Liver elasticity measurement before and after biliary drainage in patients with obstructive jaundice: a prospective cohort studya prospective cohort study

Significance of Shear Wave Dispersion Slope Values Before Versus After Biliary Drainage in Patients With Obstructive Jaundice: A Single-Center Prospective Observational Cohort Study

ABSTRACT

The shear wave dispersion (SWD) slope has become available in the clinical practice and is related to tissue viscosity. However, clinical evaluation using SWD was not yet performed for obstructive jaundice. We aimed to evaluate the change of SWD values between before and after biliary drainage in patients with obstructive jaundice. This prospective observational cohort study evaluated 20 patients with obstructive jaundice who underwent biliary drainage. The SWD and liver elasticity values were measured before versus after biliary drainage, comparing between days -5 and 0 (day 0), days 1 and 3 (day 2), and days 6 and 8 (day 7). The mean ± SD values of SWD measured at day 0, day 2, and day 7 were 15.3 ± 2.7, 14.2 ± 3.3, and 13.3 ± 2.4 m/s/kHz, respectively. Dispersion slope values were decreased significantly from day 0 to day 2, from day 2 to day 7, and from day 0 to day 7 ( P < 0.05). Liver elasticity levels and serum hepatobiliary enzymes were additionally decreased significantly over time after biliary drainage. The correlations between SWD and liver elasticity values were strong ( r = 0.91, P < 0.01). In conclusion, t he SWD values decreased significantly over time after biliary drainage concomitant with liver elasticity.

Factors other than fibrosis that increase measured shear wave velocity

Shear wave elastography (SWE) is now becoming an indispensable diagnostic tool in the routine examination of liver diseases. In particular, accuracy is required for shear wave propagation velocity measurement, which is directly related to diagnostic accuracy. It is generally accepted that the liver shear wave propagation velocity reflects the degree of fibrosis, but there are still few reports on other factors that increase the shear wave propagation velocity. In this study, we reviewed such factors in the literature and examined their mechanisms. Current SWE measures propagation velocity based on the assumption that the medium has a homogeneous structure, uniform density, and is purely elastic. Otherwise, the measurement is subject to error. The other (confounding) factors that we routinely experience are primarily: (1) Conditions that appear to increase the viscous component; and (2) Conditions that appear to increase tissue density. Clinically, the former includes acute hepatitis, congested liver, biliary obstruction, etc, and the latter includes diffuse infiltration of malignant cells, various storage diseases, tissue necrosis, etc. In any case, it is important to evaluate SWE in the context of the entire clinical picture.

The impact of elastography with virtual touch quantification of future remnant liver before major hepatectomy

Background

Liver elastography with virtual touch quantification (VTQ) measures the velocity of the shear wave generated by a short-duration acoustic force impulse, with values expressed in units of velocity (m/s). VTQ can evaluate right or left hepatic lobes separately. VTQ might be appropriate for the evaluation of future remnant liver after hepatectomy.

Methods

We analyzed 95 patients underwent liver elastography with VTQ and both future remnant liver and resected side before hepatectomy of more than two sections, except for central bisectionectomy. We divided the patients into a high VTQ group (≥1.52 m/s, n=37, 39%) and a low VTQ group (<1.52 m/s, n=58, 61%) according to the VTQ of future remnant liver. Transient elastography could not be performed in 22 cases due to tumor size. We defined the group with liver stiffness measurement (LSM) ≥7.9 kPa as the high LSM group (n=29, 40%) and those with LSM <7.9 kPa as the low LSM group (n=44, 60%). We investigated the outcome after hepatectomy and the correlations between the VTQ of future remnant liver and other indicators for hepatic fibrosis.

Results

The high VTQ group showed significantly higher postoperative ascites (19% vs. 3%; P=0.01), pathological fibrosis (19% vs. 5%; P=0.03), and rates of patients with postoperative T-bil ≥2.0 mg/dL (70% vs. 40%; P<0.01). The high LSM group showed no significant postoperative outcomes compared to the low LSM group. The high VTQ group showed a higher frequency of male gender (78% vs. 57%; P=0.03), higher indocyanine green retention rate at 15 min (ICGR15) (10.5% vs. 6.3%; P<0.01), hyaluronic acid (100 vs. 67 ng/mL; P=0.02), type IV collagen 7S (7.6 vs. 5.1 ng/mL; P<0.01), Mac-2 binding protein glycan isomer (M2BPGi) (1.19 vs. 1.00; P=0.01), Fibrosis-4 (FIB-4) index (2.25 vs. 1.76; P=0.01), and aspartate aminotransferase to platelet ratio index (APRI) score (0.64 vs. 0.41; P<0.01). We also observed an especially strong positive correlation between the high VTQ and hyaluronic acid or type IV collagen 7S.

Conclusions

Elastography with VTQ for future remnant liver before major hepatectomy is an accurate and useful method as a preoperative evaluation.

How intrahepatic cholestasis affects liver stiffness in patients with chronic hepatitis B: a study of 1197 patients with liver biopsy

OBJECTIVES

To evaluate the impact of intrahepatic cholestasis on liver fibrosis staging using liver stiffness measurements (LSM).

METHODS

Between July 2011 and September 2016, a total of 1197 patients with chronic hepatitis B (CHB) infection were enrolled to collect clinical, biological, 2D shear wave elastography (SWE), and histological (METAVIR scoring system) data. LSM was compared in patients with normal total bilirubin (TB) versus abnormal TB for each group of fibrosis stage, alanine aminotransferase (ALT) levels, and inflammation grade. Logistic regression and ROC analyses were performed to assess the benefit of adding TB and to LSM for fibrosis staging.

RESULTS

Nine hundred and seventy-three patients were analyzed. Within the same fibrosis stage, LSMs showed significantly higher value in patients with abnormal TB than those with normal TB. Increased LSM for abnormal TB was generally found within different sub-groups of patients (≤ F2 or ≥ F3; ALT < 2 × upper limit of normal (ULN) or ALT ≥ 2 × ULN; METAVIR activity grade ≤ 1 or ≥ 2). Patients with abnormal TB level showed higher optimal cutoff values: 10.46 kPa for ≥ F2, 10.94 kPa for ≥ F3, and 15.88 kPa for F4, than those with normal TB (7.62 kPa, 8.26 kPa, and 11.01 kPa, respectively). LSM assessed fibrosis stage (≥ F2, ≥ F3, F4) showed higher false positive rate in patients with abnormal TB level (44.6%, 45.1%, 39.6%) than those with normal TB (20.7%, 17.1%, 14.4%). However, the area under the ROC curve did not change appreciably when adding TB to LSM for fibrosis stage.

CONCLUSION

Intrahepatic cholestasis showed slight effect on LSM in patients with CHB, also leading to overestimation of liver fibrosis stages. But adding TB level to LSM did not improve the overall diagnostic performance of liver fibrosis stage.

KEY POINTS

• Intrahepatic cholestasis showed slight effect on liver stiffness measurements (LSMs) in chronic HBV patients. • Patients with abnormal total bilirubin (TB) level showed higher optimal cutoff values and false positive rate. • When taking into account intrahepatic cholestasis, the diagnostic performance of LSM for liver fibrosis staging in patients with chronic HBV infection will not improve.

Correlation between Liver Elasticity by Ultrasound Elastography and Liver Functional Reserve

No worldwide consensus on the assessment tool for liver functional reserve is currently available. The aim of this study was to evaluate the correlation between liver elasticity of both hepatic lobes and liver functional reserve tests. This prospective observational study comprised 40 patients scheduled for hepatectomy. Liver elasticity was assessed by Virtual Touch Quantification (VTQ). The mean VTQ value for the right and left lobes was defined as the mVTQ. Liver functional reserve was measured with technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin scintigraphy as LHL15 and HH15 and the indocyanine green (ICG) excretion test as ICG-R15 and ICG-K. All examinations were measured after biliary decompression confirmed serum a total bilirubin level ≤2 mg/dL. Mean VTQ values were moderately correlated with LHL15 (r = -0.42, p < 0.01), HH15 (r = 0.48, p < 0.01), ICG-R15 (r = 0.53, p < 0.01) and ICG-K (r = -0.61, p < 0.01) values. In conclusion, the liver elasticity determined by VTQ would be a useful predictor of liver functional reserve in patients scheduled for hepatectomy.

Insight into the metabolic mechanism of scoparone on biomarkers for inhibiting Yanghuang syndrome

Scoparone (6,7-dimethoxycoumarin) is the representative ingredient of Yinchenhao (Artemisia capillaris Thunb.) which is a famous Chinese medicinal herb and shows favorable efficacy for all kinds of liver disease, specifically for the treatment of Yanghuang syndrome (YHS). The precise molecular mechanism concerning the action of scoparone on YHS is yet to be fully elucidated. The aim of the present study was to determine the mechanism of scoparone and evaluate its efficacy on metabolite levels. The differential expression of metabolites responsible for the pharmacological effects of scoparone was characterized and the protection effect of scoparone against this disease. Using multivariate statistical analysis, 33 biomarkers were identified using precise MS/MS and play an important role in the regulation of key metabolic pathways associated with liver disease. In addition, pathological results also showed consistent changes in the YHS model group and after treatment with scoparone, both the metabolic profile and histopathology resembled that of normal level, which suggesting favorable efficacy over the observed time period. The present work indicated that a metabolomics platform provided a new insight into understanding the mechanisms of action of natural medicines such as scoparone.