Recent variceal bleeding: Doppler US hepatic vein waveform in assessment of severity of portal hypertension and vasoactive drug response

Point-of-Care Ultrasound in Gastroenterology and Hepatology

Point-of-care ultrasound (POCUS) is changing the practice of nearly all specialties and is increasingly being incorporated as a bedside tool by more gastroenterologists and hepatologists. POCUS is most often used to answer focused diagnostic questions, supplement the traditional physical examination, and guide performance of invasive bedside procedures. This review describes several common POCUS applications used in gastroenterology and hepatology, as well as some novel applications that warrant further investigation.

Prediction of Esophageal Varices in Viral Hepatitis C Cirrhosis: Performance of Combined Ultrasonography and Clinical Predictors

Objectives

This study is aimed at evaluating the diagnostic performance of clinical predictors and the Doppler ultrasonography in predicting esophageal varices (EV) in patients with hepatitis C-related cirrhosis and exploring the practical predictors of EV.

Methods

We conducted a prospective study from July 2020 to January 2021, enrolling 65 patients with mild hepatitis C-related cirrhosis. We obtained clinical data and performed grayscale and the Doppler ultrasound to explore the predictors of EV. Esophagogastroduodenoscopy (EGD) was performed as the reference test by the gastroenterologist within a week.

Results

The prevalence of EV in the study was 41.5%. Multivariable regression analysis revealed that gender (female, OR = 4.04, p = 0.02), platelet count (<150000 per ml, OR = 3.13, p = 0.09), splenic length (>11 cm, OR = 3.64, p = 0.02), and absent right hepatic vein (RHV) triphasicity (OR = 3.15, p = 0.03) were significant predictors of EV. However, the diagnostic accuracy indices for isolated predictors were not good (AUROC = 0.63-0.66). A combination of these four predictors increases the diagnostic accuracy in predicting the presence of EV (AUROC = 0.80, 95% CI 0.69-0.91). Furthermore, the Doppler assessment of the right hepatic vein waveform showed good reproducibility (κ = 0.76).

Conclusion

Combining clinical and Doppler ultrasound features can be used as a screening test for predicting the presence of EV in patients with hepatitis C-related cirrhosis. The practical predictors identified in this study could serve as an alternative to invasive EGD in EV diagnosis. Further studies are needed to explore the diagnostic accuracy of additional noninvasive predictors, such as elastography, to improve EV screening.

Bibliometric-analysis visualization and review of non-invasive methods for monitoring and managing the portal hypertension

Background

Portal hypertension monitoring is important throughout the natural course of cirrhosis. Hepatic venous pressure gradient (HVPG), regarded as the golden standard, is limited by invasiveness and technical difficulties. Portal hypertension is increasingly being assessed non-invasively, and hematological indices, imaging data, and statistical or computational models are studied to surrogate HVPG. This paper discusses the existing non-invasive methods based on measurement principles and reviews the methodological developments in the last 20 years.

Methods

First, we used VOSviewer to learn the architecture of this field. The publications about the non-invasive assessment of portal hypertension were retrieved from the Web of Science Core Collection (WoSCC). VOSviewer 1.6.17.0 was used to analyze and visualize these publications, including the annual trend, the study hotspots, the significant articles, authors, journals, and organizations in this field. Next, according to the cluster analysis result of the keywords, we further retrieved and classified the related studies to discuss.

Results

A total of 1,088 articles or review articles about our topic were retrieved from WoSCC. From 2000 to 2022, the number of publications is generally growing. “World Journal of Gastroenterology” published the most articles (n = 43), while “Journal of Hepatology” had the highest citations. “Liver fibrosis” published in 2005 was the most influential manuscript. Among the 20,558 cited references of 1,088 retrieved manuscripts, the most cited was a study on liver stiffness measurement from 2007. The highest-yielding country was the United States, followed by China and Italy. “Berzigotti, Annalisa” was the most prolific author and had the most cooperation partners. Four study directions emerged from the keyword clustering: (1) the evaluation based on fibrosis; (2) the evaluation based on hemodynamic factors; (3) the evaluation through elastography; and (4) the evaluation of variceal bleeding.

Conclusion

The non-invasive assessment of portal hypertension is mainly based on two principles: fibrosis and hemodynamics. Liver fibrosis is the major initiator of cirrhotic PH, while hemodynamic factors reflect secondary alteration of splanchnic blood flow. Blood tests, US (including DUS and CEUS), CT, and magnetic resonance imaging (MRI) support the non-invasive assessment of PH by providing both hemodynamic and fibrotic information. Elastography, mainly USE, is the most important method of PH monitoring.

Network Meta-Analysis: Noninvasive Imaging Modalities for Identifying Clinically Significant Portal Hypertension

BACKGROUND

Although measurement of the hepatic venous pressure gradient (HVPG) is the current reference standard for obtaining portal venous pressures, several noninvasive imaging-based modalities have been proposed as alternatives.

AIMS

We performed a systematic review and meta-analysis to compare the diagnostic accuracy of noninvasive imaging approaches for identifying clinically significant portal hypertension (CSPH).

METHODS

Two independent reviewers conducted a literature search of PubMed, SCOPUS, and the Cochrane Library from inception until January 5, 2021. The following imaging modalities were compared to HVPG: computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance elastography, ultrasound, transient elastography (TE), shear wave elastography (SWE), acoustic radiation force impulse (ARFI) imaging, contrast-enhanced ultrasound (CEUS), and subharmonic-aided pressure estimation (SHAPE). Sensitivity, specificity, diagnostic odds ratio (DOR), and area under the curve (AUC) for summary receiver operating characteristic were calculated using both frequentist random effects and Bayesian network meta-analytic approaches.

RESULTS

We analyzed 45 studies of 5678 patients. A broad overlapping confidence interval (CI) of DOR was observed among different imaging modalities: ARFI (30.5; 95% CI 12.7-73.3), CEUS and SHAPE (21.1; 95% CI 6.4-69.8), TE of liver stiffness (21.1; 95% CI 13.3-33.5), CT and MRI (13.7; 95% CI 7.40-25.4), SWE of liver stiffness (10.5; 95% CI 5.2-21.1), and ultrasound (9.5; 95% CI 4.9-18.4). The AUC of all imaging methods exceeded 0.8, indicating very good performance. At a cutoff of 80% specificity, TE, CEUS, and SHAPE exceeded 80% sensitivity.

CONCLUSION

Overall, noninvasive imaging modalities perform well for identifying CSPH. Clinicians should consider these noninvasive and cost-efficient tests when diagnosing CSPH.

The severity of portal hypertension by a non-invasive assessment: acoustic structure quantification analysis of liver parenchyma

Background

Acoustic structure quantification (ASQ) has been applied to evaluate liver histologic changes by analyzing the speckle pattern seen on B-mode ultrasound. We aimed to assess the severity of portal hypertension (PHT) through hepatic ultrasonography.

Methods

Sixty patients diagnosed with PHT and underwent surgical treatment with portosystemic shunts were enrolled. Portal pressure (PP) was measured intraoperatively. Patients were divided into subgroups according to the severity of gastroesophageal varices and Child–Pugh class. Three difference ratio (C_m²) values on ASQ histogram mode were analyzed for their relationships with PP, degree of gastroesophageal varices and Child–Pugh liver function. Thirty healthy volunteers matched with the patients for gender and age were enrolled as controls. Comparisons among groups and correlation of the parameters with PP were analyzed. Area under the receive operating characteristic curve was used to evaluate the predicting value of ASQ parameters.

Results

In the patients, the ASQ parameters peak C_m² (C_m²_max), mean C_m² (C_m²_mean) and the highest occurred C_m² value of the obtained red curve (R_maxC_m²) were all greatly increased (P < 0.0001, P < 0.0001, P = 0.027). Multiple comparisons indicated that, regardless of Child–Pugh class and degree of gastroesophageal varices, the patients had significantly increased C_m²_max and C_m²_mean compared with the controls (all P < 0.0001). No differences among subgroups were observed. C_m²_max was significantly statistically correlated with PP (r = 0.3505, P < 0.01), degree of varices (r = 0.4998, P < 0.0001). Youden’s index for C_m²_max with a cut-off value of 140.3 for predicting the presence of PHT, gastroesophageal varices and liver function equal to or worse than Child–Pugh class B were 0.8, 0.91 and 0.84, respectively.

Conclusions

ASQ analysis of ultrasonographic images may have a role in the evaluation of the severity of PHT by detecting liver histologic changes in the speckle pattern caused by cirrhosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00817-2.

Application of ultrasound for the diagnosis of cirrhosis/portal hypertension

With advances in technologic approaches in patients with cirrhosis, including the improvement of management, a simple, one-step approach for advanced fibrotic state of the liver is clinically useful. Although refining the diagnosis of cirrhosis to reflect disease heterogeneity is essential, current diagnostic tests have not kept pace with the progression of this new paradigm. There are unmet needs in primary care centers with respect to patients with cirrhosis. Liver biopsy and measurement of hepatic venous pressure gradient in patients with cirrhosis are the gold standards for the estimation of hepatic fibrosis, and they have diagnostic and prognostic value. However, both approaches are invasive and cannot be used repeatedly in clinical practice. Ultrasonography (US) is safe, easy to perform, inexpensive, and yields numerical and accurate results. Conventionally, the size of the liver and spleen, bluntness of the liver edge, nodularity of the liver surface, and coarseness of the liver parenchyma have been known as useful parameters for hepatic fibrosis or portal hypertension (PHT) in chronic liver disease. Additionally, some functional US indices including Doppler and CEUS-based examination have been suggested as promising markers for diagnosing cirrhosis and PHT. Identification of the reproducibility and long-term prognostic value through further investigations can demonstrate the clinical usefulness of functional US indices, which are characterized as quantitative parameters for hepatic fibrosis and PHT.

Hepatic function predictive value of hepatic venous waveform versus portal vein velocity in liver cirrhosis

Background:

This study assessed the hepatic vein waveform (HVW) and mean maximum portal vein velocity (MM-PVV) on Doppler ultrasound in patients with liver cirrhosis (LC) and compared it with that of age and sex-matched controls. It correlated the degree of HVW abnormality and MM-PVV changes with liver function based on Child-Turcotte-Pugh (CTP) to determine which was more predictive of CTP.

Methods:

Sixty patients with LC and 60 healthy controls were consecutively recruited into this study. Each patient was classed based on the CTP system after relevant tests. Doppler evaluation of the hepatic vein (HV) and MM-PVV were performed. HVW obtained was classified either into triphasic, biphasic, or monophasic.

Results:

Sixty cirrhotic and 60 age-matched control subjects aged 19–69 and 18–69 years, respectively, completed this study. All control subjects had a normal HVW pattern while 46 (76.7%) cirrhotic subjects had abnormal HVW (P < 0.001). The MM-PVV was significantly lower in cirrhotic subjects than in controls; 22.8 cm/s versus 33.6 cm/s (P < 0.001). The degree of HVW abnormality among cirrhotics showed a significant positive correlation with CTP (r = 0.283, P = 0.029). MM-PVV on the other hand showed no correlation with CTP class (r = −0.124; P = 0.346). Linear regression showed that HVW was a significant predictor of hepatic dysfunction based on CTP.

Conclusion:

Changes in the waveform pattern of the HVs are a good predictor of the derangement of hepatic function in patients with LC than changes in PVV. HVW pattern could therefore serve as an adjunct to CTP class in hepatic function assessment.

Accurate ultrasonography-based portal pressure assessment in patients with hepatocellular carcinoma

BACKGROUND

Portal pressure is of great significance in the treatment of hepatocellular carcinoma (HCC), but direct measurement is complicated and costly; thus, non-invasive measurement methods are urgently needed.

AIM

To investigate whether ultrasonography (US)-based portal pressure assessment could replace invasive transjugular measurement.

METHODS

A cohort of 102 patients with HCC was selected (mean age: 54 ± 13 years, male/female: 65/37). Pre-operative US parameters were assessed by two independent investigators, and multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for the portal pressure gradient (PPG). The estimated PPG predictors were compared with the transjugular PPG measurements. Validation was conducted on another cohort of 20 non-surgical patients.

RESULTS

The mean PPG was 17.32 ± 1.97 mmHg. Univariate analysis identified the association of the following four parameters with PPG: Spleen volume, portal vein diameter, portal vein velocity (PVV), and portal blood flow (PBF). Multiple linear regression analysis was performed, and the predictive formula using the PVV and PBF was as follows: PPG score = 19.336 - 0.312 × PVV (cm/s) + 0.001 × PBF (mL/min). The PPG score was confirmed to have good accuracy with an area under the curve (AUC) of 0.75 (0.68-0.81) in training patients. The formula was also accurate in the validation patients with an AUC of 0.820 (0.53-0.83).

CONCLUSION

The formula based on ultrasonographic Doppler flow parameters shows a significant correlation with invasive PPG and, if further confirmed by prospective validation, may replace the invasive transjugular assessment.

Portal hypertension evolving from sickled hepatopathy: Could hepatic venous Doppler ultrasound be beneficial in its evaluation?

PURPOSE

Sickle cell intrahepatic cholestasis involves sickling within hepatic sinusoids leading to vascular stasis and localized hypoxia resulting in ballooning of the hepatocytes causing a direct back pressure effect with resultant intracanalicular cholestasis. Vascular stasis may ultimately lead to portal hypertension. We proposed to document findings suggestive of portal hypertension evolving from hepatopathy in steady-state sickle cell disease (SCD) patients using hepatic venous Doppler ultrasound.

METHODS

This is a prospective case series of 6 SCD subjects in steady-state (median age, 30 years; range, 19-43), comprising of 3 males and 3 females, who underwent a routine Doppler ultrasound evaluation of their hepatic veins and were discovered to have an abnormal biphasic waveform pattern. Venous blood was obtained from all subjects to evaluate for P-selectin, homocysteine, foetal haemoglobin, haematocrit levels, white cell and platelet counts. Doppler ultrasound was also carried out on all subjects to evaluate for the hepatic waveform, right renal artery RI and PI along with the hepatic artery velocities.

RESULTS

All the 6 subjects had reduced haematocrit (median value of 21.5%; range, 18-25%) and some degree of renal dysfunction (plasma cystatin-C ranged from 1.6 to 12.2 mg/L). Elevated white cell count, hyperhomocysteinemia, reduced SpO₂(<94.0%) and reduced estimated GFR (eGFR < 90 ml/min) was also noted in 4 subjects (66.7%). Similarly, 4 subjects (66.7%) had elevated RI in the right kidneys while 3 subjects (50.0%) had elevated PI in the right kidney.

CONCLUSION

Doppler ultrasound Hepatic vein waveform analysis may be a useful examination in the evaluation of patients with SCD as it may elicit feature of portal hypertension. Further studies are suggested to confirm this in a larger population of SCD patients using the gold standard.

Evaluation of portal hypertension in the cirrhotic patient: hepatic vein pressure gradient and beyond

Portal hypertension (PH) is a major complication of liver cirrhosis, as it predisposes to the development of serious clinical manifestations such as ascites, hepatic encephalopathy and variceal bleeding. Till now, the measurement of hepatic vein pressure gradient (HVPG) is the gold standard method to ascertain the presence and significance of PH, as many studies have shown its correlation with the appearance of varices and the possibility of variceal bleeding. However, the invasiveness of this procedure makes it difficult to be used in daily clinical practice. Several noninvasive methods with adequate capability of evaluating liver fibrosis, including elastographic techniques, are currently used as alternatives to HVPG in order to assess the presence and the severity of PH. The aim of this paper is to express an overview of the literature about the actual role of HVPG and all available noninvasive tests on the prediction of development of PH complications, to highlight their advantages and their potential limitations, and to provide the latest trends on clinical practice.

Hemodynamic measurements with an abdominal 4D flow MRI sequence with spiral sampling and compressed sensing in patients with chronic liver disease

BACKGROUND

The test-retest/interobserver repeatability and diagnostic value of 4D flow MRI in liver disease is underreported.

PURPOSE

To determine the reproducibility/repeatability of flow quantification in abdominal vessels using a spiral 4D flow MRI sequence; to assess the value of 4D flow parameters in diagnosing cirrhosis and degree of portal hypertension.

STUDY TYPE

Prospective.

SUBJECTS

Fifty-two patients with chronic liver disease.

FIELD STRENGTH/SEQUENCE

1.5T/spiral 4D flow acquired in one breath-hold.

ASSESSMENT

Thirteen abdominal vessels were identified and segmented by two independent observers to measure maximum and time-averaged through-plane velocity, net flow, and vessel cross-section area. Interobserver agreement and test-retest repeatability were evaluated in 15 and 4 cases, respectively. Prediction of the presence and severity of cirrhosis and portal hypertension was assessed using 4D flow parameters.

STATISTICAL TESTS

Cohen's kappa coefficient, coefficient of variation (CV), Bland-Altman, Mann-Whitney tests, logistic regression.

RESULTS

For all vessels combined, measurements showed acceptable agreement between observers, with Cohen's kappa = 0.70 (P < 0.001), CV < 21%, Bland-Altman bias <5%, but high limits of agreement ([-75%,75%]). Test-retest repeatability was excellent in large vessels (CV = 1-15%, bias = 1-25%, Bland-Altman limits of agreement [BALA] = [4%,150%]), and poor in small vessels (CV = 7-130%, bias = 10-200%, BALA = [8%,190%]). Average velocity in the right hepatic vein and average area of the splenic vein were higher in cirrhosis (P = 0.027/0.0039). Flow in the middle hepatic vein strongly correlated with Child-Pugh score (ρ = 0.84, P = 0.0238), while flow in the splenic vein (ρ = 0.43, P = 0.032), time-average (ρ = 0.46, P = 0.02) and peak velocity in the superior mesenteric vein (ρ = 0.45, P = 0.032), and peak velocity in the infrarenal IVC (ρ = 0.39, P = 0.032) positively correlated with an imaging-based portal hypertension score. Average area of the splenic vein predicted cirrhosis (P = 0.019; area under the curve AUC [95% confidence interval, CI] = 0.87 [0.71,1.00]) and clinically significant portal hypertension (P = 0.042; AUC [95% CI] = 0.78 [0.57-0.99]).

DATA CONCLUSION

Spiral 4D flow allows comprehensive assessment of abdominal vessels in one breath-hold, with substantial interobserver reproducibility, but variable test-retest repeatability. 4D flow may potentially reflect vascular changes due to cirrhosis and portal hypertension.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:994-1005.

Point Shear Wave Elastography of the Spleen: Its Role in Patients with Portal Hypertension

The goals of the study described here were to evaluate the feasibility and reproducibility of measuring spleen stiffness (SS) using point shear wave elastography in a series of cirrhotic patients and to investigate whether SS, liver stiffness (LS) and other non-invasive parameters are correlated with the presence of esophagogastric varices (EVs). Fifty-four cirrhotic patients with low-grade EVs or without EVs at esophago-gastro-duodenoscopy were enrolled. They underwent abdominal ultrasound and Doppler ultrasound of hepatic vessels simultaneously with p-SWE of the liver and spleen. In 42 patients, the accuracy of LS and SS, as well as of platelet count and spleen longitudinal diameter, in predicting the presence of EVs was evaluated. The technical success was 90.74% for LS (49/54 patients) and 77.78% for SS (42/54 patients). Inter-observer agreement for SS measurement was high. Both LS and SS correlated with esophago-gastro-duodenoscopy: LS had the highest accuracy in predicting the presence of EVs (area under the receiver operating characteristic curve [AUROC] = 0.913); SS had the lowest accuracy (AUROC = 0.675); platelet count and spleen diameter had intermediate accuracy (AUROC = 0.731 and 0.729, respectively). SS did not have an advantage over LS in predicting low-grade EVs and cannot be proposed as a useful tool in the diagnostic process of cirrhotic patients who require screening esophago-gastro-duodenoscopy.

Hepatic vein transit time of second-generation ultrasound contrast agent: new tool in the assessment of portal hypertension

PURPOSE

It has been demonstrated that Doppler waveform of the hepatic vein (normally triphasic) is transformed into a biphasic or monophasic waveform in cirrhotic patients. The compressive mechanism of liver tissue has been considered up till now the cause of this change. Moreover, cirrhotics show, after USCA injection, a much earlier HVTT due to intrahepatic shunts. Our aim was to prospectively evaluate the correlation between Doppler pattern of hepatic vein and HVTT of a second-generation USCA; we also correlated HVTT with the most common indexes of portal hypertension.

METHODS

We enrolled 38 participants: 33 cirrhotics and 5 healthy controls. Doppler shift signals were obtained from the right hepatic vein. To characterize the hepatic vein pattern, we used the hepatic vein waveform index (HVWI). This index becomes >1 with the appearance of the triphasic waveform. We recorded a clip from 20 s before to 2 min after a peripheral intravenous bolus injection of 2.4 ml of USCA (sulfur hexafluoride).The time employed by USCA to cross the liver from the hepatic artery and portal vein to the hepatic vein was defined as HA-HVTT and PV-HVTT, respectively.

RESULTS

Cirrhotics with low HVWI showed an earlier transit time; participants with higher HVWI had a longer transit time (p < 0.001). HVTT was earlier as MELD, Child-Pugh score and spleen diameter increased. Patients with ascites and varices of large size had significantly shorter transit times.

CONCLUSIONS

Abnormal hepatic vein Doppler waveform in cirrhotic patients could be due to intrahepatic shunts. HVTT could be useful in the non-invasive evaluation of portal hypertension.

Doppler waveform study as indicator of change of portal pressure after administration of octreotide

Objective:

To estimate the effect of portal pressure lowering drug ‘octreotide’, by observing the Doppler waveform before and after the administration of intravenous bolus of octreotide and thus to assess indirectly its efficacy to lower the portal pressure.

Methods:

This quassi experimental study was carried out in Medical Department in collaboration with Radiology Department of Jinnah Postgraduate Medical Center Karachi Pakistan from September 10, 2015 to February 5, 2016. Cases were selected from patients admitted in Medical Wards and those attending Medical OPD. Diagnosis of cirrhosis was confirmed by Clinical Examination and Lab & Imaging investigation in Medical Department. Doppler waveform study was done by experienced radiologist in Radiology Department before and after administration of octreotide. Doppler signals were obtained from the right hepatic vein. Waveform tracings were recorded for five seconds and categorized as ‘monophasic’, ‘biphasic’ and ‘triphasic’. Waveform changes from one waveform to other were noted and analyzed.

Results:

Significant change i.e. from ‘monophasic’ to ‘biphasic’ or ‘biphasic’ to ‘triphasic’ was seen in 56% cases while ‘monophasic’ to ‘triphasic’ was seen in 20% cases. No change was seen in 24% cases. Improvement in waveform reflects lowering of portal vein pressure.

Conclusion:

Non invasive Hepatic vein Doppler waveform study showed improvement in Doppler waveform after administration of octreotide in 76% cases. Doppler waveform study has the potential of becoming non invasive ‘follow up tool’ of choice for assessing portal pressure in patients having variceal bleed due to portal hypertension.

Hepatic Venous Waveform, Splenoportal and Damping Index in Liver Cirrhosis: Correlation with Child Pugh's Score and Oesophageal Varices

INTRODUCTION

Clinical assessment of chronic liver disease is done by Modified Child Pugh's and Model for end-stage liver disease scoring system. Measurement of hepatic venous pressure gradient (HVPG) and Upper GI Endoscopy are considered the gold standards for measurement of portal hypertension in cirrhotics. There is a need for non-invasive evaluation of portal hypertension. Ultrasonography with colour and spectral Doppler evaluation may be an effective, rapid and inexpensive alternative.

AIM

To evaluate hepatic venous waveform, damping index, splenoportal index in patients of cirrhosis on Colour Doppler ultrasound, also predict severity of portal hypertension and presence of oesophageal varices.

MATERIALS AND METHODS

Thirty patients of chronic liver disease were included in the study. Ultrasound and colour Doppler was done to look hepatic venous waveform pattern, Damping Index (DI), and Splenoportal Index (SPI). Contrast-enhanced Computed Tomography scan (CT) was done if renal function tests were normal, else endoscopy when the renal function tests were deranged to look for oesophageal varices.

RESULTS

Twenty two (73.3%) patients had monophasic waveform. Biphasic and triphasic waveforms were seen in 4 (13.3%) cases. Twenty two patients (73.3%) had monophasic waveforms and majority of them were in class C. This distribution of hepatic vein waveform was statistically significantly with the Child Pugh's class (p<0.05). Twenty patients (66.7%) had value of Damping index more than >0.6 where majority of patients (18) belonged to class C and 2 in class B. There was a positive correlation between Child Pugh's total score and Damping index (r=0.614; p<0.05). There was weak positive correlation between splenoportal index and Child Pugh's score (r=0.269; p=0.15).

CONCLUSION

Change in triphasic to monophasic waveform and DI >0.6 suggests severe liver dysfunction and is associated with severe portal hypertension. Hepatic venous waveform pressure changes, DI and SPI have no value in predicting presence of oesophageal varices.

Personalized management of cirrhosis by non-invasive tests of liver fibrosis

Owing to the high prevalence of various chronic liver diseases, cirrhosis is one of the leading causes of morbidity and mortality worldwide. In recent years, the development of non-invasive tests of fibrosis allows accurate diagnosis of cirrhosis and reduces the need for liver biopsy. In this review, we discuss the application of these non-invasive tests beyond the diagnosis of cirrhosis. In particular, their role in the selection of patients for hepatocellular carcinoma surveillance and varices screening is highlighted.

Usefulness of B-mode and doppler sonography for the diagnosis of severe acute viral hepatitis A

BACKGROUND

To investigate B-mode and Doppler ultrasonography (US) features correlating with laboratory findings for the diagnosis of severe acute hepatitis (SAH) in patients with hepatitis A virus infection.

METHODS

Thirty-nine consecutive serologically proven patients were enrolled. Decreased parenchymal echotexture, periportal tracking, gallbladder wall change, and splenomegaly were assessed on B-mode images. Blood flow velocities were measured in the main portal (V(PORTAL)) and in the hepatic veins, and the hepatic venous pulsatility index was calculated. SAH was defined as high model for end-stage liver disease (MELD) score ≥ 15 with or without coagulopathy. The relationship between US features and laboratory findings was assessed, and SAH diagnosis was evaluated.

RESULTS

Serum alanine transaminase and prothrombin time were significantly different depending on the presence of gallbladder wall change and splenomegaly (p < 0.05). V(PORTAL) was inversely correlated with MELD score (r = -0.485) and several laboratory markers. The hepatic venous waveform and hepatic venous pulsatility index were significantly correlated with MELD score. For the diagnosis of SAH, the area under the receiver operating characteristic curve of V(PORTAL) was 0.798. It reached 0.869 in the patients with typical GB change.

CONCLUSIONS

Both B-mode and Doppler US correlated well with several laboratory variables and may be helpful to diagnose SAH in patients with hepatitis A virus infection.

Severe portal hypertension in cirrhosis: evaluation of perfusion parameters with contrast-enhanced ultrasonography

OBJECTIVE

To investigate the role of contrast-enhanced ultrasonography (CEUS) and Doppler ultrasonography (DUS) in the diagnosis of severe portal hypertension (PH) in patients with liver cirrhosis (LC).

METHODS

Patients with PH scheduled to receive hepatic venous pressure gradient (HVPG) measurement were recruited for this study. Hepatic DUS and CEUS were performed successively. Several Doppler and CEUS parameters were explored for correlation with HVPG values and their association with severe PH (≥ 12 mmHg of HVPG). Comparison of the parameters between the severe and non-severe PH groups and their correlation with HVPG values was evaluated. A receiver operating characteristic (ROC) curve analysis was also performed to investigate the performance in order to diagnose severe PH.

RESULTS

Fifty-three consecutive patients were enrolled in this study. Among them, 43 patients did not have significant ascites. Compared with the non-severe PH group, portal venous velocity and intrahepatic transit time (ITT) were significantly reduced in the severe PH group (all p<0.05). Difference between inspiratory and expiratory hepatic venous damping indices (ΔHVDI), hepatic venous arrival time (HVAT) and ITT moderately correlated with HVPG (r = -0.358, -0.338, and -0.613, respectively). Areas under the curves for severe PH were 0.94 of ITT and 0.72 of HVAT, respectively (all p<0.05). ITT under 6 seconds indicated severe PH with a sensitivity of 92% and a specificity of 89%.

CONCLUSIONS

Hepatic CEUS may be more useful in estimating the HVPG value and determining the presence of severe PH compared to DUS, and ITT was the most accurate parameter to diagnose severe PH.

The accuracy of ultrasonography for the evaluation of portal hypertension in patients with cirrhosis: a systematic review

Objective

Studies have presented conflicting results regarding the accuracy of ultrasonography (US) for diagnosing portal hypertension (PH). We sought to identify evidence in the literature regarding the accuracy of US for assessing PH in patients with liver cirrhosis.

Materials and Methods

We conducted a systematic review by searching databases, including MEDLINE, EMBASE, and the Cochrane Library, for relevant studies.

Results

A total of 14 studies met our inclusion criteria. The US indices were obtained in the portal vein (n = 9), hepatic artery (n = 6), hepatic vein (HV) (n = 4) and other vessels. Using hepatic venous pressure gradient (HVPG) as the reference, the sensitivity (Se) and specificity (Sp) of the portal venous indices were 69-88% and 67-75%, respectively. The correlation coefficients between HVPG and the portal venous indices were approximately 0.296-0.8. No studies assess the Se and Sp of the hepatic arterial indices. The correlation between HVPG and the hepatic arterial indices ranged from 0.01 to 0.83. The Se and Sp of the hepatic venous indices were 75.9-77.8% and 81.8-100%, respectively. In particular, the Se and Sp of HV arrival time for clinically significant PH were 92.7% and 86.7%, respectively. A statistically significant correlation between HVPG and the hepatic venous indices was observed (0.545-0.649).

Conclusion

Some US indices, such as HV, exhibited an increased accuracy for diagnosing PH. These indices may be useful in clinical practice for the detection of significant PH.

Value of shear wave elastography for predicting hepatocellular carcinoma and esophagogastric varices in patients with chronic liver disease

PURPOSE

To assess the value of shear wave elastography (SWE) for predicting the presence of hepatocellular carcinoma (HCC) and esophagogastric varices (EGV) in patients with chronic liver disease.

METHODS

Liver tissue stiffness, as well as various other parameters potentially associated with HCC and portal hypertension, was measured by SWE in 273 patients with chronic liver disease. Among these patients, HCC was present in 89 and absent in 184, and EGV were present in 16 and absent in 257. The diagnostic performance of liver tissue stiffness and other clinical parameters in predicting the presence of HCC and EGV was evaluated using receiver operating characteristic (ROC) curves and the area under the ROC curve (AUROC).

RESULTS

With regard to HCC, liver tissue stiffness was significantly higher in patients with HCC (18.65 ± 10.78 kPa) than in those without HCC (10.64 ± 8.04 kPa; P < 0.0001). Significant differences in patient age (P < 0.0001), albumin (P < 0.0001), platelet count (P < 0.0001), AFP (P < 0.0001), and DCP (P < 0.0001) were also observed between patients with and without HCC. Liver tissue stiffness showed the largest AUROC (0.791). With regard to EGV, liver tissue stiffness was significantly higher in patients with EGV (22.65 ± 10.19 kPa) than in those without EGV (12.67 ± 9.45 kPa; P < 0.0001). Significant differences in albumin (P < 0.0001) and platelet count (P < 0.0001) were also observed between patients with and without EGV.

CONCLUSIONS

Liver tissue stiffness measured by SWE is an independent factor for predicting the presence of HCC and EGV in patients with chronic liver disease.

Effects of candesartan and propranolol combination therapy versus propranolol monotherapy in reducing portal hypertension

BACKGROUND/AIMS

Angiotensin receptor blockers (ARBs) inhibit activated hepatic stellate cell contraction and are thought to reduce the dynamic portion of intrahepatic resistance. This study compared the effects of combined treatment using the ARB candesartan and propranolol versus propranolol monotherapy on portal pressure in patients with cirrhosis in a prospective, randomized controlled trial.

METHODS

Between January 2008 and July 2009, 53 cirrhotic patients with clinically significant portal hypertension were randomized to receive either candesartan and propranolol combination therapy (26 patients) or propranolol monotherapy (27 patients). Before and 3 months after the administration of the planned medication, the hepatic venous pressure gradient (HVPG) was assessed in both groups. The dose of propranolol was subsequently increased from 20 mg bid until the target heart rate was reached, and the candesartan dose was fixed at 8 mg qd. The primary endpoint was the HVPG response rate; patients with an HVPG reduction of >20% of the baseline value or to <12 mmHg were defined as responders.

RESULTS

The mean portal pressure declined significantly in both groups, from 16 mmHg (range, 12-28 mmHg) to 13.5 mmHg (range, 6-20 mmHg) in the combination group (P<0.05), and from 17 mmHg (range, 12-27 mmHg) to 14 mmHg (range, 7-25 mmHg) in the propranolol monotherapy group (P<0.05). However, the medication-induced pressure reduction did not differ significantly between the two groups [3.5 mmHg (range, -3-11 mmHg) vs. 3 mmHg (range, -8-10 mmHg), P = 0.674]. The response rate (55.6% vs. 61.5%, P = 0.435) and the reductions in mean blood pressure or heart rate also did not differ significantly between the combination and monotherapy groups.

CONCLUSIONS

The addition of candesartan (an ARB) to propranolol confers no benefit relative to classical propranolol monotherapy for the treatment of portal hypertension, and is thus not recommended.

Clinically severe portal hypertension: role of multi-detector row CT features in diagnosis

BACKGROUND AND AIM

To explore the CT signs which permit estimation of clinically severe portal hypertension (PH) [≥ 12 of hepatic vein pressure gradient (HVPG)].

METHODS

One-hundred and seven consecutive patients who underwent HVPG measurement in the PH group and 52 controls were included. The diameters of main portal vein (øMPV), superior mesenteric vein (øSMV), splenic vein (øSV), and left gastric vein, øMPV/øSV, øSMV/øSV, as well as estimated spleen volumes were evaluated on the CT scan. The grade of varix and ascites were also evaluated semi-quantitatively. We explored the statistically significant CT features related to severe PH and performed a logistic regression analysis for an estimation model for severe PH.

RESULTS

øMPV/øSV and øSMV/øSV tended to gradually increase as the PH became severer, and the difference between severe and not severe groups was statistically significant (p = 0.015 and 0.038, respectively). According to the regression analysis, øSMV/øSV and the grade of esophageal varix and ascites were finally included as related variables for predicting severe PH. The odds ratio (OR) of øSMV/øSV was 4.596, and large esophageal varix (OR 4.135) and mild (OR 3.051) and large amount of ascites (OR 21.781) were statistically significantly related to severe PH.

CONCLUSION

Changing diameters of portal system, the grades of esophageal varices and ascites on multi-detector row computed tomography might be indicative features for clinically severe PH.

Shear-wave elastography: a noninvasive tool for monitoring changing hepatic venous pressure gradients in patients with cirrhosis

PURPOSE

To investigate whether liver stiffness ( LS liver stiffness ) and change in LS liver stiffness measurements ( ΔLS change in LS ) at shear-wave elastography ( SWE shear-wave elastography ) correlates with the hepatic venous pressure gradient ( HVPG hepatic venous pressure gradient ) and to assess the feasibility of using SWE shear-wave elastography to estimate the change in HVPG hepatic venous pressure gradient ( ΔHVPG change in HVPG ) in patients with portal hypertension.

MATERIALS AND METHODS

Institutional review board approval was obtained, with waiver of informed consent. Between September 2010 and October 2012, 97 consecutive patients who were given a diagnosis of portal hypertension on the basis of HVPG hepatic venous pressure gradient measurement were included. Among these patients, 23 who underwent follow-up HVPG hepatic venous pressure gradient measurement to evaluate response to treatment were included in the follow-up group. The correlation between HVPG hepatic venous pressure gradient and LS liver stiffness was analyzed by using the Pearson correlation test. In the follow-up group, whether ΔHVPG change in HVPG was correlated with ΔLS change in LS was also evaluated. Thereafter, the areas under the receiver operating characteristic curves ( AUC area under the ROC curve s) were calculated to determine the diagnostic performances of ΔLS change in LS and the second LS liver stiffness measurement after medical treatment and to compare their performances in association with clinical improvement and aggravation of portal hypertension.

RESULTS

LS liver stiffness was moderately correlated with HVPG hepatic venous pressure gradient (r = 0.593) in the single-measurement group. There was also a strong correlation between ΔLS change in LS and ΔHVPG change in HVPG (r = 0.863). At comparison of the second LS liver stiffness measurement, ΔLS change in LS showed no significant difference in AUC area under the ROC curve in patients with improvement (0.627 vs 0.794, P = .201) but showed higher AUC area under the ROC curve in association with aggravation of portal hypertension (0.925 vs 0.611, P = .026).

CONCLUSION

Estimating ΔHVPG change in HVPG by using SWE shear-wave elastography may be useful in patients with cirrhosis and portal hypertension.

Biomarkers of liver fibrosis

Liver fibrosis is the final common pathway for almost all causes of chronic liver injury. Liver fibrosis is now known to be a dynamic process having significant potential for resolution. Therefore, fibrosis prediction is an essential part of the assessment and management of patients with chronic liver disease. As such, there is strong demand for reliable liver biomarkers that provide insight into disease etiology, diagnosis, therapy, and prognosis in lieu of more invasive approaches such as liver biopsy. Current diagnostic strategies range from use of serum biomarkers to more advanced imaging techniques including transient elastography and magnetic resonance imaging. In addition to these modalities, there are other approaches including the use of novel, but yet to be validated, biomarkers. In this chapter, we discuss the biomarkers of liver fibrosis including the use of invasive and noninvasive biomarkers and disease-specific biomarkers in various chronic liver diseases.

Invasive and non-invasive techniques for detecting portal hypertension and predicting variceal bleeding in cirrhosis: a review

Portal hypertension is a severe syndrome that may derive from pre-sinusoidal, sinusoidal, and post-sinusoidal causes. As a consequence, several complications (i.e. ascites, oesophageal varices) may develop. In sinusoidal portal hypertension, hepatic venous pressure gradient (HVPG) is a reliable method for defining the grade of portal pressure, establishing the effectiveness of the treatment, and predicting the occurrence of complications; however, some questions exist regarding its ability to discriminate bleeding from non-bleeding varices in cirrhotic patients. Other imaging techniques (transient elastography, endoscopy, endosonography, and duplex Doppler sonography) for assessing causes and complications of portal hypertensive syndrome are available and may be valuable for the management of these patients. In this review, we evaluate invasive and non-invasive techniques currently employed to obtain a clinical prediction of deadly complications, such as variceal bleeding in patients affected by sinusoidal portal hypertension, in order to create a diagnostic algorithm to manage them. Again, HVPG appears to be the reference standard to evaluate portal hypertension and monitor the response to treatment, but its ability to predict several complications and support management decisions might be further improved through the diagnostic combination with other imaging techniques.

Non-invasive diagnosis of hepatitis B virus-related cirrhosis

Chronic hepatitis B (CHB) infection is a major public health problem associated with significant morbidity and mortality worldwide. Twenty-three percent of patients with CHB progress naturally to liver cirrhosis, which was earlier thought to be irreversible. However, it is now known that cirrhosis can in fact be reversed by treatment with oral anti-nucleotide drugs. Thus, early and accurate diagnosis of cirrhosis is important to allow an appropriate treatment strategy to be chosen and to predict the prognosis of patients with CHB. Liver biopsy is the reference standard for assessment of liver fibrosis. However, the method is invasive, and is associated with pain and complications that can be fatal. In addition, intra- and inter-observer variability compromises the accuracy of liver biopsy data. Only small tissue samples are obtained and fibrosis is heterogeneous in such samples. This confounds the two types of observer variability mentioned above. Such limitations have encouraged development of non-invasive methods for assessment of fibrosis. These include measurements of serum biomarkers of fibrosis; and assessment of liver stiffness via transient elastography, acoustic radiation force impulse imaging, real-time elastography, or magnetic resonance elastography. Although significant advances have been made, most work to date has addressed the diagnostic utility of these techniques in the context of cirrhosis caused by chronic hepatitis C infection. In the present review, we examine the advantages afforded by use of non-invasive methods to diagnose cirrhosis in patients with CHB infections and the utility of such methods in clinical practice.

Ultrasonographic scoring system score versus liver stiffness measurement in prediction of cirrhosis

BACKGROUND/AIMS

We compared the cirrhosis-prediction accuracy of an ultrasonographic scoring system (USSS) combining six representative sonographic indices with that of liver stiffness measurement (LSM) by transient elastography, and prospectively investigated the correlation between the USSS score and LSM in predicting cirrhosis.

METHODS

Two hundred and thirty patients with chronic liver diseases (187 men, 43 women; age, 50.4±9.5 y, mean±SD) were enrolled in this prospective study. The USSS produces a combined score for nodularity of the liver surface and edge, parenchyma echogenicity, presence of right-lobe atrophy, spleen size, splenic vein diameter, and abnormality of the hepatic vein waveform. The correlations of the USSS score and LSM with that of a pathological liver biopsy (METAVIR scoring system: F0-F4) were evaluated.

RESULTS

The mean USSS score and LSM were 7.2 and 38.0 kPa, respectively, in patients with histologically overt cirrhosis (F4, P=0.017) and 4.3 and 22.1 kPa in patients with fibrotic change without overt cirrhosis (F0-F3) (P=0.025). The areas under the receiver operating characteristic (ROC) curves of the USSS score and LSM for F4 patients were 0.849 and 0.729, respectively. On the basis of ROC curves, criteria of USSS ≥6: LSM ≥17.4 had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 89.2%:77.6%, 69.4%:61.4%, 86.5%:83.7%, 74.6%:51.9% and 0.83:0.73, respectively, in predicting F4.

CONCLUSIONS

The results indicate that this USSS has comparable efficacy to LSM in the diagnosis of cirrhosis.

Ultrasonographic scoring system score versus liver stiffness measurement in prediction of cirrhosis

Background/Aims

We compared the cirrhosis-prediction accuracy of an ultrasonographic scoring system (USSS) combining six representative sonographic indices with that of liver stiffness measurement (LSM) by transient elastography, and prospectively investigated the correlation between the USSS score and LSM in predicting cirrhosis.

Methods

Two hundred and thirty patients with chronic liver diseases (187 men, 43 women; age, 50.4±9.5 y, mean±SD) were enrolled in this prospective study. The USSS produces a combined score for nodularity of the liver surface and edge, parenchyma echogenicity, presence of right-lobe atrophy, spleen size, splenic vein diameter, and abnormality of the hepatic vein waveform. The correlations of the USSS score and LSM with that of a pathological liver biopsy (METAVIR scoring system: F0-F4) were evaluated.

Results

The mean USSS score and LSM were 7.2 and 38.0 kPa, respectively, in patients with histologically overt cirrhosis (F4, P=0.017) and 4.3 and 22.1 kPa in patients with fibrotic change without overt cirrhosis (F0-F3) (P=0.025). The areas under the receiver operating characteristic (ROC) curves of the USSS score and LSM for F4 patients were 0.849 and 0.729, respectively. On the basis of ROC curves, criteria of USSS ≥6: LSM ≥17.4 had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 89.2%:77.6%, 69.4%:61.4%, 86.5%:83.7%, 74.6%:51.9% and 0.83:0.73, respectively, in predicting F4.

Conclusions

The results indicate that this USSS has comparable efficacy to LSM in the diagnosis of cirrhosis.

Hepatic vein waveform and splenomegaly predict improvement of prothrombin time after splenectomy in hepatitis C virus-related cirrhotic patients

AIM

Whether hepatic function can recover in cirrhotic patients after splenectomy remains controversial.

METHODS

All consecutive Japanese patients with hepatic cirrhosis due to hepatitis C who had undergone elective splenectomy in Kyushu University Hospital between January 2008 and December 2009 were included in this retrospective study. Prothrombin time, serum albumin and total bilirubin concentrations were reviewed before and after splenectomy and analyzed to clarify whether splenectomy improves hepatic function in patients with cirrhosis and to determine the factors predictive of improvement in hepatic function.

RESULTS

Prothrombin time and total serum bilirubin concentration improved after splenectomy; however, serum albumin concentrations did not increase significantly. Twelve months after splenectomy, total serum bilirubin had decreased by over 0.3 mg/dL in 52.3% of patients and prothrombin time had improved by over 10% in 52.3% of patients. Multiple linear regression analysis identified hepatic vein waveform (HVWF) type I (P = 0.0174) and spleen weight (P = 0.0394) as independent predictors of improvement in prothrombin time and preoperative total serum bilirubin (P = 0.0002) as the only independent predictor of decrease in total bilirubin. Total bilirubin and prothrombin time were significantly improved after splenectomy in patients with HVWF type I, however, they were not improved in patients with HVWF type II.

CONCLUSION

Prothrombin time and total bilirubin improve in approximately half of cirrhotic patients within a year after splenectomy. HVWF type I and splenomegaly may be predictive factors for improvement in prothrombin time after splenectomy in patients with cirrhosis due to hepatitis C.

On the implementation of an automated acoustic output optimization algorithm for subharmonic aided pressure estimation

Incident acoustic output (IAO) dependent subharmonic signal amplitudes from ultrasound contrast agents can be categorized into occurrence, growth or saturation stages. Subharmonic aided pressure estimation (SHAPE) is a technique that utilizes growth stage subharmonic signal amplitudes for hydrostatic pressure estimation. In this study, we developed an automated IAO optimization algorithm to identify the IAO level eliciting growth stage subharmonic signals and also studied the effect of pulse length on SHAPE. This approach may help eliminate the problems of acquiring and analyzing the data offline at all IAO levels as was done in previous studies and thus, pave the way for real-time clinical pressure monitoring applications. The IAO optimization algorithm was implemented on a Logiq 9 (GE Healthcare, Milwaukee, WI) scanner interfaced with a computer. The optimization algorithm stepped the ultrasound scanner from 0% to 100% IAO. A logistic equation fitting function was applied with the criterion of minimum least squared error between the fitted subharmonic amplitudes and the measured subharmonic amplitudes as a function of the IAO levels and the optimum IAO level was chosen corresponding to the inflection point calculated from the fitted data. The efficacy of the optimum IAO level was investigated for in vivo SHAPE to monitor portal vein (PV) pressures in 5 canines and was compared with the performance of IAO levels, below and above the optimum IAO level, for 4, 8 and 16 transmit cycles. The canines received a continuous infusion of Sonazoid microbubbles (1.5 μl/kg/min; GE Healthcare, Oslo, Norway). PV pressures were obtained using a surgically introduced pressure catheter (Millar Instruments, Inc., Houston, TX) and were recorded before and after increasing PV pressures. The experiments showed that optimum IAO levels for SHAPE in the canines ranged from 6% to 40%. The best correlation between changes in PV pressures and in subharmonic amplitudes (r=-0.76; p=0.24), and between the absolute PV pressures and the subharmonic amplitudes (r=-0.89; p<0.01) were obtained for the optimized IAO and 4 transmit cycles. Only for the optimized IAO and 4 transmit cycles did the subharmonic amplitudes differ significantly (p<0.01) before and after increasing PV pressures. A new algorithm to identify optimum IAO levels for SHAPE has been developed and validated with the best results being obtained for 4 transmit cycles. The work presented in this study may pave the way for real-time clinical applications of estimating pressures using the subharmonic signals from ultrasound contrast agents.

Relationship between the hepatic venous pressure gradient and first variceal hemorrhage in patients with cirrhosis: a multicenter retrospective study in Korea

Background/Aims

Variceal hemorrhage is one of the major complications of cirrhosis and is associated with significant mortality and morbidity. The development of gastroesophageal varices and variceal hemorrhage is the most direct consequence of portal hypertension. Correlations between the hepatic venous pressure gradient (HVPG) and first variceal hemorrhage were examined.

Methods

Patients with cirrhosis who underwent HVPG measurement between July 2009 and September 2010 were enrolled (n=535). All patients underwent esophagogastroduodenoscopy to enable the evaluation of gastroesophageal varices.

Results

The HVPG for all patients was 16.46±7.05 mmHg (mean±SD), and was significantly higher among those with first variceal hemorrhage than in those without it. The HVPG was significantly correlated with both Child-Turcotte-Pugh (r=0.488, P<0.001) and Model for End-stage Liver Disease (r=0.478, P<0.001) scores. An HVPG value of 11 mmHg was predictive of first variceal hemorrhage with a sensitivity of 92.4% and a specificity of 27.7%.

Conclusions

The HVPG was higher in patients with first variceal hemorrhage than in those without it.

Investigating the efficacy of subharmonic aided pressure estimation for portal vein pressures and portal hypertension monitoring

The efficacy of using subharmonic emissions from Sonazoid microbubbles (GE Healthcare, Oslo, Norway) to track portal vein pressures and pressure changes was investigated in 14 canines using either slow- or high-flow models of portal hypertension (PH). A modified Logiq 9 scanner (GE Healthcare, Milwaukee, WI, USA) operating in subharmonic mode (f(transmit): 2.5 MHz, f(receive): 1.25 MHz) was used to collect radiofrequency data at 10-40% incident acoustic power levels with 2-4 transmit cycles (in triplicate) before and after inducing PH. A pressure catheter (Millar Instruments, Inc., Houston, TX, USA) provided reference portal vein pressures. At optimum insonification, subharmonic signal amplitude changes correlated with portal vein pressure changes; r ranged from -0.82 to -0.94 and from -0.70 to -0.73 for PH models considered separately or together, respectively. The subharmonic signal amplitudes correlated with absolute portal vein pressures (r: -0.71 to -0.79). Statistically significant differences between subharmonic amplitudes, before and after inducing PH, were noted (p ≤ 0.01). Portal vein pressures estimated using subharmonic aided pressure estimation did not reveal significant differences (p > 0.05) with respect to the pressures obtained using the Millar pressure catheter. Subharmonic-aided pressure estimation may be useful clinically for portal vein pressure monitoring.

Predicting portal hypertension as assessed by acoustic radiation force impulse: correlations with the Doppler ultrasound

OBJECTIVE

The purpose of this study was to assess the value of acoustic radiation force impulse (ARFI) for evaluating portal hypertension by correlating the elasticity of liver cirrhosis, as measured by ARFI, with haemodynamic indices measured by Doppler ultrasound.

METHODS

We evaluated the data of a total of 154 prospectively enrolled patients who underwent both duplex Doppler ultrasound and ARFI imaging. The duplex Doppler ultrasound indices, including the mean portal vein velocity, splenic index (SI) and splenoportal index (SPI) were evaluated to determine the statistical correlation with shear wave velocity (SWV) of ARFI. We also analysed the differences in the correlations between the SI, SPI and SWV of the group who had varices. The correlations were assessed with Spearman's rank correlation coefficients.

RESULTS

There was an increase of SWV in parallel with the increase of the SI (ρ=0.409, p<0.01) and SPI (ρ=0.451, p<0.01). In the patient group who did not have varices (n=74), the Doppler indices were found to be more correlated with the SWV (SI: ρ=0.447, SPI: ρ=0.552, p<0.01). However, the group with varices showed no correlation between the SWV and the Doppler parameters.

CONCLUSION

SWV of ARFI was well correlated statistically with Doppler parameters, but is of limited value in predicting portal hypertension directly owing to great variability of Doppler parameters. By evaluating the correlation between ARFI and Doppler ultrasound, we suggest that the SWV might be a non-invasive supplementary tool for predicting portal hypertension.

Hepatic vein arrival time as assessed by contrast-enhanced ultrasonography is useful for the assessment of portal hypertension in compensated cirrhosis

The measurement of the hepatic venous pressure gradient (HVPG) for the estimation of portal hypertension (PH) in cirrhosis has some limitations, including its invasiveness. Hepatic vein arrival time (HVAT), as assessed by microbubble contrast-enhanced ultrasonography (CEUS), is negatively correlated with the histological grade of liver fibrosis because of the associated hemodynamic abnormalities. Anatomical and pathophysiological changes in liver microcirculation are the initial events leading to PH. However, the direct relationship between HVAT and PH has not been evaluated. The present study measured both HVPG and HVAT in 71 consecutive patients with compensated cirrhosis and analyzed the relationship between the two parameters (i.e., the derivation set). Results were validated in 35 compensated patients with cirrhosis at another medical center (i.e., the validation set). The derivation set had HVPG and HVAT values of 11.4 ± 5.0 mmHg (mean ± standard deviation; range, 2-23) and 14.1 ± 3.4 seconds (range, 8.4-24.2), respectively; there was a statistically significant negative correlation between HVPG and HVAT (r(2) = 0.545; P < 0.001). The area under the receiver operating characteristic curve (AUROC) was 0.973 for clinically significant PH (CSPH; HVPG, ≥ 10 mmHg), and the sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios for CSPH for an HVAT cut-off value of 14 seconds were 92.7%, 86.7%, 90.5%, 89.7%, 6.95, and 0.08, respectively. In addition, a shorter HVAT was associated with worse Child-Pugh score (P < 0.001) and esophageal varices (P = 0.018). In the validation set, there was also a significant negative correlation between HVAT and HVPG (r(2) = 0.538; P < 0.001), and AUROC = 0.953 for CSPH. HVAT was significantly correlated with PH. These results indicate that measuring HVAT is useful for the noninvasive prediction of CSPH in patients with compensated cirrhosis.

Accelerated phase-contrast cine MRI using k-t SPARSE-SENSE

Phase-contrast (PC) cine MRI is a promising method for assessment of pathologic hemodynamics, including cardiovascular and hepatoportal vascular dynamics, but its low data acquisition efficiency limits the achievable spatial and temporal resolutions within clinically acceptable breath-hold durations. We propose to accelerate PC cine MRI using an approach which combines compressed sensing and parallel imaging (k-t SPARSE-SENSE). We validated the proposed 6-fold accelerated PC cine MRI against 3-fold accelerated PC cine MRI with parallel imaging (generalized autocalibrating partially parallel acquisitions). With the programmable flow pump, we simulated a time varying waveform emulating hepatic blood flow. Normalized root mean square error between two sets of velocity measurements was 2.59%. In multiple blood vessels of 12 control subjects, two sets of mean velocity measurements were in good agreement (mean difference = -0.29 cm/s; lower and upper 95% limits of agreement = -5.26 and 4.67 cm/s, respectively). The mean phase noise, defined as the standard deviation of the phase in a homogeneous stationary region, was significantly lower for k-t SPARSE-SENSE than for generalized autocalibrating partially parallel acquisitions (0.05 ± 0.01 vs. 0.19 ± 0.06 radians, respectively; P < 0.01). The proposed 6-fold accelerated PC cine MRI pulse sequence with k-t SPARSE-SENSE is a promising investigational method for rapid velocity measurement with relatively high spatial (1.7 mm × 1.7 mm) and temporal (∼35 ms) resolutions.

Histological subclassification of cirrhosis using the Laennec fibrosis scoring system correlates with clinical stage and grade of portal hypertension

BACKGROUND & AIMS

Further histological subclassification of cirrhosis may be useful because of heterogeneity of severity within cirrhosis. We aimed to determine the relationship between histological subclassification and clinical stage of cirrhosis as well as grade of portal hypertension.

METHODS

One hundred-twenty-three biopsy-proven cirrhosis patients, whose clinical stage of cirrhosis and hepatic venous pressure gradient (HVPG) could be estimated, were included in this prospective study. Histology of cirrhosis was blindly subclassified using the Laennec fibrosis scoring system semi-quantitatively without knowledge of the clinical stage or the HVPG results. The Laennec system subclassifies cirrhosis as mild - thin septa, moderate - at least two broad septa, and severe - at least one very broad septum or many minute nodules. Clinical stages were determined by the presence or absence of varices, ascites, and variceal hemorrhage. Biological and laboratory data were also collected.

RESULTS

Alcohol intake was the most common cause of cirrhosis in this cohort (87, 70.7%). Histology of cirrhosis subclassified using the Laennec scoring system significantly correlated with both the clinical stage of cirrhosis (p < 0.001) and HVPG (mild: 8.1 ± 2.6 mm Hg, moderate: 12.4 ± 3.3mm Hg, severe: 16.3 ± 4.0 mm Hg, p < 0.001). With higher grades of histological subclassification of cirrhosis, increased frequency in both severe portal hypertension (HVPG ≥ 12 mm Hg) and episodes of variceal hemorrhage were observed (p < 0.001).

CONCLUSIONS

Histological subclassification of cirrhosis by the Laennec fibrosis scoring system is tightly correlated with both the clinical stage of cirrhosis and grade of portal hypertension. This suggests that cirrhosis should be subclassified into different stages according to its histological severity.

Assessment of intrahepatic blood flow by Doppler ultrasonography: relationship between the hepatic vein, portal vein, hepatic artery and portal pressure measured intraoperatively in patients with portal hypertension

BACKGROUND

Abnormality of hepatic vein (HV) waveforms evaluated by Doppler ultrasonography has been widely studied in patients with chronic liver disease. We investigated the correlation between changes in HV waveforms and portal vein velocity (PVVel), the hepatic artery pulsatility index (HAPI), and also the extent of abnormal Doppler HV waveforms expressed as damping index (DI), severity of portal hypertension expressed as Child-Pugh scores and portal pressure (PP) measured directly from patients with portal hypertension (PHT) to evaluate the indicative value of abnormal HV waveforms and discuss the cause of abnormal HV waveform.

METHODS

Sixty patients who had been diagnosed with PHT and accepted surgical therapy of portosystemic shunts were investigated. PP was measured intraoperatively. Thirty healthy volunteers with no history of chronic liver disease were enrolled as the control group. HV waveforms were categorized as triphasic, biphasic or monophasic. DI was compared as the quantitative indicator of abnormal HV waveforms. Another two Doppler parameters, PVVel and HAPI were also measured. These Doppler features were compared with PP, Child-Pugh scores and histological changes assessed by liver biopsy.

RESULTS

In the patient group, the Doppler flow waveforms in the middle HV were triphasic in 31.6%, biphasic in 46.7%, and monophasic in 21.6% of subjects. These figures were 86.7%, 10.0%, and 3.3%, respectively, in healthy subjects. With the flattening of HV waveforms, the HAPI increased significantly (r = 00.438, p < 0.0001), whereas PVVel decreased significantly (r = -0.44, p <0.0001). Blood flow parameters, HAPI, PVVel and HV-waveform changes showed no significant correlations with Child-Pugh scores. The latter showed a significant correlation with PP (r = 0.589, p = 0.044). Changes of HV waveform and DI significantly correlated with PP (r = 0.579, r = 0.473, p <0.0001), and significant correlation between DI and Child-Pugh scores was observed (r = 0.411, p = 0.001). PP was significantly different with respect to nodule size (p < 0.05), but HV-waveform changes were not significantly correlated with pathological changes.

CONCLUSION

In patients with PHT, a monophasic HV waveform indicates higher portal pressure. Furthermore, quantitative indicator DI can reflect both higher portal pressure and more severe liver dysfunction. Flattening of HV waveforms accompanied by an increase in the HAPI and decrease in PVVel support the hypothesis that histological changes reducing HV compliance be the cause of abnormality of Doppler HV waveforms from the hemodynamic angle.

Changing waveform during respiration on hepatic vein Doppler sonography of severe portal hypertension: comparison with the damping index

OBJECTIVES

The purposes of this study were to assess retrospectively whether the waveform change during respiration on hepatic vein Doppler sonography is a parameter of severe portal hypertension as estimated by the hepatic venous pressure gradient (HVPG) and to compare with a hepatic vein damping index (DI) at expiration.

METHODS

Spectral Doppler sonography of the hepatic vein was performed on 22 consecutive patients who underwent HVPG measurement for portal hypertension with liver cirrhosis. From the maximum and minimum velocities of systolic hepatofugal venous flow on Doppler sonography, 3 parameters were derived: damping index at expiration (DI(exp)), damping index ratio (DI(ratio)), and damping index difference (ΔDI) between inspiration and expiration. Considering an HVPG level of 12 mm Hg or higher as the threshold level for high-grade portal hypertension, we assessed the diagnostic capability of these Doppler sonographic parameters to discriminate using receiver operating characteristic curve analysis.

RESULTS

Area under the curve values for the DI(ratio) and ΔDI (0.875 and 0.889, P = .807 and .682, respectively) were slightly higher than the area for the DI(exp) (0.861; respectively). When the DI(exp) was greater than 0.56, the sensitivity and specificity for high-grade portal hypertension were 66.7% and 100.0%, respectively. In the case of the DI(ratio), the sensitivity and specificity were 77.8%, and 100.0% at greater than 0.69. The corresponding sensitivity and specificity at a value of 0.25 or less for the ΔDI were 83.3% and 100.0%.

CONCLUSIONS

The ratio and difference of the DI of the hepatic vein waveform are helpful parameters in assessing the severity of portal hypertension as well as using the existing DI on its own.

Noninvasive analysis of portal pressure by contrast-enhanced sonography in patients with cirrhosis

OBJECTIVES

Free portal pressure measurement is a reliable method for assessment of portal pressure in patients with cirrhosis. Intrahepatic circulatory time analysis of a sonographic contrast agent can assess liver fibrosis and its severity. The purposes of this pilot study were to assess the correlation between the intrahepatic circulatory time and free portal pressure and to assess whether intrahepatic circulatory time analysis can be used to predict portal venous pressure severity.

METHODS

The intrahepatic circulatory time and free portal pressure were measured in 31 patients with hepatitis B virus-related liver disease. Pearson correlation analysis was used to assess the correlation between the intrahepatic circulatory time and free portal pressure.

RESULTS

The hepatic vein-hepatic artery interval times were significantly shorter in the portal hypertension group than the non-portal hypertension group (mean ± SD, 8.26 ± 1.94 and 13.83 ± 1.17 seconds, respectively; P < .001). The portal vein-hepatic artery interval times were significantly longer in the portal hypertension group than the nonportal hypertension group (13.13 ± 2.25 and 7.25 ± 1.81 seconds; P < .001). Considering the whole patient population, there were statistically significant correlations between free portal pressure and the hepatic vein-hepatic artery interval time (r = -0.900; P < .001) and portal vein-hepatic artery interval time (r = 0.808; P < .001). In patients with portal hypertension, there was a statistically significant correlation between free portal pressure and the hepatic vein-hepatic artery interval time (r = -0.804; P = .009) and a weak correlation between free portal pressure and the portal vein-hepatic artery interval time (r = 0.506; P = .036).

CONCLUSIONS

Intrahepatic circulatory time measurement is correlated with free portal pressure and has the potential capability to evaluate portal pressure noninvasively in patients with hepatitis B virus-related liver disease.

Doppler assessment of hepatic venous waves for predicting large varices in cirrhotic patients

BACKGROUND/AIM

Color Doppler examination of changes in hepatic venous waveforms is being evaluated as a means of prediction of severity of portal hypertension and presence of esophageal varices. Normal hepatic venous waveform shows a triphasic pattern. In cirrhosis, this pattern changes to a biphasic or monophasic pattern. We aimed to study the sensitivity of loss of normal hepatic venous waveforms in predicting large varices in a cross-sectional analysis.

MATERIALS AND METHODS

All patients, admitted or attending the outpatient department, with a diagnosis of cirrhosis were included in the study. All patients were subjected to oesophagogastroduodenoscopy and Color Doppler examination, and waveform patterns in hepatic vein were recorded. The sensitivity and specificity of changes in waveform in detecting large varices were studied.

RESULTS

A total of 51 cases were examined. Triphasic waves were seen in 4 (7.8%) cases, biphasic in 26 (51%) cases, and monophasic in 21 (41.2%) cases. Small varices were seen in 30 (58.8%) cases and large varices in 21 (41.2%) cases. The sensitivity of loss of the triphasic wave pattern in detecting significant varices (Grade 3 or 4) was very high (95.23%) and negative predictive value was also high (75%). Severity of liver disease as indicated by Child-Pugh and MELD scores did not correlate with changes in hepatic venous waveforms.

CONCLUSION

Loss of triphasic hepatic venous waveform is highly sensitive in predicting significant varices in patients with cirrhosis.

Portal hypertensive gastropathy: correlation with portal hypertension and prognosis in cirrhosis

BACKGROUND

Portal hypertensive gastropathy (PHG) is a common endoscopic finding in patients with cirrhosis. However, the relationship between PHG and portal hypertension is controversial. Furthermore, nothing is known regarding the correlation between PHG and prognosis in patients with cirrhosis.

METHODS

The hepatic venous pressure gradient (HVPG), endoscopic PHG grade, Child-Pugh score, and model for end-stage liver disease (MELD) score were assessed at baseline and were followed prospectively in 331 cirrhotic patients (284 males, 85.8%; mean age, 52.16 ± 9.05 years) from January 2001 to April 2009. The relationship between PHG with HVPG and survival was investigated.

RESULTS

The HVPG was significantly higher in patients with severe PHG than in those with mild or no PHG (absent, 4.9 ± 1.7 mmHg; mild, 10.7 ± 4.1 mmHg; severe, 15.6 ± 4.6 mmHg; P < 0.001). During follow-up, 28 patients (8.5%) died from liver-related disease. In the Cox regression analysis, severe PHG (none and mild vs. severe) (hazard ratio 1.153, 95% confidence interval: 1.048-1.269) showed a significantly high relative risk of mortality, and in the Kaplan-Meier analysis, severe PHG showed a significantly shorter expected survival time than none or mild PHG (median survival time, 77.6 ± 9.6 months in severe PHG; log-rank test, P = 0.030).

CONCLUSIONS

PHG was associated with portal hypertension severity and prognosis in patients with cirrhosis.

[Pathophysiology of portal hypertension, what's new?]

Portal hypertension (PHT) is associated with changes in the intrahepatic, systemic and portosystemic collateral circulations. Alteration in vasoreactivity (vasodilation and vasoconstriction) plays a central role in the pathogenesis of PHT by contributing to increased intrahepatic resistance, hyperdynamic circulation and the expansion of the collateral circulation. PHT is also importantly characterized by changes in vascular structure; termed vascular remodeling, which is an adaptive response of the vessel wall that occurs in response to chronic changes in the environment such as shear stress. Angiogenesis, the sprouting of new blood vessels, also occurs in PHT, especially in the expansion of the portosystemic collateral circulation. These complementary processes of vasoreactivity, vascular remodeling and angiogenesis represent important targets in the research for the treatment of portal hypertension.

[Recent advances in diagnosis of portal hypertension]

Complications of portal hypertension are major concerns in liver cirrhosis and significant morbidity and mortality mainly because of variceal bleeding, ascites, bacterial infections, hepatic encephalopathy, and hepatorenal syndrome. Various modalities in the diagnosis of portal hypertension are reviewed. The measurement of hepatic venous pressure gradient (HVPG) is a simple, invasive, reproducible method and regarded as the gold standard for the diagnosis and staging of portal hypertension. Other tests such as transient elastography, per-endoscopic variceal pressure measurement, endoscopic ultrasonography, and Doppler ultrasonography may be complementary and promising.

Understanding the spectral Doppler waveform of the hepatic veins in health and disease

Duplex Doppler sonography is a fundamental component of the complete ultrasonographic examination of the liver. Accurate interpretation of the spectral Doppler tracing from the hepatic veins is valuable, as it reflects important cardiac and hepatic physiology. Normally, there are four phases: A, S, V, and D; the S and D waves indicate flow in the antegrade direction toward the heart. In hepatic and cardiac disease, these normal waves may be absent, a finding indicative of flow in a nonphysiologic manner. In addition, transient patient factors such as phase of the respiratory cycle may influence the appearance of the spectral tracing. Familiarity with the normal and abnormal spectral Doppler waveforms from the hepatic veins and knowledge of their respective physiology and pathophysiology provide valuable insights. Systematic analysis of the direction, regularity, and phasicity of the spectral tracing and the ratio of the amplitudes of the S and D waves allows one to arrive at the correct differential diagnosis in most situations.

Current status of liver diseases in Korea: liver cirrhosis

Liver cirrhosis represents the final common pathway of virtually all chronic liver diseases, and is characterized by an accumulation of extracellular matrix rich in fibrillar collagens. Patients with cirrhosis are at risk of developing many potential complications. The most common complication seen in patients with liver cirrhosis is ascites, and the most lethal one is bleeding varices. Other intermediate and late stage complications include spontaneous bacterial peritonitis, hepatic encephalopathy, and hepatorenal syndrome. The mortality and morbidity attributable to liver disease in Korea have decreased continuously over the past decades, probably due to the implementation of universal vaccination and potent antiviral therapies. In addition, recent advances in the understanding of the pathophysiology of cirrhosis and in various management approaches to cirrhosis complications will contribute to the steady improvement in patient outcomes in this country. This review article outlines recent changes in etiologies and prognosis, and the advances in management of cirrhosis in Korea.