The degree of spleen stiffness measured on acoustic radiation force impulse elastography predicts the severity of portal hypertension in patients with biliary atresia after portoenterostomy

Spleen shear wave elastography measurements do not correlate with histological grading of liver fibrosis in Fontan physiology: a preliminary investigation

BACKGROUND

Elevated spleen stiffness may be seen in patients with portal hypertension due to cirrhosis. In patients with Fontan physiology, elevated liver stiffness has been shown to correlate poorly with liver fibrosis. It is unknown whether spleen stiffness may instead serve as a surrogate marker of liver fibrosis in these patients.

OBJECTIVE

To compare spleen stiffness determined by shear wave elastography (SWE) with histological findings of an ultrasound-guided liver biopsy in patients who had undergone Fontan palliation as a potential surrogate for Fontan-associated liver disease.

MATERIALS AND METHODS

This was an IRB-approved single-center, retrospective study. Patients with Fontan palliation who had undergone both a spleen SWE study and a percutaneous liver biopsy between 2016 and 2020 were included. Biopsy, performed during cardiac catheterization, within 3 months of the SWE was required for inclusion. Using Kruskal-Wallis tests, spleen stiffness was compared with three liver biopsy scoring methods: Ishak, METAVIR, and congestive hepatic fibrosis score (CHFS). When available, Pearson's correlation was also used to compare collagen deposition determined using Sirius Red stain (%SR) with SWE values. A P-value < 0.05 was considered statistically significant.

RESULTS

Twenty-two patients (15 males) were included in the study, with a median age of 17 years (IQR is 14.8-20.5 years; age range: 7 years to 30.2 years). The median spleen stiffness was 2.94 m/s (IQR: 2.57-3.61 m/s; range: 1.48-4.27 m/s). The median Fontan pressure was 11 mm Hg (IQR: 10-13.3 mm Hg; range: 7-19 mm Hg) obtained within a median of 10 days (IQR: 1-41 days) of SWE. Splenic stiffness did not correlate with the extent of fibrosis determined by histology (all P > 0.05). There was also no statistically significant correlation between the %SR staining and SWE-determined spleen stiffness (Pearson's correlation of 0.165, P = 0.59, n = 13).

CONCLUSIONS

In this preliminary study, SWE spleen stiffness values did not correlate with biopsy-determined scoring of liver fibrosis in patients with Fontan physiology.

Early detection of hepatobiliary involvement in cystic fibrosis: Biomarkers, radiologic methods, and genetic influences

Cystic fibrosis-related hepatobiliary involvement (CFHBI) is a term used to describe a spectrum of hepatobiliary involvement ranging from a transient elevation of transaminase levels to advanced cystic fibrosis-associated liver disease (aCFLD). While CFHBI is common among people with cystic fibrosis (PwCF), aCFLD is rare impacting only approximately 5%-10% of the CF population. After respiratory/cardiorespiratory issues and transplant-related complications, aCFLD is now the 4th leading cause of mortality among PwCF. Additionally, aCFLD is an independent predictor of all-cause mortality and is associated with significant morbidity. Despite this recognition, our ability to predict those patients at greatest risk for aCFLD, identify early aCFLD, and monitor the incremental progression of CFHBI is lacking. Here, we review the strengths and weaknesses of the common biomarkers and imaging modalities used in the evaluation and monitoring of CFHBI, as well as the current understanding of genetic modifiers related to aCFLD.

Shear Wave Ultrasonographic Elastography in Pediatric Spleens and Its Role in Differential Diagnosis

Shear wave elastography (SWE) has become popular in clinical practice for many diseases. However, there is not adequate research on spleen-related diseases. This study aimed to investigate the potential of quantitative values obtained through SWE in evaluating spleen pathologies in the pediatric population and to demonstrate its performance to differentiate splenomegaly-related diseases. The research group retrospectively included children with pathological diagnoses related to the spleen from November 2016 to April 2021, and they were categorized into three groups, including portal hypertension (PH), benign lymphoid hyperplasia (BLH), and malignant infiltration (MI). Spleen sizes and parenchymal stiffness were also calculated for each group. Subsequently, mean spleen stiffness in each group was compared with normal values within the same age group. In total, 2781 children (1379 children for the study group; 1402 children for the control group) were enrolled in the study. The highest stiffness was observed in the PH group, which is statistically higher than others (p < 0.05). Although the mean spleen stiffness in the group with BLH was higher than the control and MI group, the difference was not statistically significant (p = 0.08). The mean stiffness in the group with MI was significantly lower than both the control group (p = 0.005) and PH (p = 0.01). In conclusion, using SWE in the differential diagnosis of etiologies causing splenomegaly could make an important contribution.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD)

PURPOSE

Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD).

METHODS

This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score.

RESULTS

Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers.

CONCLUSION

Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

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.

A Nomogram Predicting the Prognosis of Children With Biliary Atresia After Hepatoportoenterostomy

Background: Although Kasai portoenterostomy (KPE) is performed timely for most children with biliary atresia (BA), the native liver survival (NLS) is still poor due to the progressive liver fibrosis. Many children have to receive liver transplantation (LT) within 2 years after KPE. Early prediction of the prognosis permits the implementation of prophylactic treatments for BA children. However, studies about the prediction are limited. Objective: The purpose of this study is to establish a nomogram to predict the prognosis of BA children within 2 years after KPE. Methods: The follow-up data of 151 BA children were retrospectively reviewed, and were randomly divided into a training cohort for constructing a nomogram (n = 103) and a validation cohort (n = 48). In the training cohort, patients were divided into Group A and Group B according to whether death or LT were observed within 2 years post-KPE. Multivariate Cox regression based on the baseline characteristics, liver function indicators and LSM (liver stiffness measurement) values at KPE and 3 months after KPE was utilized for the establishment of the nomogram in predicting the prognosis of BA within 2 years after KPE. The discrimination and calibration of the nomogram were internally and externally validated. Results: Fifty-six BA children were included in Group A and 47 were included in group B. Age at KPE, METAVIR score F4, LSM at 3 months, first onset of cholangitis within 3 months, and jaundice clearance time were the independent predictors for the prognosis of BA children within 2 years after KPE (all P < 0.05). The developed nomogram based on these independent predictors showed good discrimination and calibration by the internal and external validation. Its performance was better than each predictor in predicting the prognosis (all P < 0.05). Conclusions: The established nomogram based on the indicators from the first 3 months after KPE may be useful for predicting the prognosis of BA children within 2 years post-KPE and helpful for the consideration of LT.

Evaluation of spleen stiffness in healthy volunteers using point shear wave elastography

INTRODUCTION AND OBJECTIVES

This study aims to measure the values of spleen stiffness (SS) in healthy subjects, the inter-operator agreement in SS measurement, and to detect statistically significant correlations between SS and age, sex, weight, BMI, portal vein dynamics and splenic dimensions.

MATERIALS AND METHODS

The study included 100 healthy volunteers who had no substantial alcohol intake (<30g/daily for man, <20g/daily women), were negative on hepatitis B, hepatitis C, HIV blood serology, and had any history of lymphoproliferative disorders. Abdominal ultrasound, liver and spleen elastography were performed on each patient to search for focal splenic lesions, bile tract or portal vein dilatation, moderate/severe liver steatosis, and to measure liver and spleen stiffness.

RESULTS

The mean value was 18.14 (±3.08) kPa. In the group of men (n=49), the mean was 17.73 (±2.91) kPa, whereas in the group of women (n=51) it was 16.72 (±3.32) kPa. Statistical analyses showed no correlation between spleen stiffness and sex, age, weight, and BMI. Regarding their splenoportal axis, statistically significant differences in SS were found in the means of the two subgroups of subjects stratified by their portal flow velocity (p=0.003) and spleen area (p<0.001). Spearman's rank showed a weak association between SS and portal flow velocty (r=0.271) and splenic area (r=-0.237). ICC showed excellent (0.96) inter-operator agreement and Bland-Altman plot demonstrated no systematic over/under-estimation of spleen stiffness values.

CONCLUSIONS

Our results may serve as a reference point in the evaluation of SS especially in patients affected by advanced liver disease.

Clinical implications of serum Mac-2-binding protein (M2BPGi) during regular follow-up of patients with biliary atresia

PURPOSE

The Mac-2-binding protein glycosylation-modified isomer (M2BPGi) is a new marker for progression of hepatic fibrosis. We examined the relationship between serum M2BPGi levels and liver histological findings in patients with biliary atresia (BA) who were not transplant candidates.

METHODS

Patients with BA who were not transplant candidates with good liver function were included. We examined M2BPGi levels and histological findings in relation to other laboratory markers of liver fibrosis, including aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and type IV collagen 7s domain. Liver fibrosis was evaluated based on the METVIR score.

RESULTS

37 patients were included. The median age was 18 years (range 3-38 years). M2BPGi values ranged from 0.3 to 6.9 cutoff index (COI) (median 1.6). The degree of liver fibrosis varied with M2BPGi level. For predicting cirrhosis (F4) and advanced liver fibrosis (≥ F3), M2BPGi had higher areas under the curve (AUCs; 0.93, respectively) with cutoff COIs of 1.84 and 1.67, respectively, than for the four conventional markers for fibrosis.

CONCLUSION

M2BPGi is a novel marker for liver fibrosis in patients with BA. It is especially useful for following patients with BA with a native liver and supporting liver biopsy interpretation findings.

Clinical applications of spleen ultrasound elastography - a review

In the last few years, notable technical progress has taken place in ultrasound elastography. Qualitative methods have been replaced by quantitative ones, such as: transient elastography, acoustic radiation force impulse and shear wave elastography. Owing to the fact that the spleen is superficially located, it is possible to obtain reliable measuring accuracy of its hardness using sonoelastography. Lately, many researchers have been investigating how spleen elasticity changes in patients infected with hepatitis B virus or hepatitis C virus and in patients suffering from liver fibrosis, portal hypertension, esophageal varices or myelofibrosis. In this article, we review the role and current status of accessible qualitative ultrasound elastography methods, including recent advances in the evaluation of spleen stiffness and its clinical utility. As study results demonstrate, spleen stiffness correlates with liver fibrosis and is helpful in determining the level of fibrosis in the METAVIR scoring system. In patients infected with hepatitis B virus or hepatitis C virus, spleen stiffness increases even when liver elasticity remains unaltered. Furthermore, it is useful in diagnosing portal hypertension or predicting existence of esophageal varices. Moreover, in patients suffering from biliary atresia after Kasai portoenterostomy, spleen sonoelastography may be helpful in selecting patients for liver transplantation as well as for choosing the best strategy for portal vein reconstruction before liver transplantation. In myelofibrosis, spleen stiffness correlates with bone marrow fibrosis and may be used to assess the response to treatment. Spleen sonoelastography is also useful in the monitoring of transjugular intrahepatic portosystemic shunt function.

Non-invasive evaluation of portal hypertension using ultrasound elastography

Portal hypertension (PH) leads to serious complications, such as bleeding from gastroesophageal varices, ascites and portosystemic encephalopathy in patients with chronic liver disease (CLD). Gold standard methods for assessing PH and its complications include the measurement of hepatic venous pressure gradient and endoscopy; however, these are invasive, expensive and not available at all centres. Therefore, non-invasive alternatives have been the subject of extensive investigation over the last 20years. The present review focuses on the role of ultrasound elastography - a novel group of non-invasive techniques used to measure stiffness in target organs. In the context of CLD these methods are used to identify the presence of PH, its severity, and the risk of PH-related complications. The rationale, accumulated evidence, advantages and limitations of liver and spleen stiffness measurements evaluated by different ultrasound elastography techniques in patients with advanced CLD is discussed. Recent data regarding the use of ultrasound elastography techniques in patients with non-cirrhotic forms of PH are also described.

Liver Stiffness Measured by Shear-wave Elastography for Evaluating Intrahepatic Portal Hypertension in Children

OBJECTIVES

The aim of the study was to correlate liver stiffness (LS) and hepatic venous-pressure gradient (HVPG) and to evaluate the diagnostic performance of shear-wave elastography (SWE) for predicting clinically significant portal hypertension in children with suspected liver diseases, in consideration of the reliability criteria.

METHODS

We identified 33 SWEs from 32 children who underwent HVPG measurement within 2 weeks between June 2012 and October 2015. The correlation between LS and HVPG was assessed. The diagnostic performance for predicting clinically significant portal hypertension (HVPG ≥ 10 mmHg) was assessed using the receiver-operating characteristic curve. Reliable measurement was evaluated based on the coefficient of variation (CV).

RESULTS

LS was significantly correlated with HVPG (r = 0.742, P < 0.001). The area under the receiver-operating characteristic curve for predicting clinically significant portal hypertension was 0.914, and the best cutoff value of 18.4 kPa showed sensitivity of 87.5% and specificity of 84.0%. LS measurements having CV ≤ 0.2 were significantly correlated with HVPG (r = 0.774, P < .001), whereas those having CV > 0.2 did not show a significant correlation with HVPG (r = 0.598, P = 0.089).

CONCLUSIONS

SWE had excellent diagnostic performance for predicting clinically significant portal hypertension in children with suspected liver diseases. LS measurements having CV ≤ 0.2 may possibly be used as a reliability criterion in SWE measurement.

Acoustic radiation force impulse sonography in assessing children with biliary atresia for liver transplantation

BACKGROUND

Children with biliary atresia are prone to developing progressive hepatic fibrosis and biliary cirrhosis following the Kasai operation. The only treatment is liver transplantation.

OBJECTIVE

To assess liver fibrosis by acoustic radiation force impulse elastography (ARFI) in children who had Kasai operation, with the goal of identifying an ARFI value cut-off for children requiring liver transplantation.

MATERIALS AND METHODS

Of the 32 post-Kasai children included, 19 were transplanted or listed for transplantation (group A), while 13 were not on the list during their follow-up (group B). We recorded biopsies, blood samples and ARFI values over time, including at Kasai operation and at transplantation. We estimated an association between groups and continuous variables using generalized estimating equations, and we compared categorical variables using the Fisher exact test.

RESULTS

Portal hypertension signs were similar in both groups, whereas ARFI values were higher in group A (mean±standard deviation=3.3±1.2 m/s) than in group B (2.0±0.7 m/s; P=.0003). Eighteen of 19 (94.7%) children in group A and 6/13 (46.2%) children in group B presented with two consecutive ARFI values ≥2 m/s (sensitivity=7%, specificity=53.8%; P=0.003).

CONCLUSION

We found that children who were transplanted had two consecutive ARFI values ≥2 m/s during follow-up. ARFI for evaluation of post-Kasai liver fibrosis may assist the long-term assessment of biliary atresia and may even guide treatment decisions.