US in the initial workup of the neonate with possible infantile cholestasis can provide reliable information on liver fibrosis and help in the diagnosis of biliary atresia.

Contrast-enhanced ultrasonography for the evaluation of liver fibrosis after biliary obstruction

AIM: To investigate perfusion change in contrast-enhanced ultrasonography (CEUS) to evaluate liver fibrosis based on biliary obstruction using an animal model.

METHODS: New Zealand white rabbits (3-4 kg) underwent bile duct ligation to form a biliary obstruction model. We performed liver CEUS and laboratory tests on the day before the operation (day 0) and every 7 postoperative days until the rabbits were sacrificed. After CEUS, signal intensity of liver parenchyma with a time-intensity curve was analyzed. Perfusion parameters were automatically calculated from region-of-interests, including peak signal intensity, mean transit time, area under the curve and time to peak. Histological grades of liver fibrosis were assessed according to the Metavir score system immediately after sacrifice. Generalized estimating equations were used to analyze the association between liver fibrosis grades and perfusion parameters for statistical analysis. The perfusion parameters were measured on the last day and the difference between day 0 and the last day were evaluated.

RESULTS: From the nine rabbits, histological grades of liver fibrosis were grade 1 in one rabbit, grade 2 and 3 in three rabbits each, and grade 4 in two rabbits. Among the four CEUS parameters, only the peak signal intensity measured on the last day demonstrated a significant association with liver fibrosis grades (OR = 1.392, 95%CI: 1.114-1.741, P = 0.004). The difference in peak signal intensity between day 0 and the last day also demonstrated an association with liver fibrosis (OR = 1.191, 95%CI: 0.999-1.419, P = 0.051). The other parameters tested, including mean transit time, area under the curve, and time to peak, showed no significant correlation with liver fibrosis grades.

CONCLUSION: This animal study demonstrates that CEUS can be used to evaluate liver fibrosis from biliary obstruction using peak signal intensity as a parameter.

Liver biopsy in children 2014: who, whom, what, when, where, why?

Liver biopsy is the standard procedure for obtaining hepatic tissue for histopathological examination. The three major techniques are percutaneous, transvenous, and laparoscopic/open biopsy, with either cutting or suction needles. The indications for liver biopsy are shifting as knowledge of etiologies, non-invasive biomarker alternatives, and treatment options in paediatric liver disease expand. This mini-review presents specific indications, alternative approaches, methods, complications, and contraindications for paediatric liver biopsy.